Variable magnification imaging optical system

Abstract

To provide a zoom imaging optical system which is reduced in size and weight, and yet suppresses magnification chromatic aberration and axial chromatic aberration while zooming, features high-speed focusing with minimized performance deterioration in a short distance range, and offers good optical performance over an entire zoom range from infinity to a short distance.SOLUTION: A zoom imaging optical system disclosed herein consists of a positive first lens group G1, a positive second lens group G2, a negative third lens group G3, a first intermediate group GM1 consisting of one or more lens groups and an aperture stop, a second intermediate group GM2, and a succeeding group GR consisting of one or more lens groups, arranged in order from the object side, and is configured to change inter-lens group distances while zooming or focusing. When zooming from the wide-angle end to the telephoto end, the first lens group G1 moves toward the object side while the second lens group G2 is stationary, increasing the distance between the first lens group G1 and the second lens group G2 and reducing the distance between the second lens group G2 and the third lens group G3. At least the second intermediate group GM2 moves while focusing.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a variable magnification imaging optical system suitable for an imaging optical system used in imaging devices such as digital cameras and video cameras.

Background Art

[0002] In recent years, as mirrorless cameras such as digital cameras and video cameras have become more prevalent, high-performance cameras have been installed in smartphones and mobile data terminals. To differentiate themselves from these mobile devices, there has been an increasing demand for super-telephoto zoom lenses in digital cameras and video cameras.

[0003] In addition, in recent years, digital cameras and video cameras have further advanced in the high pixel count of imaging elements, and the demand for higher performance in imaging optical systems has increased even more.

[0004] Patent Documents 1 to 4 describe examples of variable magnification imaging optical systems with a half angle of view at the telephoto end of approximately 3 degrees or less.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0006] For super-telephoto zoom lenses with a narrow field of view at the telephoto end, it is necessary to achieve three things simultaneously: a large zoom ratio to improve usability as a zoom lens, miniaturization to improve portability, and image formation performance.

[0007] To achieve a large magnification ratio, it is common practice to place the lens group with the most positive refractive power closest to the object and extend it toward the object through magnification, thereby maximizing the telephoto ratio (the optical length divided by the focal length) at the telephoto end and improving image formation performance at telephoto focal lengths.

[0008] In telephoto lenses, aberrations generated in the converging lens group located near the object are amplified by the rear lens group. With a prime lens, image performance can be improved simply by suppressing the aberrations generated in the object-side converging system based on this relationship. However, with zoom lenses, various aberrations fluctuate due to changes in power distribution caused by the magnification, making it impossible to simplify the process as with prime lenses. In particular, chromatic aberration, which is a problem in lenses in the super-telephoto range with a narrow field of view, changes direction as the magnification changes. Therefore, in order to reduce the size of the optical system while suppressing chromatic aberration across the entire zoom range, it is important to select optical materials that correspond to the changes in power distribution caused by the magnification.

[0009] Furthermore, when attempting to increase the magnification in the telephoto range, the image formation performance at close range deteriorates with a single focus group. Therefore, a method is known that uses multiple focus groups to improve image formation performance at close range.

[0010] The optical system described in Patent Document 1 is an example of a fixed-length super-telephoto zoom lens. Although aberrations are suppressed throughout the entire zoom range and the imaging performance is high, attempting to increase the magnification ratio while maintaining imaging performance in such a fixed-length type optical system results in a significantly enlarged optical system, which is undesirable.

[0011] The optical system described in Patent Document 2 is an example of a super-telephoto zoom lens with a variable overall length in which the first lens group extends. However, the back focus (distance from the final lens to the image plane) is large relative to the total optical length, and considering the shortened flange back due to the recent shift to mirrorless cameras, it is insufficient in terms of miniaturizing the optical system. Furthermore, the chromatic aberration of magnification varies greatly from the wide-angle end to the telephoto end, and the correction is insufficient.

[0012] The optical system described in Patent Document 3 is an example of a super-telephoto zoom lens that supports a short flange back, but the chromatic aberration of magnification varies greatly from the wide-angle end to the telephoto end, the correction is insufficient, and the suppression of the overall optical length at the wide-angle end is also insufficient.

[0013] Patent Document 4 includes an example of a super-telephoto zoom lens with multiple focus groups, which maintains good performance even at a magnification exceeding 0.2x at the telephoto end. However, the magnification ratio is small, around 2x, and the miniaturization of the optical system is insufficient.

[0014] This invention has been made in view of these problems, and aims to provide a variable-magnification imaging optical system that achieves miniaturization and weight reduction while suppressing magnification chromatic aberration and axial chromatic aberration during magnification, has fast focusing and suppresses performance degradation at close distances, and has good optical performance from infinity to very close distances throughout the entire zoom range. [Means for solving the problem]

[0015] To solve the above problem, the lens assembly consists of, in order from the object side, a first lens group G1 having positive refractive power, a second lens group G2 having positive refractive power, a third lens group G3 having negative refractive power, a first intermediate group GM1 consisting of one or more lens groups including an aperture diaphragm S, a second intermediate group GM2, and a subsequent group GR consisting of one or more lens groups. The aforementioned second lens group G2 includes one or more concave lenses. The spacing between adjacent lens groups changes during magnification or focusing, and when magnification changes from the wide-angle end to the telephoto end, the first lens group G1 moves toward the object. The aforementionedA variable magnification imaging optical system characterized in that the second lens group G2 is fixed with respect to the image plane, the distance between the first lens group G1 and the second lens group G2 increases, the distance between the second lens group G2 and the third lens group G3 decreases, and at least the second intermediate group GM2 moves along the optical axis when focusing from an object at infinity to an object at a close distance.

[0016] To solve the above problems, a variable-magnification imaging optical system is provided, comprising, in order from the object side, a first lens group G1 having positive refractive power, a second lens group G2 having positive refractive power, a third lens group G3 having negative refractive power, a first intermediate group GM1 consisting of one or more lens groups including an aperture diaphragm S, a second intermediate group GM2, and a subsequent group GR consisting of one or more lens groups, wherein the spacing between adjacent lens groups changes during magnification or focusing, and when magnifying from the wide-angle end to the telephoto end, the first lens group G1 moves toward the object side, the second lens group G2 moves toward the image side, the spacing between the first lens group G1 and the second lens group G2 increases, and the third lens group G3 moves such that the spacing between it and the second lens group G2 decreases, and when focusing from an object at infinity to an object at close range, at least the second intermediate group GM2 moves along the optical axis. [Effects of the Invention]

[0017] According to the present invention, a variable-magnification imaging optical system is provided that achieves miniaturization and weight reduction while suppressing magnification chromatic aberration and axial chromatic aberration during magnification, has focusing that is fast during focusing and suppresses performance degradation at close distances, and has good optical performance from infinity to very close distances throughout the entire zoom range. [Brief explanation of the drawing]

[0018] [Figure 1] This is a lens configuration diagram of Embodiment 1 of the variable magnification imaging optical system of the present invention when the wide-angle end is focused at infinity. [Figure 2] This is a longitudinal aberration diagram at the wide-angle end when the variable magnification imaging optical system of the present invention is in focus at infinity, according to Embodiment 1. [Figure 3] This is a longitudinal aberration diagram of the intermediate focal length at infinity focus according to Embodiment 1 of the variable magnification imaging optical system of the present invention. [Figure 4] It is a longitudinal aberration diagram at infinity focus at the telephoto end according to Example 1 of the zoom imaging optical system of the present invention. [Figure 5] It is a lateral aberration diagram at infinity focus at the wide-angle end according to Example 1 of the zoom imaging optical system of the present invention. [Figure 6] It is a lateral aberration diagram at infinity focus at the intermediate focal length according to Example 1 of the zoom imaging optical system of the present invention. [Figure 7] It is a lateral aberration diagram at infinity focus at the telephoto end according to Example 1 of the zoom imaging optical system of the present invention. [Figure 8] It is a lateral aberration diagram at focus when the object distance is 2.8 m at the wide-angle end according to Example 1 of the zoom imaging optical system of the present invention. [Figure 9] It is a lateral aberration diagram at focus when the object distance is 2.8 m at the intermediate focal length according to Example 1 of the zoom imaging optical system of the present invention. [Figure 10] It is a lateral aberration diagram at focus when the object distance is 2.8 m at the telephoto end according to Example 1 of the zoom imaging optical system of the present invention. [Figure 11] It is a lens configuration diagram at infinity focus at the wide-angle end according to Example 2 of the zoom imaging optical system of the present invention. [Figure 12] It is a longitudinal aberration diagram at infinity focus at the wide-angle end according to Example 2 of the zoom imaging optical system of the present invention. [Figure 13] It is a longitudinal aberration diagram at infinity focus at the intermediate focal length according to Example 2 of the zoom imaging optical system of the present invention. [Figure 14] It is a longitudinal aberration diagram at infinity focus at the telephoto end according to Example 2 of the zoom imaging optical system of the present invention. [Figure 15] It is a lateral aberration diagram at infinity focus at the wide-angle end according to Example 2 of the zoom imaging optical system of the present invention. [Figure 16] It is a lateral aberration diagram at infinity focus at the intermediate focal length according to Example 2 of the zoom imaging optical system of the present invention. [Figure 17] It is a lateral aberration diagram at infinity focus at the telephoto end according to Example 2 of the zoom imaging optical system of the present invention. [Figure 18] It is a lateral aberration diagram at focus when the object distance is 2.5 m at the wide-angle end according to Example 2 of the zoom imaging optical system of the present invention. [Figure 19] This is a lateral aberration diagram of the intermediate focal length at an object distance of 2.5m, according to Embodiment 2 of the variable magnification imaging optical system of the present invention. [Figure 20] This is a lateral aberration diagram of Embodiment 2 of the variable magnification imaging optical system of the present invention when the object distance at the telephoto end is 2.5m and in focus. [Figure 21] This is a lens configuration diagram for the wide-angle end at infinity focus according to Embodiment 3 of the variable magnification imaging optical system of the present invention. [Figure 22] This is a longitudinal aberration diagram at the wide-angle end when infinity focus is achieved, according to Embodiment 3 of the variable magnification imaging optical system of the present invention. [Figure 23] This is a longitudinal aberration diagram at infinity focus according to Embodiment 3 of the variable magnification imaging optical system of the present invention. [Figure 24] This is a longitudinal aberration diagram at infinity focus at the telephoto end according to Embodiment 3 of the variable magnification imaging optical system of the present invention. [Figure 25] This is a diagram of the lateral aberration at the wide-angle end when the variable magnification imaging optical system of the present invention is in focus at infinity, according to Embodiment 3 of the present invention. [Figure 26] This is a diagram of the transverse aberration at infinity focus according to Embodiment 3 of the variable magnification imaging optical system of the present invention. [Figure 27] This is a diagram of the transverse aberration at infinity focus at the telephoto end according to Embodiment 3 of the variable magnification imaging optical system of the present invention. [Figure 28] This is a lateral aberration diagram of the wide-angle end at an object distance of 2.5m, according to Embodiment 3 of the variable magnification imaging optical system of the present invention. [Figure 29] This is a lateral aberration diagram for Embodiment 3 of the variable magnification imaging optical system of the present invention, when the object distance is 2.5m and the intermediate focal length is in focus. [Figure 30] This is a lateral aberration diagram for Embodiment 3 of the variable magnification imaging optical system of the present invention, when the object distance at the telephoto end is 2.4m and in focus. [Figure 31] This is a lens configuration diagram for Embodiment 4 of the variable magnification imaging optical system of the present invention, when the wide-angle end is focused at infinity. [Figure 32] This is a longitudinal aberration diagram at the wide-angle end when the variable magnification imaging optical system of the present invention is in focus at infinity, according to Embodiment 4. [Figure 33] This is a longitudinal aberration diagram of the intermediate focal length at infinity focus according to Embodiment 4 of the variable magnification imaging optical system of the present invention. [Figure 34] This is a longitudinal aberration diagram at infinity focus at the telephoto end according to Embodiment 4 of the variable magnification imaging optical system of the present invention. [Figure 35] This is a diagram of the lateral aberration at the wide-angle end when the variable magnification imaging optical system of the present invention is in focus at infinity, according to Embodiment 4. [Figure 36] This is a diagram of the transverse aberration at infinity focus according to Embodiment 4 of the variable magnification imaging optical system of the present invention. [Figure 37] This is a diagram of the transverse aberration at infinity focus at the telephoto end according to Embodiment 4 of the variable magnification imaging optical system of the present invention. [Figure 38] This is a lateral aberration diagram of Embodiment 4 of the variable magnification imaging optical system of the present invention when the object distance is 2.5m at the wide-angle end and in focus. [Figure 39] This is a lateral aberration diagram for Embodiment 4 of the variable magnification imaging optical system of the present invention, when the object distance is 2.5m and the intermediate focal length is in focus. [Figure 40] This is a lateral aberration diagram of Embodiment 4 of the variable magnification imaging optical system of the present invention when the object distance at the telephoto end is 2.4m in focus. [Figure 41] This is a lens configuration diagram for the wide-angle end at infinity focus according to Embodiment 5 of the variable magnification imaging optical system of the present invention. [Figure 42] This is a longitudinal aberration diagram at the wide-angle end when the variable magnification imaging optical system of the present invention is in focus at infinity, according to Embodiment 5. [Figure 43] This is a longitudinal aberration diagram of the intermediate focal length at infinity focus according to Embodiment 5 of the variable magnification imaging optical system of the present invention. [Figure 44] This is a longitudinal aberration diagram at infinity focus at the telephoto end according to Embodiment 5 of the variable magnification imaging optical system of the present invention. [Figure 45] This is a diagram of the lateral aberration at the wide-angle end when the variable magnification imaging optical system of the present invention is in focus at infinity, according to Embodiment 5. [Figure 46] This is a diagram of the transverse aberration at infinity focus according to Embodiment 5 of the variable magnification imaging optical system of the present invention. [Figure 47] This is a diagram of the transverse aberration at infinity focus at the telephoto end according to Embodiment 5 of the variable magnification imaging optical system of the present invention. [Figure 48] This is a lateral aberration diagram of the wide-angle end at an object distance of 2.5m when the variable magnification imaging optical system of the present invention is in focus, according to Embodiment 5. [Figure 49] This is a lateral aberration diagram for Embodiment 5 of the variable magnification imaging optical system of the present invention, when the object distance is 2.5m and the intermediate focal length is in focus. [Figure 50] This is a lateral aberration diagram of Embodiment 5 of the variable magnification imaging optical system of the present invention when the object distance at the telephoto end is 2.4m and in focus. [Figure 51] This is a lens configuration diagram for Embodiment 6 of the variable magnification imaging optical system of the present invention, showing the lens configuration when the wide-angle end is focused at infinity. [Figure 52] This is a longitudinal aberration diagram at the wide-angle end when infinity is in focus, according to Embodiment 6 of the variable magnification imaging optical system of the present invention. [Figure 53] This is a longitudinal aberration diagram of the intermediate focal length at infinity focus according to Embodiment 6 of the variable magnification imaging optical system of the present invention. [Figure 54] This is a longitudinal aberration diagram at infinity focus at the telephoto end according to Embodiment 6 of the variable magnification imaging optical system of the present invention. [Figure 55] This is a diagram of the lateral aberration at the wide-angle end when the variable magnification imaging optical system of the present invention is in focus at infinity, according to Embodiment 6. [Figure 56] This is a lateral aberration diagram at infinity focus according to Embodiment 6 of the variable magnification imaging optical system of the present invention. [Figure 57] This is a diagram of the transverse aberration at infinity focus at the telephoto end according to Embodiment 6 of the variable magnification imaging optical system of the present invention. [Figure 58] This is a lateral aberration diagram of the wide-angle end at an object distance of 2.5m when the variable magnification imaging optical system of the present invention is in focus, according to Embodiment 6. [Figure 59] This is a lateral aberration diagram for Embodiment 6 of the variable magnification imaging optical system of the present invention, when the object distance is 2.5m and the intermediate focal length is in focus. [Figure 60] This is a lateral aberration diagram of Embodiment 6 of the variable magnification imaging optical system of the present invention when the object distance at the telephoto end is 2.5m and in focus. [Figure 61] This is a lens configuration diagram for Embodiment 7 of the variable magnification imaging optical system of the present invention, showing the lens configuration at the wide-angle end when focused at infinity. [Figure 62] This is a longitudinal aberration diagram at the wide-angle end when infinity focus is achieved, according to Embodiment 7 of the variable magnification imaging optical system of the present invention. [Figure 63] This is a longitudinal aberration diagram at infinity focus according to Embodiment 7 of the variable magnification imaging optical system of the present invention. [Figure 64] This is a longitudinal aberration diagram at infinity focus at the telephoto end according to Embodiment 7 of the variable magnification imaging optical system of the present invention. [Figure 65] This is a diagram of the lateral aberration at the wide-angle end when the variable magnification imaging optical system of the present invention is in focus at infinity, according to Embodiment 7. [Figure 66] This is a diagram of the transverse aberration at infinity focus according to Embodiment 7 of the variable magnification imaging optical system of the present invention. [Figure 67] This is a diagram of the transverse aberration at infinity focus at the telephoto end according to Embodiment 7 of the variable magnification imaging optical system of the present invention. [Figure 68] This is a lateral aberration diagram for Embodiment 7 of the variable magnification imaging optical system of the present invention, when the object distance is 3.2m at the wide-angle end and in focus. [Figure 69] This is a lateral aberration diagram for Embodiment 7 of the variable magnification imaging optical system of the present invention, when the object distance is 3.2m and the intermediate focal length is in focus. [Figure 70] This is a lateral aberration diagram of Embodiment 7 of the variable magnification imaging optical system of the present invention when the object distance at the telephoto end is 3.2m and in focus. [Figure 71] This is a lens configuration diagram for Embodiment 8 of the variable magnification imaging optical system of the present invention, showing the lens configuration at the wide-angle end when focused at infinity. [Figure 72] This is a longitudinal aberration diagram at the wide-angle end when the variable magnification imaging optical system of the present invention is in focus at infinity, according to Embodiment 8. [Figure 73] This is a longitudinal aberration diagram at infinity focus according to Embodiment 8 of the variable magnification imaging optical system of the present invention. [Figure 74] This is a longitudinal aberration diagram at infinity focus at the telephoto end according to Embodiment 8 of the variable magnification imaging optical system of the present invention. [Figure 75] This is a diagram of the lateral aberration at the wide-angle end when the variable magnification imaging optical system of the present invention is in focus at infinity, according to Embodiment 8. [Figure 76] This is a diagram of the transverse aberration at infinity focus according to Embodiment 8 of the variable magnification imaging optical system of the present invention. [Figure 77] This is a diagram of the lateral aberration at infinity focus at the telephoto end according to Embodiment 8 of the variable magnification imaging optical system of the present invention. [Figure 78] This is a lateral aberration diagram of Embodiment 8 of the variable magnification imaging optical system of the present invention when the object distance is 2.5m at the wide-angle end and in focus. [Figure 79] This is a lateral aberration diagram for Embodiment 8 of the variable magnification imaging optical system of the present invention, when the object distance is 2.5m and the intermediate focal length is in focus. [Figure 80] This is a lateral aberration diagram of Embodiment 8 of the variable magnification imaging optical system of the present invention when the object distance at the telephoto end is 2.5m and in focus. [Figure 81] This is a lens configuration diagram of the wide-angle end at infinity focus according to Embodiment 9 of the variable magnification imaging optical system of the present invention. [Figure 82] This is a longitudinal aberration diagram at the wide-angle end when the variable magnification imaging optical system of the present invention is in focus at infinity, according to Embodiment 9. [Figure 83] This is a longitudinal aberration diagram at infinity focus according to Embodiment 9 of the variable magnification imaging optical system of the present invention. [Figure 84] This is a longitudinal aberration diagram at infinity focus at the telephoto end according to Embodiment 9 of the variable magnification imaging optical system of the present invention. [Figure 85] This is a diagram of the lateral aberration at the wide-angle end when the variable magnification imaging optical system of the present invention is in focus at infinity, according to Embodiment 9. [Figure 86] This is a lateral aberration diagram at infinity focus according to Embodiment 9 of the variable magnification imaging optical system of the present invention. [Figure 87] This is a diagram of the transverse aberration at infinity focus at the telephoto end according to Embodiment 9 of the variable magnification imaging optical system of the present invention. [Figure 88] This is a lateral aberration diagram of the wide-angle end at an object distance of 2.5m when the variable magnification imaging optical system of the present invention is in focus, according to Embodiment 9. [Figure 89] This is a lateral aberration diagram of the intermediate focal length at an object distance of 2.5m, according to Embodiment 9 of the variable magnification imaging optical system of the present invention. [Figure 90] This is a lateral aberration diagram of the 9th embodiment of the variable magnification imaging optical system of the present invention when the object distance at the telephoto end is 2.5m and in focus. [Figure 91] This is a lens configuration diagram for Embodiment 10 of the variable magnification imaging optical system of the present invention, showing the lens configuration when the wide-angle end is focused at infinity. [Figure 92] This is a longitudinal aberration diagram at the wide-angle end when infinity is focused, according to Embodiment 10 of the variable magnification imaging optical system of the present invention. [Figure 93] This is a longitudinal aberration diagram at infinity focus for an intermediate focal length according to Embodiment 10 of the variable magnification imaging optical system of the present invention. [Figure 94] This is a longitudinal aberration diagram at infinity focus at the telephoto end according to Embodiment 10 of the variable magnification imaging optical system of the present invention. [Figure 95] This is a diagram of the lateral aberration at the wide-angle end when the variable magnification imaging optical system of the present invention is in focus at infinity, according to Embodiment 10. [Figure 96] This is a lateral aberration diagram at infinity focus according to Embodiment 10 of the variable magnification imaging optical system of the present invention. [Figure 97] This is a diagram of the transverse aberration at infinity focus at the telephoto end according to Embodiment 10 of the variable magnification imaging optical system of the present invention. [Figure 98] This is a lateral aberration diagram of the wide-angle end at an object distance of 3.2m when focused, according to Embodiment 10 of the variable magnification imaging optical system of the present invention. [Figure 99] This is a lateral aberration diagram for Embodiment 10 of the variable magnification imaging optical system of the present invention, when the object distance is 3.2m and the intermediate focal length is in focus. [Figure 100] This is a lateral aberration diagram of the 10th embodiment of the variable magnification imaging optical system of the present invention when the object distance at the telephoto end is 3.2m and in focus. [Figure 101] This is a lens configuration diagram of Embodiment 11 of the variable magnification imaging optical system of the present invention when the wide-angle end is focused at infinity. [Figure 102] This is a longitudinal aberration diagram at the wide-angle end when infinity is focused, according to Embodiment 11 of the variable magnification imaging optical system of the present invention. [Figure 103] This is a longitudinal aberration diagram of the intermediate focal length at infinity focus according to Embodiment 11 of the variable magnification imaging optical system of the present invention. [Figure 104] This is a longitudinal aberration diagram at infinity focus at the telephoto end according to Embodiment 11 of the variable magnification imaging optical system of the present invention. [Figure 105] This is a diagram of the lateral aberration at the wide-angle end when the variable magnification imaging optical system of the present invention is in focus at infinity, according to Embodiment 11. [Figure 106] This is a lateral aberration diagram at infinity focus according to Embodiment 11 of the variable magnification imaging optical system of the present invention. [Figure 107] This is a lateral aberration diagram at infinity focus at the telephoto end according to Embodiment 11 of the variable magnification imaging optical system of the present invention. [Figure 108]This is a lateral aberration diagram of the wide-angle end at an object distance of 2.5m when focused, according to Embodiment 11 of the variable magnification imaging optical system of the present invention. [Figure 109] This is a lateral aberration diagram for Embodiment 11 of the variable magnification imaging optical system of the present invention, when the object distance is 2.5m and the intermediate focal length is in focus. [Figure 110] This is a lateral aberration diagram of the variable magnification imaging optical system of the present invention when the object distance at the telephoto end is 2.5m and the optical system is in focus, according to Embodiment 11. [Figure 111] This is a lens configuration diagram for Embodiment 12 of the variable magnification imaging optical system of the present invention, showing the lens configuration when the wide-angle end is focused at infinity. [Figure 112] This is a longitudinal aberration diagram at the wide-angle end when focused at infinity, according to Embodiment 12 of the variable magnification imaging optical system of the present invention. [Figure 113] This is a longitudinal aberration diagram at infinity focus for an intermediate focal length according to Embodiment 12 of the variable magnification imaging optical system of the present invention. [Figure 114] This is a longitudinal aberration diagram at infinity focus at the telephoto end according to Embodiment 12 of the variable magnification imaging optical system of the present invention. [Figure 115] This is a diagram of the lateral aberration at the wide-angle end when the variable magnification imaging optical system of the present invention is in focus at infinity, according to Embodiment 12. [Figure 116] This is a lateral aberration diagram at infinity focus according to Embodiment 12 of the variable magnification imaging optical system of the present invention. [Figure 117] This is a lateral aberration diagram at infinity focus at the telephoto end according to Embodiment 12 of the variable magnification imaging optical system of the present invention. [Figure 118] This is a lateral aberration diagram of the wide-angle end at an object distance of 3.2m when focused, according to Embodiment 12 of the variable magnification imaging optical system of the present invention. [Figure 119] This is a lateral aberration diagram for an intermediate focal length at an object distance of 3.2m, according to Embodiment 12 of the variable magnification imaging optical system of the present invention. [Figure 120] This is a lateral aberration diagram of the 12th embodiment of the variable magnification imaging optical system of the present invention when the object distance at the telephoto end is 3.2m and in focus. [Figure 121] This is a lens configuration diagram for Embodiment 13 of the variable magnification imaging optical system of the present invention, showing the lens configuration at the wide-angle end when focused at infinity. [Figure 122] This is a longitudinal aberration diagram at the wide-angle end when infinity is in focus, according to Embodiment 13 of the variable magnification imaging optical system of the present invention. [Figure 123] This is a longitudinal aberration diagram of the intermediate focal length at infinity focus according to Embodiment 13 of the variable magnification imaging optical system of the present invention. [Figure 124] This is a longitudinal aberration diagram at infinity focus at the telephoto end according to Embodiment 13 of the variable magnification imaging optical system of the present invention. [Figure 125] This is a diagram of the lateral aberration at the wide-angle end when the variable magnification imaging optical system of the present invention is in focus at infinity, according to Embodiment 13. [Figure 126] This is a lateral aberration diagram at infinity focus according to Embodiment 13 of the variable magnification imaging optical system of the present invention. [Figure 127] This is a lateral aberration diagram at infinity focus at the telephoto end according to Embodiment 13 of the variable magnification imaging optical system of the present invention. [Figure 128] This is a lateral aberration diagram of the wide-angle end at an object distance of 2.5m when the variable magnification imaging optical system of the present invention is in focus, according to Embodiment 13. [Figure 129] This is a lateral aberration diagram for an intermediate focal length at an object distance of 2.5m, according to Embodiment 13 of the variable magnification imaging optical system of the present invention. [Figure 130] This is a lateral aberration diagram of Embodiment 13 of the variable magnification imaging optical system of the present invention when the object distance at the telephoto end is 2.5m and in focus. [Modes for carrying out the invention]

[0019] The following describes a variable-magnification imaging optical system according to an embodiment of the present invention. Note that the following description of the embodiments illustrates an example of the optical system of the present invention, and the present invention is not limited to these embodiments without departing from its spirit. Furthermore, the object side will be described first, and the image side second.

[0020] Furthermore, in the following description of the examples, the refractive indices of the materials for the g-line (wavelength 435.8 nm), F-line (486.1 nm), d-line (587.6 nm), and C-line (656.3 nm) are Ng, NF, Nd, and NC, respectively. Then, the Abbe number νd, partial dispersion ratio PgF, and anomalous partial dispersion ΔPgF are defined as follows: νd = (Nd-1) / (NF-NC) PgF = (Ng-NF) / (NF-NC) ΔPgF = PgF-0.64833+0.00180×νd It is expressed as follows.

[0021] In this application, when counting the number of lenses, unless otherwise specified, a single lens is counted as one lens, and in the case of a cemented lens, each of the single lenses that make up the cemented lens is counted as one lens. For example, a cemented lens consisting of a convex lens and a concave lens is counted as two lenses.

[0022] In this application, lens groups are defined by the planes whose spacing on the optical axis changes due to magnification or focusing. Therefore, when the aperture diaphragm S moves independently due to magnification or focusing, the aperture diaphragm S is treated as a single lens group.

[0023] In this application, there is a description of ray heights such as on-axis marginal ray height and off-axis principal ray height. However, these basically refer to the distance from the optical axis, so the concept of positive and negative does not arise, and the optical axis is treated as 0, with the direction away from it being treated as positive. However, regarding the off-axis principal rays in conditional equations (4) and (5), a positive and negative relationship arises because it deals with the relationship between the image height of the off-axis principal ray and the height of the off-axis principal ray passing through the second lens group G2.

[0024] In super-telephoto zoom lenses like the one of the present invention, suppressing chromatic aberration is an essential element for achieving high performance. There are two types of chromatic aberration: axial chromatic aberration and lateral chromatic aberration. To suppress both of these across the entire zoom range, it is crucial to select appropriate glass materials according to the changes in power distribution.

[0025] In general, the chromatic aberration of an optical system composed of thin lenses is given by the sum of the aberrations of each lens as shown in (Reference Equation 1) below, and can be considered as follows.

[0026] When a lens with positive refractive power is placed on the object side of the aperture, the peripheral light beam passing through the lens will pass through the quadrant opposite to the image formation position. In the case of typical optical glass, due to the dispersion characteristics, longer wavelengths will be imaged at a lower image height, and the C line will be observed as underexposure chromatic aberration. Similarly, when a lens with negative refractive power is placed on the object side of the aperture, the opposite phenomenon occurs. Also, when a lens is placed on the image side of the aperture, the peripheral light beam passing through the lens and the image formation position will pass through the same quadrant, resulting in the opposite phenomenon to when the lens is placed on the object side of the aperture. (Reference formula 1)Σ(h·hb·φ / ν) h: On-axis marginal ray height hb: Off-axis principal ray height φ: Refractive force ν: Abbe number Furthermore, the on-axial marginal ray is defined as the ray included in the on-axial beam that passes through the aperture at its maximum height from the optical axis, and the principal ray is defined as the ray that passes through the point where the aperture plane and the optical axis intersect.

[0027] Similarly, the axial chromatic aberration of an optical system composed of thin lenses is given by the following (Reference Equation 2) as the sum of the values ​​of each lens, and can be considered as follows. (Reference formula 2)Σ(h·h·φ / ν) h: On-axis marginal ray height φ: Refractive force ν: Abbe number Furthermore, the on-axial marginal ray is defined as the ray included in the on-axial light beam that passes through the aperture at its maximum height from the optical axis. Focusing on the axial marginal ray height in Reference Equation 2, lenses in which the axial marginal ray passes at a higher position relative to the effective diameter exhibit greater axial chromatic aberration, while lenses in which the axial marginal ray passes at a lower position exhibit less axial chromatic aberration. Therefore, to suppress axial and lateral chromatic aberration throughout the entire zoom range, it is necessary to appropriately select the glass material in accordance with the changes in the ray heights of the axial marginal ray and the off-axis principal ray during zooming.

[0028] In a variable-magnification imaging optical system like the present invention, where the first lens group G1 has positive refractive power and extends significantly as the magnification changes from the wide-angle end to the telephoto end, widening the gap with the aperture diaphragm S, chromatic aberration occurs in many cases where the C line is overexposed at the wide-angle end and underexposed at the telephoto end, and this fluctuates with magnification. Therefore, if the g line and C line are combined in a way that collects them, and the difference in imaging magnification with other wavelengths is large, a secondary spectrum appears, resulting in undesirable color fringing such as reddish-purple around the outline of the subject.

[0029] This phenomenon occurs because, as the magnification changes from wide-angle to telephoto, the first lens group G1 extends, widening the distance from the aperture diaphragm S, and the second lens group G2 and subsequent lens groups move closer to the aperture diaphragm S. This change in power distribution causes a significant alteration in the correction effect of chromatic aberration in the second lens group G2 and subsequent lens groups, in addition to the change in chromatic aberration occurring in the first lens group G1. The further the distance from the aperture diaphragm S, the higher the off-axis principal rays pass, further away from the optical axis, and as shown in (Reference Equation 1), the change in ray height leads to a change in chromatic aberration.

[0030] Furthermore, to correct secondary spectra, it is effective to appropriately arrange glass materials with anomalous dispersion properties in accordance with the change in the correction effect of magnification chromatic aberration due to the change in magnification. For example, in cases where secondary spectra are problematic between the g-line and the d-line after the g-line and the c-line have been collected, if one tries to collect the d-line and the c-line forcibly, the g-line will be undercorrected. However, by using glass materials with anomalous dispersion properties, it becomes possible to compensate for the undercorrection of the g-line, and as a result, secondary spectra can be reduced. Below, an embodiment of the present invention that suppresses secondary spectra across the entire zoom range and effectively corrects magnification chromatic aberration will be described, focusing on the correction of the g-line.

[0031] As can be seen from the numerical examples and the configuration diagrams of each example, the variable magnification imaging optical system of the present invention consists of, in order from the object side, a first lens group G1 having positive refractive power, a second lens group G2 having positive refractive power, a third lens group G3 having negative refractive power, a first intermediate group GM1 consisting of one or more lens groups including an aperture diaphragm S, a second intermediate group GM2, and a subsequent group GR consisting of one or more lens groups. During magnification or focusing, the distance between adjacent lens groups changes. When magnifying from the wide-angle end to the telephoto end, the first lens group G1 moves toward the object, the second lens group G2 is fixed relative to the image plane or moves toward the image, the distance between the first lens group G1 and the second lens group G2 increases, and the distance between the second lens group G2 and the third lens group G3 decreases. When focusing from an object at infinity to an object at close range, the second intermediate group GM2 moves along the optical axis.

[0032] The first lens group G1, which has positive refractive power, the second lens group G2, which also has positive refractive power, and the third lens group G3, which has negative refractive power, all contribute to the main magnification effect of the variable-magnification imaging optical system when the magnification changes from the wide-angle end to the telephoto end. The first lens group G1 moves toward the object, the second lens group G2 is fixed relative to the image plane or moves toward the image, the distance between the first lens group G1 and the second lens group G2 increases, and the distance between the second lens group G2 and the third lens group G3 decreases.

[0033] The second lens group G2, which has positive refractive power, remains fixed to the image plane or moves toward the image side when the magnification changes from the wide-angle end to the telephoto end, and the lens group including the aperture diaphragm S moves toward the object side. As the distance to the aperture diaphragm S decreases when the magnification changes from the wide-angle end to the telephoto end, the off-axis principal rays, which passed at a high position at the wide-angle end, pass at a lower position at the telephoto end, and the correction effect of the second lens group G2 on chromatic aberration is large at the wide-angle end and small at the telephoto end.

[0034] On the other hand, the first lens group G1 moves towards the object at the telephoto end, and the distance between it and the second lens group G2 increases. As a result, the on-axial marginal ray height at infinity focus is lower for the second lens group G2 than for the first lens group G1, and for the second lens group G2, the on-axial marginal ray height at the telephoto end becomes lower than the off-axis principal ray height at the wide-angle end where the angle of view is at its maximum.

[0035] Furthermore, by using glass materials with positive anomalous dispersion in the concave lens and negative anomalous dispersion in the convex lens of the second lens group G2, it becomes possible to correct the g-line in the underexposure direction at the wide-angle end, making it easier to correct chromatic aberration.

[0036] The first intermediate group GM1, which consists of one or more lens groups and includes an aperture diaphragm S, has the effect of converging the light beam diverged by the third lens group G3, and controls the height of the light rays incident on the second intermediate group GM2 to an appropriate height. This contributes to the weight reduction of the second intermediate group GM2 and also plays a role in image plane compensation during zooming.

[0037] The second intermediate group GM2 moves along the optical axis when focusing from an object at infinity to an object at a close distance, correcting for shifts in the image formation position when the object distance changes.

[0038] The subsequent GR group, consisting of one or more lens groups, is responsible for image plane compensation and corrects chromatic aberration, which becomes more pronounced at the telephoto end. By using glass with positive anomalous dispersion for the concave lens and glass with negative anomalous dispersion for the convex lens of the subsequent GR group, an effect is generated that corrects the g-line in the overexposure direction, making it possible to correct chromatic aberration at the telephoto end. Furthermore, in the subsequent GR group, on-axial marginal rays pass through at a lower ray height relative to off-axial principal rays, minimizing the deterioration of on-axial chromatic aberration while having the characteristic of increasing the correction effect of chromatic aberration at higher image heights.

[0039] On the other hand, if the subsequent GR group uses glass material with positive anomalous dispersion for the concave lens and glass material with negative anomalous dispersion for the convex lens to correct chromatic aberration at the telephoto end, the g-line will be overcorrected at the wide-angle end, worsening chromatic aberration. However, by offsetting this worsening of chromatic aberration at the wide-angle end with the correction effect of the second lens group G2, which has a large effect of correcting the g-line in the under-correction direction at the wide-angle end, it becomes possible to correct chromatic aberration well across the entire range from the wide-angle end to the telephoto end.

[0040] In the variable magnification imaging optical system of the present invention, it is desirable to satisfy the following condition (1) in order to achieve both a reduction in the overall length of the optical system and improved performance. (1) 0.2 <f1 / fT<1.0 f1: Focal length of the first lens group G1 fT: Total focal length of the system at the infinity telephoto end

[0041] The conditional equation (1) that the variable magnification imaging optical system of the present invention must satisfy defines the ratio of the total focal length of the system to the focal length of the first lens group G1 at the infinity telephoto end, and indicates a desirable range in terms of shortening the overall length of the optical system and reducing the weight of the lens barrel.

[0042] If the upper limit of condition (1) is exceeded and the focal length of the first lens group G1 becomes longer than the total focal length of the system at the infinity telephoto end, the overall optical length at the telephoto end becomes too long, increasing the amount of movement of the first lens group G1 due to zooming, making the movement mechanism more complex and resulting in a larger lens barrel.

[0043] When the lower limit of condition (1) is exceeded, and the focal length of the first lens group G1 becomes shorter than the focal length of the entire system at the infinity telephoto end, the image magnification of the combined system from the second lens group G2 onwards at the telephoto end becomes too high, making it difficult to correct aberrations such as axial chromatic aberration at the telephoto end.

[0044] Furthermore, regarding condition (1), it is preferable to specify a lower limit of 0.3 and an upper limit of 0.7 to make the aforementioned effect more certain.

[0045] Furthermore, in order to achieve both a reduction in the overall length of the optical system and improved performance, it is desirable that the following condition (2) be satisfied. (2) 0.10 <f2 / fT<1.40 f2: Focal length of the second lens group G2. fT: Total focal length of the system at the infinity telephoto end

[0046] The conditional equation (2) that the variable magnification imaging optical system of the present invention must satisfy defines the ratio of the total focal length of the system to the focal length of the second lens group G2 at the infinity telephoto end, and indicates a desirable range in terms of shortening the overall length of the optical system and reducing the weight of the lens barrel.

[0047] If the upper limit of condition (2) is exceeded and the focal length of the second lens group G2 becomes longer than the total focal length of the system at the infinity telephoto end, the combined positive refractive power of the first lens group G1 and the second lens group G2 decreases, making it difficult to shorten the overall length of the optical system. Furthermore, if the insufficient combined refractive power of the first lens group G1 and the second lens group G2 is compensated for by strengthening the power of the first lens group G1, it becomes difficult to use low refractive index, low dispersion glass such as fluorite for the convex lens of the first lens group G1, which plays an important role in correcting axial chromatic aberration, making it difficult to improve performance.

[0048] When the lower limit of condition (2) is exceeded and the focal length of the second lens group G2 becomes small relative to the overall focal length of the system at infinity telephoto, the power of the second lens group G2 increases, making it difficult to suppress astigmatism, especially at the wide-angle end where the off-axis principal rays pass at a high position, and thus making it difficult to improve performance.

[0049] Furthermore, regarding condition (2), it is preferable to specify a lower limit of 0.20 and an upper limit of 1.10 to make the aforementioned effect more certain.

[0050] Furthermore, in the variable-magnification imaging optical system of the present invention, it is desirable to satisfy the following condition (3) in order to effectively correct axial chromatic aberration and lateral chromatic aberration throughout the entire zoom range. (3) 0.2 <g2AXhW / g2AXhT<1.5 g2AXhW: Height of the axial marginal rays on the leading surface of the second lens group G2 at the wide-angle end at infinity with the aperture wide open. g2AXhT: Height of the axial marginal rays on the leading surface of the second lens group G2 at the infinity telephoto end with the aperture wide open. On-axial marginal rays are defined as the rays included in the on-axial beam that pass through the aperture at the maximum height from the optical axis.

[0051] The conditional equation (3) that the variable magnification imaging optical system of the present invention must satisfy defines the ratio of the height of the axial marginal rays on the leading surface of the second lens group G2 at the wide-angle end at infinity with the aperture wide open, to the height of the axial marginal rays on the leading surface of the second lens group G2 at the telephoto end at infinity with the aperture wide open.

[0052] As mentioned above, in the second lens group G2, it is desirable to use glass material with positive anomalous dispersion for the concave lens in order to correct the g-line in the underexposure direction at the wide-angle end and suppress lateral chromatic aberration. On the other hand, if glass material with a large ΔPgF and strong positive anomalous dispersion is used for the concave lens of the second lens group G2, the image formation position of the g-line and C-line in the axial light beam shifts towards the image side, which acts in the direction of increasing the secondary spectrum and works unfavorably for correcting axial chromatic aberration. Furthermore, axial chromatic aberration becomes more noticeable as the angle of view narrows at the telephoto end, so in order to improve image quality, the deterioration of axial chromatic aberration must also be suppressed. Therefore, in order to use glass materials with strong positive anomalous dispersion, which are advantageous for correcting chromatic aberration at the wide-angle end, while preventing deterioration of axial chromatic aberration, it is necessary to control the axial marginal ray height to be small relative to the effective diameter of the second lens group G2 (in the case of the second lens group G2, the effective diameter is determined by the height of the off-axis light beam at the maximum angle of view at the wide-angle end), and controlling the axial marginal ray height is particularly important at the telephoto end.

[0053] When the upper limit of condition (3) is exceeded, and the ratio of the height of the axial marginal rays on the leading surface of the second lens group G2 at the wide-angle end at infinity with the aperture wide open to the height of the axial marginal rays on the leading surface of the second lens group G2 at the telephoto end at infinity with the aperture wide open becomes large, the height of the axial marginal rays on the leading surface of the second lens group G2 at the wide-angle end at infinity with the aperture wide open becomes too large, making it difficult to correct axial chromatic aberration on the wide-angle side. At the same time, it becomes necessary to increase the power of the first lens group G1 to lower the height of the axial marginal rays on the telephoto side, which worsens various aberrations and makes it difficult to improve performance.

[0054] When the lower limit of condition (3) is exceeded, and the ratio of the height of the axial marginal rays on the leading surface of the second lens group G2 at the wide-angle end at infinity with the aperture wide open to the height of the axial marginal rays on the leading surface of the second lens group G2 at the telephoto end at infinity with the aperture wide open becomes small, the height of the axial marginal rays on the leading surface of the second lens group G2 at the telephoto end at infinity with the aperture wide open becomes large, making it difficult to correct axial chromatic aberration and hindering high performance.

[0055] Furthermore, regarding condition (3), it is preferable to specify a lower limit of 0.3 and an upper limit of 1.3 to make the aforementioned effect more certain.

[0056] Furthermore, in the variable magnification imaging optical system of the present invention, the second lens group G2, which exhibits a large change in the ray height of the off-axis principal rays when zooming from the wide-angle end to the telephoto end, plays an important role in effectively correcting the chromatic aberration of magnification that fluctuates with zooming. To improve the performance of the optical system, it is desirable to satisfy the following conditions (4) and (5). (4)-1.8<(g2OAhW / Wih)-(g2hrT / Tih)<-0.3 (5) 0.6 < |g2OAhW / g2AXhT| < 2.5 With: Image height of the off-axis principal ray at the widest angle of view at infinity. Tih: Image height of the off-axis principal ray at the maximum field of view at the telephoto end of infinity. g2OAhW: Height of the off-axis principal ray at the front surface of the second lens group G2 at the wide-angle end of infinity. g2OAhT: Height of the off-axis principal ray at the front surface of the second lens group G2 at the infinity telephoto end, where the angle of view is at its maximum. g2AXhT: Height of the axial marginal rays on the leading surface of the second lens group G2 at the infinity telephoto end with the aperture wide open. Furthermore, the light ray g2OAhW corresponds to Wih, and the light ray g2OAhT corresponds to Tih. The second lens group G2 is located on the object side of the aperture diaphragm S, and the quadrant through which the light rays pass is reversed, so g2OAhW and g2OAhT have opposite signs for Wih and Tih. Furthermore, the on-axial marginal ray is defined as the ray included in the on-axial beam that passes through the aperture at its maximum height from the optical axis.

[0057] Conditional equation (4) specifies a desirable range for the difference between the ratio of the height of the off-axis principal ray at the maximum angle of view on the leading surface of the second lens group G2 at the wide-angle end and the image height of the off-axis principal ray at the maximum angle of view at the wide-angle end, and the ratio of the height of the off-axis principal ray at the maximum angle of view on the leading surface of the second lens group G2 at the telephoto end and the image height of the off-axis principal ray at the maximum angle of view at the telephoto end. When this difference approaches 0 and becomes large, it means that the change in the off-axis principal ray in the second lens group G2 is small when zooming from the wide-angle end to the telephoto end. Conversely, when it moves away from 0 and becomes small, it means that the change in the off-axis principal ray in the second lens group G2 is large when zooming from the wide-angle end to the telephoto end.

[0058] When the upper limit of condition (4) is exceeded, and the difference between the ratio of the height of the off-axis principal rays at the maximum angle of view on the leading surface of the second lens group G2 at the wide-angle end and the image height of the off-axis principal rays at the maximum angle of view at the wide-angle end, and the ratio of the height of the off-axis principal rays at the maximum angle of view on the leading surface of the second lens group G2 at the telephoto end at infinity, increases as it approaches 0, the change in the off-axis principal rays in the second lens group G2 becomes smaller when zooming from the wide-angle end at infinity to the telephoto end at infinity, the correction effect of chromatic aberration decreases, and chromatic aberration cannot be sufficiently corrected at either the wide-angle end, the telephoto end, or both, which is undesirable.

[0059] When the lower limit of condition (4) is exceeded, and the difference between the ratio of the height of the off-axis principal rays at the maximum angle of view on the leading surface of the second lens group G2 at the wide-angle end and the image height of the off-axis principal rays at the maximum angle of view at the wide-angle end, and the ratio of the height of the off-axis principal rays at the maximum angle of view on the leading surface of the second lens group G2 at the telephoto end and the image height of the off-axis principal rays at the telephoto end, decreases in the direction away from 0, the change in the off-axis principal rays in the second lens group G2 becomes too large when zooming from the wide-angle end to the telephoto end, making it difficult to correct astigmatism and field curvature, which is undesirable.

[0060] Furthermore, regarding conditional equation (4), it is preferable to specify a lower limit of -1.5 and an upper limit of -0.4 to make the aforementioned effect more certain.

[0061] Conditional equation (5) defines the absolute value of the ratio between the height of the off-axis principal ray at the maximum angle of view on the leading surface of the second lens group G2 at the wide-angle end at infinity and the height of the on-axis marginal ray at the leading surface of the second lens group G2 at the telephoto end at infinity with the aperture wide open. Note that the off-axis principal ray defined in conditional equation (5) refers to the off-axis principal ray at the maximum angle of view at the wide-angle end at infinity, as defined in conditional equation (4).

[0062] When the upper limit of condition (5) is exceeded, and the absolute value of the ratio between the height of the off-axis principal rays at the maximum angle of view on the leading surface of the second lens group G2 at the wide-angle end at infinity and the height of the on-axis marginal rays on the leading surface of the second lens group G2 at the telephoto end at infinity with the aperture wide open becomes large, it becomes necessary to increase the power of the first lens group G1 in order to lower the height of the on-axis marginal rays on the telephoto side, which leads to a deterioration of various aberrations and makes it difficult to improve performance.

[0063] When the lower limit of condition (5) is exceeded, and the absolute value of the ratio between the height of the off-axis principal ray at the maximum angle of view on the leading surface of the second lens group G2 at the wide-angle end at infinity and the height of the on-axis marginal ray at the leading surface of the second lens group G2 at the telephoto end at infinity with the aperture wide open becomes small, the height of the on-axis marginal ray does not decrease sufficiently on the telephoto side, increasing the on-axis chromatic aberration generated in the second lens group G2 and making it difficult to achieve high performance. Also, the absolute value of the height of the off-axis principal ray at the maximum angle of view at the wide-angle end at infinity becomes small (simply put, without considering the concept of signs, this is equivalent to the height of the off-axis principal ray from the optical axis becoming lower), making it difficult to correct lateral chromatic aberration on the wide-angle side and making it difficult to achieve high performance.

[0064] Furthermore, regarding condition (5), it is preferable to specify a lower limit of 0.8 and an upper limit of 1.9 to make the aforementioned effect more certain.

[0065] Furthermore, in the variable magnification imaging optical system of the present invention, conditional equations (6) to (9) define the relationship between the second lens group G2 and the lens groups before and after it, which is necessary for the second lens group G2 to effectively correct the chromatic aberration of magnification that changes with zooming from the wide-angle end to the telephoto end.

[0066] In the variable magnification imaging optical system of the present invention, it is desirable that the second lens group G2 satisfies the following condition (6) in order to effectively correct the chromatic aberration of magnification that varies with zooming from the wide-angle end to the telephoto end. (6) 0.005 <DG1G2W / DG1G2T<0.400 DG1G2W: Distance on the optical axis between the first lens group G1 and the second lens group G2 at the wide-angle end of infinity. DG1G2T: Distance on the optical axis between the first lens group G1 and the second lens group G2 at the infinity telephoto end.

[0067] Conditional equation (6) specifies the ratio of the distance between the first lens group G1 and the second lens group G2 on the optical axis at the wide-angle end and the telephoto end at infinity. It is desirable that the second lens group G2 has a corrective effect on chromatic aberration, correcting the g-line in the under-angle direction at the wide-angle end. To enhance this effect, it is desirable that the off-axis principal ray height passes through a higher position at the wide-angle end, and as mentioned above, it is desirable that the on-axis marginal ray height passes through a lower position at the telephoto end. Therefore, it is desirable that the distance between the first lens group G1 and the second lens group G2 be small at the wide-angle end and large at the telephoto end.

[0068] If the upper limit of condition (6) is exceeded, and the ratio of the distance between the first lens group G1 and the second lens group G2 on the optical axis at the wide-angle end and the telephoto end at infinity becomes large, the distance between the first lens group G1 and the second lens group G2 at the telephoto end becomes small, and the axial marginal ray height does not decrease sufficiently at the telephoto end, leading to a deterioration of axial chromatic aberration, which is undesirable. Also, if the distance between the first lens group G1 and the second lens group G2 becomes large at the wide-angle end, it will have the effect of increasing the overall length of the product, which is also undesirable.

[0069] If the lower limit of condition (6) is exceeded, and the ratio of the distance between the first lens group G1 and the second lens group G2 on the optical axis at the infinity wide-angle end and the infinity telephoto end becomes small, the change in the off-axis principal rays in the second lens group G2 becomes too large when zooming from the infinity wide-angle end to the infinity telephoto end, making it difficult to correct astigmatism and field curvature, which is undesirable.

[0070] Furthermore, regarding conditional equation (6), it is preferable to specify a lower limit of 0.009 and an upper limit of 0.200 to make the aforementioned effect more reliable.

[0071] Furthermore, in the variable magnification imaging optical system of the present invention, it is desirable that the second lens group G2 satisfies the following condition (7) in order to effectively correct the chromatic aberration of magnification that varies with zooming from the wide-angle end to the telephoto end. (7) 1.00 <DG2G3W / DG2G3T<80.00 DG2G3W: Distance on the optical axis between the second lens group G2 and the third lens group G3 at the wide-angle end of infinity. DG2G3T: Distance on the optical axis between the second lens group G2 and the third lens group G3 at the infinity telephoto end.

[0072] Conditional equation (7) specifies the ratio of the distance between the second lens group G2 and the third lens group G3 on the optical axis at the wide-angle end and the telephoto end at infinity. It is desirable that the second lens group G2 has a corrective effect on chromatic aberration, correcting the g-line in the under-angle direction at the wide-angle end. To enhance this effect, it is desirable that the off-axis principal ray height passes through a higher position at the wide-angle end, and as mentioned above, it is desirable that the on-axis marginal ray height passes through a lower position at the telephoto end. Therefore, it is desirable that the distance between the second lens group G2 and the third lens group G3 be large at the wide-angle end and small at the telephoto end.

[0073] If the upper limit of condition (7) is exceeded, and the ratio of the distance between the second lens group G2 and the third lens group G3 on the optical axis at the infinity wide-angle end and the infinity telephoto end becomes large, the change in the off-axis principal ray in the second lens group G2 becomes too large when zooming from the infinity wide-angle end to the infinity telephoto end, making it difficult to correct astigmatism and field curvature, which is undesirable.

[0074] If the lower limit of condition (7) is exceeded and the ratio of the distance between the second lens group G2 and the third lens group G3 on the optical axis at the wide-angle end and the telephoto end at infinity becomes small, the distance between the second lens group G2 and the third lens group G3 on the optical axis at the wide-angle end becomes small, preventing the off-axis principal ray from passing through a sufficiently high position at the wide-angle end. This reduces the chromatic aberration correction effect that corrects the g-line in the underexposed direction, which is undesirable. Also, if the distance between the second lens group G2 and the third lens group G3 on the optical axis becomes large at the telephoto end, the on-axial marginal ray height passing through the second lens group G2 does not decrease sufficiently at the telephoto end, leading to a deterioration of on-axial chromatic aberration, which is undesirable.

[0075] Furthermore, regarding conditional equation (7), it is preferable to specify a lower limit of 1.10 and an upper limit of 40.00 to make the aforementioned effect more certain.

[0076] Furthermore, in the variable magnification imaging optical system of the present invention, it is desirable that the second lens group G2 satisfies the following condition (8) in order to effectively correct the chromatic aberration of magnification that varies with zooming from the wide-angle end to the telephoto end. (8) 0.01 <DG1G2W / DG2G3W<2.00 DG1G2W: Distance on the optical axis between the first lens group G1 and the second lens group G2 at the wide-angle end of infinity. DG2G3W: Distance on the optical axis between the second lens group G2 and the third lens group G3 at the wide-angle end of infinity.

[0077] Conditional equation (8) specifies the ratio of the distance on the optical axis between the first lens group G1 and the second lens group G2, and the distance on the optical axis between the second lens group G2 and the third lens group G3, at the wide-angle end at infinity. It is desirable that the second lens group G2 has a corrective effect on lateral chromatic aberration, correcting the g-line in the under-angle direction at the wide-angle end. To enhance this effect, it is desirable that the off-axis principal ray height passes through a higher position at the wide-angle end, and as mentioned above, it is desirable that the on-axis marginal ray height passes through a lower position at the telephoto end. Therefore, at the wide-angle end at infinity, the closer the second lens group G2 is to the first lens group G1, the shorter the distance to the first lens group G1, and the wider the distance to the third lens group G3, the higher the off-axis principal ray height passing through the second lens group G2, and thus the more effectively lateral chromatic aberration is corrected.

[0078] When the upper limit of condition (8) is exceeded, and the ratio of the distance between the first lens group G1 and the second lens group G2 on the optical axis to the distance between the second lens group G2 and the third lens group G3 on the optical axis at the wide-angle end at infinity becomes large, the second lens group G2 comes too close to the third lens group G3 at the wide-angle end at infinity, causing the off-axis principal rays passing through the second lens group G2 to pass at a low position, making effective correction of chromatic aberration difficult and undesirable.

[0079] When the lower limit of condition (8) is exceeded, and the ratio of the distance between the first lens group G1 and the second lens group G2 on the optical axis to the distance between the second lens group G2 and the third lens group G3 on the optical axis at the wide-angle end at infinity becomes small, the second lens group G2 comes too close to the first lens group G1 at the wide-angle end at infinity, causing the off-axis principal rays passing through the second lens group G2 to pass at a higher position. This increases the effective diameter of the second lens group G2, increases the weight of the optical system, and is undesirable.

[0080] Furthermore, regarding condition (8), it is preferable to specify a lower limit of 0.02 and an upper limit of 1.50 to make the aforementioned effect more certain.

[0081] Furthermore, in the variable magnification imaging optical system of the present invention, it is desirable that the second lens group G2 satisfies the following condition (9) in order to effectively correct the chromatic aberration of magnification that changes with zooming from the wide-angle end to the telephoto end. (9) 2.0 <DG1G2T / DG2G3T<200.0 DG1G2T: Distance on the optical axis between the first lens group G1 and the second lens group G2 at the infinity telephoto end. DG2G3T: Distance on the optical axis between the second lens group G2 and the third lens group G3 at the infinity telephoto end.

[0082] Conditional equation (9) specifies the ratio of the distance on the optical axis between the first lens group G1 and the second lens group G2, and the distance on the optical axis between the second lens group G2 and the third lens group G3 at the infinity telephoto end. It is desirable that the second lens group G2 has a corrective effect on lateral chromatic aberration, correcting the g-line in the under-angle direction at the wide-angle end. To enhance this effect, it is desirable that the off-axis principal ray passes through a higher position at the wide-angle end, and, as mentioned above, that the on-axial marginal ray passes through a lower position at the telephoto end. Therefore, at the infinity telephoto end, it is possible to suppress the deterioration of on-axial chromatic aberration by having the second lens group G2 closer to the third lens group G3, increasing the distance between it and the first lens group G1, and decreasing the distance between it and the third lens group G3, because the on-axial marginal ray passes through a lower position.

[0083] If the upper limit of condition (9) is exceeded, and the ratio of the distance between the first lens group G1 and the second lens group G2 on the optical axis to the distance between the second lens group G2 and the third lens group G3 on the optical axis at the infinity telephoto end becomes large, the distance between the first lens group G1 and the second lens group G2 on the optical axis at the infinity telephoto end becomes too large, causing the optical system to become bloated, which is undesirable.

[0084] When the lower limit of condition (9) is exceeded, and the ratio of the distance between the first lens group G1 and the second lens group G2 on the optical axis to the distance between the second lens group G2 and the third lens group G3 on the optical axis at the infinity telephoto end becomes small, the distance between the second lens group G2 and the third lens group G3 on the optical axis at the infinity telephoto end does not decrease, and the axial marginal rays pass through a higher point, which leads to a deterioration of axial chromatic aberration and is undesirable.

[0085] Furthermore, regarding conditional equation (9), it is possible to more reliably achieve the aforementioned effect by preferably setting the lower limit to 3.0 and the upper limit to 150.0, and more preferably setting the lower limit to 4.0 and the upper limit to 120.0.

[0086] Furthermore, in the variable magnification imaging optical system of the present invention, the second lens group G2, which experiences a large change in the ray height of the off-axis principal rays when zooming from the wide-angle end to the telephoto end, plays an important role in effectively correcting the chromatic aberration of magnification that fluctuates with zooming, and it is desirable that at least one of these lenses be a concave lens. Note that the concave lens referred to here may be a lens arranged independently or a concave lens arranged as part of a cemented lens.

[0087] For the second lens group G2, it is important to use glass material that corrects the g-line in the underexposure direction at the wide-angle end in order to effectively correct chromatic aberration at the wide-angle end. For convex lenses, it is desirable to select glass material with negative anomalous dispersion, and for concave lenses, it is desirable to select glass material with positive anomalous dispersion. Examples of glass material with negative anomalous dispersion from HOYA include high refractive index, low dispersion glass material such as TAFD30 and Kurzflint-type glass material such as E-ADF10. Examples of glass material with positive anomalous dispersion from HOYA include low refractive index, low dispersion glass material such as FCD1 and high refractive index, high dispersion glass material such as E-FDS1-W, and high dispersion glass material such as J-SFH4 from Hikari Glass Co., Ltd. Comparing the two, glass materials with positive anomalous dispersion offer a greater variety of glass types and greater freedom in glass material selection, as well as greater anomalous dispersion. Therefore, it is desirable to include at least one concave lens in the second lens group G2, and it is desirable to use a glass material with high positive anomalous dispersion for that concave lens.

[0088] Furthermore, in the variable magnification imaging optical system of the present invention, the second lens group G2, which experiences a large change in the ray height of the off-axis principal rays when zooming from the wide-angle end to the telephoto end, plays an important role in effectively correcting the chromatic aberration of magnification that fluctuates with zooming. For this purpose, it is desirable to include at least one concave lens that satisfies the following condition (10). (10)ΔPgFLg2>0.0090 ΔPgFLg2: The anomalous dispersion of the concave lens with the greatest anomalous dispersion among the concave lenses included in the second lens group G2.

[0089] Conditional equation (10) specifies the desirable range of anomalous dispersion for one or more concave lenses included in the second lens group G2. Note that the concave lenses referred to here may be individual lenses or concave lenses that are part of a cemented lens.

[0090] As mentioned above, the second lens group G2 moves toward the image plane when zooming from the wide-angle end to the telephoto end, and the off-axis principal rays passing through the second lens group G2 pass at a higher position at the wide-angle end and a lower position at the telephoto end. In order to suppress chromatic aberration across the entire zoom range and improve performance, the second lens group G2 needs to correct the g-line to be more underexposed at the wide-angle end. Therefore, a large ΔPgF and strong positive anomalous dispersion are advantageous for correcting the g-line.

[0091] When the anomalous dispersion decreases beyond the lower limit of condition equation (10), the effect of correcting the underexposure of the g line at the wide-angle end decreases, making it difficult to suppress chromatic aberration across the entire zoom range and improve performance.

[0092] Furthermore, regarding conditional equation (10), the aforementioned effect can be made more certain by specifying the lower limit as preferably 0.0095, more preferably 0.0100, and even more preferably 0.0150.

[0093] Furthermore, in order to achieve both a reduction in the overall length of the optical system and improved performance, it is desirable that the following condition (11) be satisfied. (11) 1.0 <f1 / fW<5.0 f1: Focal length of the first lens group G1 fW: Total focal length of the system at the wide-angle end at infinity

[0094] Conditional equation (11) defines the ratio of the total focal length of the system at the wide-angle end at infinity to the focal length of the first lens group G1, and indicates a desirable range for achieving both a reduction in the overall length of the optical system and improved performance.

[0095] If the focal length of the first lens group G1 exceeds the upper limit of condition (11) and becomes larger than the total focal length of the system at the wide-angle end at infinity, the refractive power of the first lens group G1 becomes insufficient, making it difficult to shorten the overall length of the optical system, which is undesirable.

[0096] If the focal length of the first lens group G1 exceeds the lower limit of condition (11) and becomes smaller than the total focal length of the system at the wide-angle end at infinity, the refractive power of the first lens group G1 becomes too strong, making it difficult to correct various aberrations such as spherical aberration and astigmatism, which hinders high performance and is undesirable.

[0097] Furthermore, regarding conditional equation (11), it is preferable to set the lower limit to 1.3 and the upper limit to 4.0 to make the aforementioned effect more reliable.

[0098] Furthermore, in order to achieve both a reduction in the overall length of the optical system and improved performance, it is desirable that the following condition (12) be satisfied. (12) 0.5 <f2 / fW<8.5 f2: Focal length of the second lens group G2. fW: Total focal length of the system at the wide-angle end at infinity

[0099] Conditional equation (12) defines the ratio of the total focal length of the system at the wide-angle end at infinity to the focal length of the second lens group G2, and indicates a desirable range for achieving both a reduction in the overall length of the optical system and improved performance.

[0100] If the focal length of the second lens group G1 exceeds the upper limit of condition (12) and becomes larger than the total focal length of the system at the wide-angle end at infinity, the refractive power of the second lens group G2 becomes insufficient, making it difficult to shorten the overall length of the optical system. At the same time, it becomes necessary to compensate for the insufficient refractive power by strengthening the refractive power of the first lens group G1, which increases the aberrations generated in the first lens group G1, making it difficult to improve performance and is undesirable.

[0101] If the focal length of the second lens group G2 exceeds the lower limit of condition (12) and becomes smaller than the total focal length of the system at the wide-angle end at infinity, the refractive power of the second lens group G2 becomes too strong, resulting in increased coma and astigmatism in the second lens group, making it difficult to achieve high performance, which is undesirable.

[0102] Furthermore, regarding conditional equation (12), it is preferable to set the lower limit to 0.7 and the upper limit to 7.5 to make the aforementioned effect more reliable.

[0103] Furthermore, in the variable magnification imaging optical system of the present invention, it is desirable to satisfy the following condition (13) in order to achieve effective correction of chromatic aberration across the entire zoom range. (13) 1.2 <DG2Sw / DG2St<5.0 DG2Sw: Distance from the top of the object's side to the aperture of the lens closest to the object in the second lens group G2 at the wide-angle end. DG2St: Distance from the top of the object's side to the aperture of the lens closest to the object in the second lens group G2 at the telephoto end.

[0104] The conditional equation (13) that the variable-magnification imaging optical system of the present invention must satisfy defines a desirable range for the ratio of the distance from the top of the object side of the object-side lens of the second lens group G2 to the aperture diaphragm S at the wide-angle end and the telephoto end. As described above, when the variable-magnification imaging optical system of the present invention changes magnification from the wide-angle end to the telephoto end, the second lens group G2 moves toward the image side, and the distance between it and the third lens group G3 decreases, so the distance to the aperture diaphragm S included in the first intermediate group GM1 decreases. Since it is desirable that the effect of correcting chromatic aberration of magnification by the second lens group G2 be large at the wide-angle end and small at the telephoto end, it is desirable that the second lens group G2 approaches the aperture diaphragm S at the telephoto end, and the height of the off-axis principal rays passing through the second lens group G2 decreases.

[0105] When the lower limit of condition (13) is exceeded, and the ratio of the distance from the top of the object's side of the lens closest to the object in the second lens group G2 to the aperture at the wide-angle and telephoto ends becomes small, the amount of change due to the scaling of the distance between the second lens group G2 and the aperture aperture S becomes small, and the change due to the scaling of the off-axis principal rays passing through the second lens group G2 becomes small. As a result, the change in the correction effect of chromatic aberration becomes small, making it difficult to effectively correct chromatic aberration throughout the entire zoom range, which is undesirable.

[0106] When the upper limit of condition (13) is exceeded, and the ratio of the distance from the top of the object's side surface to the aperture of the lens closest to the object in the second lens group G2 at the wide-angle and telephoto ends becomes large, the amount of change due to the scaling of the distance between the second lens group G2 and the aperture aperture S becomes large, requiring the off-axis light beam at the wide-angle end to pass through a higher point, which leads to an increase in the outer diameter of the second lens group G2, and is therefore undesirable.

[0107] Furthermore, regarding conditional equation (13), it is preferable to specify a lower limit of 1.4 and an upper limit of 3.5 to make the aforementioned effect more certain.

[0108] Furthermore, in the variable magnification imaging optical system of the present invention, the second intermediate group GM2 is the group that moves in the optical axis direction when focusing from an object at infinity to an object at a close distance, and it is desirable that it satisfies the following condition (14). (14) 0.05 < |fGM2 / fT| < 0.40 fGM2: Focal length of the second intermediate group GM2 in the front view fT: Total focal length of the system at the infinity telephoto end

[0109] Conditional equation (14) specifies the absolute value of the ratio between the focal length of the second intermediate group GM2 and the focal length of the entire system at the infinity telephoto end.

[0110] The second intermediate group GM2 is the group that moves in the optical axis direction when focusing from an object at infinity to an object at a close distance, and it is the group that moves the largest amount from infinity to the nearest end at the telephoto end. It is the group that plays a major role in the image plane correction effect, which corrects the shift in the image point that occurs when the object distance changes. Increasing the power of the second intermediate group GM2 can shorten the amount of movement during focusing, but this leads to a significant decrease in focusing performance, which is undesirable. By satisfying condition (14), it is possible to achieve both a faster focusing speed and suppression of the decrease in focusing performance.

[0111] When the lower limit of condition equation (14) is exceeded and the ratio of the focal length of the second intermediate group GM2 to the focal length of the entire system at the infinity telephoto end becomes small, the power of the second intermediate group GM2 becomes insufficient, the distance that the second intermediate group GM2 moves from infinity to the near end becomes longer, and a decrease in focusing speed occurs, which is undesirable.

[0112] When the upper limit of condition (14) is exceeded, and the ratio of the focal length of the second intermediate group GM2 to the focal length of the entire system at the infinity telephoto end becomes large, the power of the second intermediate group GM2 becomes too strong, which is undesirable because it leads to a large increase in performance fluctuations due to the deterioration of various aberrations during focusing.

[0113] Furthermore, regarding conditional equation (14), it is preferable to set the lower limit to 0.07 and the upper limit to 0.30 to make the aforementioned effect more certain.

[0114] Furthermore, in the variable-magnification imaging optical system of the present invention, it is desirable that the lens group closest to the image sensor among the lens groups constituting the subsequent group GR includes at least one concave lens that satisfies the following condition (15). Note that the concave lens referred to here may be a lens arranged individually or a concave lens arranged as part of a cemented lens. (15)ΔPgFnLr>0.009 ΔPgFnLr: The subsequent group GR Among the lens groups that make up the system, the lens group closest to the image sensor. Anomalous dispersion of concave lenses

[0115] Conditional equation (15) specifies the anomalous dispersion of concave lenses, which are desirable to include at least one in the image-side lens group among the lens groups constituting the subsequent group GR of the variable magnification imaging optical system of the present invention. In the variable magnification imaging optical system of the present invention, at the telephoto end, short wavelengths, especially light rays with wavelengths shorter than the g-line, are not adequately corrected, resulting in a decrease in imaging magnification and remaining chromatic aberration in the underexposure direction. To effectively correct this, it is desirable to use glass material with a large ΔPgF and strong positive anomalous dispersion for the concave lenses in the group behind the aperture diaphragm S.

[0116] When the lower limit of condition (15) is exceeded and the anomalous dispersion of the concave lens constituting the subsequent GR group decreases, the effect of overcorrecting the g line at the peripheral image height on the telephoto side decreases, making it difficult to correct chromatic aberration across the entire zoom range.

[0117] Furthermore, regarding the lower limit of conditional equation (15), it is possible to more reliably achieve the aforementioned effect by specifying the lower limit as 0.010, more preferably 0.011, and even more preferably 0.013.

[0118] Furthermore, in the variable magnification imaging optical system of the present invention, it is desirable that the lens group closest to the image sensor among the lens groups constituting the subsequent group GR includes at least one concave lens that satisfies the following condition (16). Note that the concave lens referred to here may be a lens arranged individually or a concave lens arranged as part of a cemented lens. (16) 0.80 < νd n Lr×ΔPgF n Lr νd n Lr: The aforementioned subsequent group The lens group closest to the image sensor among the lens groups that make up the GR. Abbe number of concave lens ΔPgF n Lr: The aforementioned subsequent group The lens group closest to the image sensor among the lens groups that make up the GR. Anomalous dispersion of concave lenses

[0119] Conditional equation (16) defines the relationship between the Abbe number and anomalous dispersion of concave lenses, which are desirable to include at least one in the image-side lens group among the lens groups constituting the subsequent group GR of the variable magnification imaging optical system of the present invention. In the variable magnification imaging optical system of the present invention, at the telephoto end, short wavelengths, especially light rays with wavelengths shorter than the g-line, are not adequately corrected, resulting in a decrease in imaging magnification and remaining chromatic aberration in the underexposure direction. To effectively correct this, it is desirable to use glass materials with a large ΔPgF and high positive anomalous dispersion for concave lenses in the group behind the aperture diaphragm S. Furthermore, glass materials that satisfy conditional equation (16) are generally glass materials with relatively low refractive indices of about 1.7 or less, which not only have anomalous dispersion desirable for correcting chromatic aberration but are also advantageous for correcting the Petzval sum due to their low refractive index.

[0120] When the lower limit of condition (16) is exceeded and the anomalous dispersion of the concave lens constituting the subsequent GR group decreases, the effect of overcorrecting the g line at the peripheral image height on the telephoto side decreases, making it difficult to correct chromatic aberration across the entire zoom range.

[0121] Furthermore, regarding the lower limit of conditional equation (16), it is preferable to set the lower limit to 0.85 to make the aforementioned effect more certain.

[0122] Furthermore, in the variable-magnification imaging optical system of the present invention, it is desirable that the lens group closest to the image sensor among the lens groups constituting the subsequent group GR includes at least one convex lens that satisfies the following condition (17). Note that the convex lens referred to here may be a lens arranged individually or a convex lens arranged as part of a cemented lens. (17)ΔPgFpLr<-0.0010 ΔPgFpLr: The aforementioned successor group GR Among the lens groups that make up the system, the lens group closest to the image sensor. Anomalous dispersion of convex lenses

[0123] Conditional equation (17) specifies the anomalous dispersion of at least one convex lens included in the image-side lens group among the lens groups constituting the subsequent group GR of the variable magnification imaging optical system of the present invention. In the variable magnification imaging optical system of the present invention, the imaging magnification decreases at the telephoto end for short wavelengths, especially for light rays from the g-line onwards, and chromatic aberration in the underexposure direction remains. To effectively correct this, it is desirable to use glass material with a small ΔPgF and strong negative anomalous dispersion for the convex lenses in the group behind the aperture diaphragm S.

[0124] The upper limit of condition (17) is exceeded, and the subsequent group GR Constitutes Of the lens groups, the lens group closest to the image is convex lens The difference When constant dispersion increases, the effect of overcorrecting the g-line at the telephoto end decreases, making it difficult to suppress chromatic aberration across the entire zoom range.

[0125] Furthermore, regarding conditional equation (17), the aforementioned effect can be made more certain by specifying the upper limit as -0.0020 if preferable, -0.0030 if more preferable, and -0.0040 if even more preferable.

[0126] Furthermore, in the variable-magnification imaging optical system of the present invention, it is desirable that the average value of the anomalous dispersion of the two convex lenses closest to the image side satisfies the range of condition equation (18). Note that the convex lenses referred to here may be lenses arranged individually or convex lenses arranged as part of a cemented lens. (18)ΔPgFprAVE<-0.0010 ΔPgFprAVE: Average value of the anomalous dispersion of the two convex lenses closest to the image.

[0127] Condition (18) is that in the variable magnification imaging optical system of the present invention, the two convex lenses counting from the image side Z This defines the average value of anomalous dispersion. In the variable magnification imaging optical system of the present invention, the imaging magnification decreases at the telephoto end for short wavelengths, especially for light rays from the g-line onwards, resulting in underexposure and residual chromatic aberration. To effectively correct this, it is desirable to use glass materials with small ΔPgF and strong negative anomalous dispersion for the convex lenses in the group behind the aperture diaphragm S.

[0128] The upper limit of condition (18) is exceeded, The two pieces closest to the statue Convex Len Z Anomalous dispersion average value As the value increases, the effect of overcorrecting the g-line at the telephoto end decreases, making it difficult to suppress chromatic aberration across the entire zoom range. When the upper limit of condition (18) is exceeded, and the anomalous dispersion of the two convex lenses closest to the image side that make up the subsequent GR group becomes large, the effect of overcorrecting the g line at the telephoto end decreases, making it difficult to suppress chromatic aberration across the entire zoom range.

[0129] Furthermore, regarding conditional equation (18), the aforementioned effect can be made more certain by specifying the upper limit as -0.0020 if preferable, -0.0030 if more preferable, and -0.0040 if even more preferable.

[0130] Furthermore, in the variable-magnification imaging optical system of the present invention, in order to prevent the mechanical mechanism from becoming more complex, it is desirable that the lens group closest to the image plane among the subsequent group GR be fixed to the image plane during zooming.

[0131] Next, the lens configuration of an embodiment relating to the imaging optical system of the present invention will be described. In the following explanation, the lens configuration will be described in order from the object side to the image side.

[0132] In the [Surface Data], the surface number is the number of the lens surface or aperture diaphragm S counted from the object side, r is the radius of curvature of each lens surface, d is the spacing between each lens surface, nd is the refractive index for the d line (wavelength 587.56 nm), vd is the Abbe number for the d line, and ΔPgF is a value calculated using the formula PgF - 0.64833 + 0.00180 × vd. Furthermore, the glass materials listed are examples of glass materials from HOYA, Ohara, Hikari Glass, and Schott, which correspond to the refractive index, Abbe number, and ΔPgF listed in the [Surface Data].

[0133] The asterisk (*) next to the lens surface number indicates that the lens surface is aspherical based on its shape. BF indicates the back focus, and the object surface distance indicates the distance from the subject to the first lens surface.

[0134] The (diaphragm) appended to the surface number indicates that an aperture diaphragm S is located at that position. The radius of curvature relative to the plane or aperture diaphragm S is indicated with ∞ (infinity).

[0135] The [Aspherical Data] section shows the values ​​of the coefficients that give the aspherical shape of the lens surface marked with an asterisk (*) in the [Surface Data] section. The shape of the aspherical surface is expressed by the following formula. In the following formula, y represents the displacement from the optical axis in the direction perpendicular to the optical axis, z represents the displacement (zack amount) in the direction of the optical axis from the intersection of the optical axis with the aspherical surface, r represents the radius of curvature of the reference sphere, and K represents the conic coefficient. The 4th, 6th, 8th, 10th, and 12th order aspherical coefficients are represented by A4, A6, A8, A10, and A12, respectively. TIFF0007878693000001.tif26123

[0136] The [Various Data] section shows values ​​such as focal length at each shooting distance and in-focus state.

[0137] The [Variable Interval Data] shows the BF value from the variable interval under various shooting distance focusing conditions.

[0138] The [Lens Group Data] shows the object-side face number for each lens group and the combined focal length of the entire group.

[0139] Furthermore, in the aberration diagrams corresponding to each embodiment, d, g, and C represent the d line, g line, and C line, respectively, and ΔS and ΔM represent the sagittal image plane and meridional image plane, respectively.

[0140] In addition, for all the specifications listed below, the units of focal length f, radius of curvature r, lens plane spacing d, and other lengths are millimeters (mm) unless otherwise specified. However, since similar optical performance can be obtained in proportional magnification and proportional reduction in optical systems, this is not the only unit used.

[0141] Furthermore, in the lens configuration diagrams of each embodiment, the arrows represent the trajectory of the lens group when changing magnification from the wide-angle end to the telephoto end, I is the image plane, F is the filter, and the dashed line passing through the center is the optical axis.

[0142] Next, the lens configuration of an embodiment relating to the imaging optical system of the present invention will be described. In the following explanation, the lens configuration will be described in order from the object side to the image side. [Examples]

[0143] Figure 1 is a diagram of the lens configuration of the variable magnification imaging optical system according to Example 1 when it is focused at the wide-angle end and infinity.

[0144] The variable magnification imaging optical system in Figure 1 consists of, in order from the object side, a first lens group G1 with positive refractive power, a second lens group G2 with positive refractive power, a third lens group G3 with negative refractive power, a first intermediate group GM1 consisting of a fourth lens group G4 and a fifth lens group G5, a second intermediate group GM2 consisting of a sixth lens group G6 that moves along the optical axis when focusing from an object at infinity to an object at close range, and a subsequent group GR consisting of a seventh lens group G7 and an eighth lens group G8.

[0145] Starting from the object side, the first lens group G1 consists of a concave meniscus lens with its convex surface facing the object, a biconvex lens, and a convex meniscus lens with its convex surface facing the object. The second lens group G2 consists of a cemented lens of a biconvex lens and a biconcave lens. The third lens group G3 consists of a cemented lens of a biconvex lens and a biconcave lens, a concave meniscus lens with its convex surface facing the object, a cemented lens of a biconcave lens and a biconvex lens, and a cemented lens of a biconcave lens and a convex meniscus lens with its convex surface facing the object. Furthermore, the third to fifth lenses from the object side of the third lens group G3 can be moved as a single unit in a direction approximately perpendicular to the optical axis to function as an image stabilization group. The fourth lens group G4 consists of a biconvex lens, a cemented lens of a biconvex lens and a concave meniscus lens with its convex surface facing the image side, and an aperture diaphragm S. The fifth lens group G5 consists of a cemented lens of a convex meniscus lens with its convex surface facing the object and a concave meniscus lens with its convex surface facing the object, and a cemented lens of a biconvex lens and a concave meniscus lens with its convex surface facing the image. The sixth lens group G6 consists of a cemented lens of a biconvex lens and a concave meniscus lens with its convex surface facing the image. The seventh lens group G7 consists of a cemented lens of a convex meniscus lens with its convex surface facing the image and a biconcave lens, and a cemented lens of a biconvex lens and a biconcave lens. The eighth lens group G8 consists of a cemented lens of a biconvex lens and a concave meniscus lens with its convex surface facing the image, and a biconcave lens.

[0146] When changing magnification from the wide-angle end to the telephoto end, the second lens group G2 and the eighth lens group G8 are fixed relative to the image plane, the first lens group G1 moves toward the object, the third lens group G3 to the seventh lens group each move toward the object, the distance between the first lens group G1 and the second lens group G2 increases, the distance between the second lens group G2 and the third lens group G3 decreases, the distance between the third lens group G3 and the fourth lens group G4 decreases, the distance between the fourth lens group G4 and the fifth lens group G5 decreases, the distance between the fifth lens group G5 and the sixth lens group G6 increases, the distance between the sixth lens group G6 and the seventh lens group G7 decreases, and the distance between the seventh lens group G7 and the eighth lens group G8 increases. When focusing from an object at infinity to an object at close range, the sixth lens group G6 moves toward the object along the optical axis.

[0147] The specifications of the variable magnification imaging optical system according to Example 1 are shown below. Numerical Example 1 Unit: mm [Surface data] Face number rd nd vd ΔPgF Applicable glass material 0 (d0) 1 219.7422 3.0000 1.55298 55.07 -0.0046 J-KZFH4 2 106.9237 0.1000 3 105.2496 12.8568 1.43875 94.66 0.0560 S-FPL55 4 -887.7919 0.3000 5 151.7135 7.3175 1.43875 94.66 0.0560 S-FPL55 6 689.3469 (d6) 7 87.1525 7.0725 1.77047 29.74 0.0002 NBFD29 8 -186.0599 1.7999 1.92286 20.88 0.0281 E-FDS1-W 9 1547.9303 (d9) 10 174.7842 4.0192 1.67270 32.17 0.0058 E-FD5 11 -98.3967 1.0000 1.91082 35.25 -0.0028 TAFD35 12 60.6855 5.8318 13 693.6052 1.0000 1.90525 35.04 -0.0005 S-LAH93 14 78.2972 3.6005 15 -52.4329 1.0000 1.80420 46.50 -0.0075 TAF3D 16 76.3499 3.8350 1.85451 25.15 0.0071 NBFD25 17 -241.0723 4.0000 18 -253.0121 1.0000 1.73037 32.23 -0.0005 NBFD32 19 46.8796 4.4089 1.85451 25.15 0.0071 NBFD25 20 334.9554 (d20) 21 177.7534 5.0873 1.59410 60.47 0.0156 FCD600 22 -62.7130 0.3000 23 73.0028 6.4463 1.43700 95.10 0.0564 FCD100 24 -56.9799 1.0000 1.91082 35.25 -0.0028 TAFD35 25 -296.3370 3.0000 26 (aperture) ∞ (d26) 27 44.0513 4.4496 1.49700 81.61 0.0373 FCD1 28 225.0247 0.9002 1.91082 35.25 -0.0028 TAFD35 29 51.1236 4.1248 30 291.1313 5.4778 1.51742 52.15 0.0044 E-CF6 31 -45.1872 0.9500 1.90043 37.37 -0.0045 TAFD37A 32 -61.1543 (d32) 33 62.9961 6.4690 1.59551 39.24 0.0026 S-TIM8 34 -78.7521 0.9000 1.90525 35.04 -0.0005 S-LAH93 35 -267.8528 (d35) 36 -170.7690 6.7388 1.82166 24.04 0.0186 MC-FDS910-50 37 -67.8981 1.0000 1.76385 48.49 -0.0022 S-LAH96 38 50.4060 2.3336 39 62.6479 6.5417 1.61340 44.27 -0.0054 S-NBM51 40 -45.1541 1.0000 1.43700 95.10 0.0564 FCD100 41 75.6923 (d41) 42 105.0556 6.8481 1.61340 44.27 -0.0054 S-NBM51 43 -40.3980 1.0000 1.59282 68.62 0.0192 FCD515 44 -69.8535 8.1268 45 -58.2019 1.0001 1.95375 32.32 -0.0002 TAFD45 46 196.8911 37.9233 47 ∞ 2.5000 1.51680 64.20 0.0014 BSC7 48 ∞ (BF) [Various Data] Zoom ratio 3.74 Wide-angle (INF) Intermediate (INF) Telephoto (INF) Focal length 154.50 300.00 577.80 F-number 4.70 5.21 6.46 Full angle of view 2ω 15.56 8.04 4.18 Image height Y 21.63 21.63 21.63 Overall lens length 300.00 350.00 420.00 [Variable interval data] Wide angle (INF) Wide angle (close distance) Medium (INF) (d0) ∞ 2500.8704 ∞ (d6) 14.5648 14.5648 64.5649 (d9) 19.2200 19.2200 16.2362 (d20) 21.9127 21.9127 2.0000 (d26) 42.2772 42.2772 35.4570 (d32) 5.2027 2.0000 24.6206 (d35) 17.1492 20.3519 27.4616 (d41) 2.4139 2.4139 2.4002 (BF) 1.0000 1.0000 1.0000 Medium (close distance) Telephoto (INF) Telephoto (close distance) (d0) 2456.2252 ∞ 2420.8805 (d6) 64.5649 134.5649 134.5649 (d9) 16.2362 2.0814 2.0814 (d20) 2.0000 2.0000 2.0000 (d26) 35.4570 20.8842 20.8842 (d32) 14.0812 22.8519 2.0000 (d35) 38.0010 3.5000 24.3519 (d41) 2.4002 56.8581 56.8581 (BF) 1.0000 1.0000 1.0000 [Lens group data] Group Starting surface Focal length G1 1 236.2152 G2 7 133.6947 G3 10 -24.2947 G4 21 72.1099 G5 27 254.9799 G6 33 112.2107 G7 36 -90.5197 G8 42 -283.6465 [Examples]

[0148] Figure 11 is a diagram of the lens configuration of the variable magnification imaging optical system according to Example 2 when it is focused at the wide-angle end and infinity.

[0149] The variable magnification imaging optical system in Figure 11 consists of, in order from the object side, a first lens group G1 with positive refractive power, a second lens group G2 with positive refractive power, a third lens group G3 with negative refractive power, a first intermediate group GM1 consisting of a fourth lens group G4 and a fifth lens group G5, a second intermediate group GM2 consisting of a sixth lens group G6 that moves along the optical axis when focusing from an object at infinity to an object at close range, and a subsequent group GR consisting of a seventh lens group G7 and an eighth lens group G8.

[0150] Starting from the object side, the first lens group G1 consists of a concave meniscus lens with its convex surface facing the object, a biconvex lens, and a convex meniscus lens with its convex surface facing the object. The second lens group G2 consists of a biconvex lens and a biconcave lens. The third lens group G3 consists of a cemented lens of a biconvex lens and a biconcave lens, a convex meniscus lens with its convex surface facing the object, a biconcave lens, and a cemented lens of a biconcave lens and a biconvex lens. Furthermore, the fourth lens from the object side of the third lens group G3 can be moved as a single unit in a direction approximately perpendicular to the optical axis to function as an image stabilization group. The fourth lens group G4 consists of a biconvex lens, a cemented lens of a biconvex lens and a concave meniscus lens with its convex surface facing the image side, and an aperture diaphragm S. The fifth lens group G5 consists of a cemented lens of a biconvex lens and a biconcave lens, and a cemented lens of a biconvex lens and a concave meniscus lens with its convex surface facing the image side. The sixth lens group G6 consists of a cemented lens made of a biconvex lens and a concave meniscus lens with its convex surface facing the image side. The seventh lens group G7 consists of a cemented lens made of a convex meniscus lens with its convex surface facing the image side and a biconcave lens, and a cemented lens made of a biconvex lens and a biconcave lens. The eighth lens group G8 consists of a cemented lens made of a biconvex lens and a concave meniscus lens with its convex surface facing the image side, and a biconcave lens.

[0151] When changing magnification from the wide-angle end to the telephoto end, the second lens group G2 and the eighth lens group G8 are fixed relative to the image plane, the first lens group G1 moves toward the object, the third lens group G3 to the fifth lens group G5 each move toward the object, the sixth lens group G6 moves toward the image, the seventh lens group G7 moves toward the object, the distance between the first lens group G1 and the second lens group G2 increases, and the distance between the second lens group G2 and the third lens group G3 decreases. As the distance between the third lens group G3 and the fourth lens group G4 decreases, the distance between the fourth lens group G4 and the fifth lens group G5 decreases, the distance between the fifth lens group G5 and the sixth lens group G6 increases, the distance between the sixth lens group G6 and the seventh lens group G7 decreases, and the distance between the seventh lens group G7 and the eighth lens group G8 increases, when focusing from an object at infinity to an object at close range, the sixth lens group G6 moves towards the object along the optical axis.

[0152] The specifications of the variable magnification imaging optical system according to Example 2 are shown below. Numerical Example 2 Unit: mm [Surface data] Face number rd nd vd ΔPgF Applicable glass material 0 (d0) 1 313.9338 3.0000 1.61310 44.36 -0.0081 E-ADF10 2 127.3297 0.1000 3 125.9137 11.6998 1.43875 94.66 0.0560 S-FPL55 4 -833.5680 0.3000 5 138.0867 9.0391 1.43875 94.66 0.0560 S-FPL55 6 1594.3893 (d6) 7 107.9327 7.0586 1.65100 56.24 -0.0051 S-LAL54Q 8 -231.9455 1.0000 9 -213.8532 1.8000 1.66382 27.35 0.0327 J-SFH4 10 1071.3941 (d10) 11 574.4265 4.4878 1.80518 25.46 0.0131 FD60-W 12 -52.6286 1.0000 1.90525 35.04 -0.0005 S-LAH93 13 37.9856 2.4328 14 44.7912 3.2062 1.76182 26.61 0.0117 FD140 15 87.7005 9.2366 16 -100.1820 0.9000 1.72000 50.23 -0.0059 S-LAL10 17 78.6274 3.7951 18 -42.8383 1.0000 1.77250 49.62 -0.0088 TAF1 19 163.9164 4.2467 1.85451 25.15 0.0071 NBFD25 20 -70.2739 (d20) 21 2035.1510 3.4815 1.59410 60.47 0.0156 FCD600 22 -92.8817 0.3000 23 58.8047 6.7735 1.49700 81.61 0.0373 FCD1 24 -58.6839 1.0000 1.65100 56.24 -0.0051 S-LAL54Q 25 -301.5263 3.0000 26 (Aperture) ∞ (d26) 27 37.9545 6.6018 1.43700 95.10 0.0564 FCD100 28 -163.8613 0.8999 1.85883 30.00 0.0035 NBFD30 29 47.4767 3.7133 30 128.5643 9.6559 1.65412 39.68 -0.0033 S-NBH5 31 -23.2865 1.0000 1.63854 55.38 -0.0002 S-BSM18 32 -73.5050 (d32) 33 51.4169 5.6996 1.48749 70.44 0.0090 FC5 34 -65.9030 0.9000 1.91082 35.25 -0.0028 TAFD35 35 -191.4230 (d35) 36 -65.2151 6.3532 1.84666 23.78 0.0136 FDS90-SG 37 -24.7782 0.8999 1.90525 35.04 -0.0005 S-LAH93 38 43.6797 2.0172 39 50.8986 8.8198 1.58144 40.89 0.0019 E-FL5 40 -22.6122 1.0499 1.43700 95.10 0.0564 FCD100 41 288.4604 (d41) 42 69.8285 12.0000 1.61340 44.27 -0.0054 S-NBM51 43 -29.9473 1.0001 1.66382 27.35 0.0327 J-SFH4 44 -50.2469 7.6319 45 -46.6736 1.0003 2.00100 29.13 0.0035 TAFD55-W 46 1278.0408 38.0000 47 ∞ 2.5000 1.51680 64.20 0.0014 BSC7 48 ∞ (BF) [Various Data] Zoom ratio 3.74 Wide-angle (INF) Intermediate (INF) Telephoto (INF) Focal length 154.50 300.00 577.80 F-number 4.70 5.21 6.46 Full angle of view 2ω 15.58 8.02 4.18 Image height Y 21.63 21.63 21.63 Lens length: 291.24 x 350.00 x 416.24 [Variable interval data] Wide-angle (INF) Wide-angle (close-up) Intermediate (INF) (d0) ∞ 2500.0000 ∞ (d6) 5.3029 5.3029 64.0600 (d10) 29.4531 29.4531 26.5873 (d20) 18.2967 1 8.2967 7.6367 (d26) 18.9828 18.9828 13.1925 (d32) 4.6509 2.0000 27.7941 (d35) 22.9563 25.6072 19.1294 (d41) 2.0000 2.0000 2.0000 (BF) 1.0000 1.0000 1.0000 Intermediate (close range) Telephoto (INF) Telephoto (close range) (d0) 2500.0000 ∞ 2500.0000 (d6) 64.0600 130.3029 130.3029 (d10) 26.5873 9.9805 9.9805 (d20) 7.6367 2.0000 2.0000 (d26) 13.1925 2.0000 2.0000 (d32) 18.5365 61.3459 35.2387 (d35) 28.3870 3.5000 29.6072 (d41) 2.0000 17.5135 17.5135 (BF) 1.0000 1.0000 1.0000 [Lens group data] Group starting plane focal length G1 1 247.8803 G2 7 193.2477 G3 11 -24.5769 G4 21 68.1910 G5 27 160.1374 G6 33 127.0838 G7 36 -54.8179 G8 42 469.5596 [Examples]

[0153] Figure 21 is a diagram of the lens configuration of the variable magnification imaging optical system according to Example 3 when it is focused at the wide-angle end and infinity.

[0154] The variable magnification imaging optical system in Figure 21 consists, in order from the object side, of a first lens group G1 with positive refractive power, a second lens group G2 with positive refractive power, a third lens group G3 with negative refractive power, a first intermediate group GM1 consisting of a fourth lens group G4 and a fifth lens group G5, a second intermediate group GM2 consisting of a sixth lens group G6 that moves along the optical axis when focusing from an object at infinity to an object at close range, and a subsequent group GR consisting of a seventh lens group G7 and an eighth lens group G8.

[0155] Starting from the object side, the first lens group G1 consists of a concave meniscus lens with its convex surface facing the object, a biconvex lens, and a convex meniscus lens with its convex surface facing the object. The second lens group G2 consists of a cemented lens of a biconvex lens and a concave meniscus lens with its convex surface facing the image side. The third lens group G3 consists of a convex meniscus lens with its convex surface facing the image side, a biconcave lens, a cemented lens of a biconcave lens and a biconvex lens, and a cemented lens of a biconcave lens and a convex meniscus lens with its convex surface facing the object side. Furthermore, the second to fourth lenses from the object side of the third lens group G3 can be moved as a single unit in a direction approximately perpendicular to the optical axis to function as an image stabilization group. The fourth lens group G4 consists of a biconvex lens, a cemented lens of a biconvex lens and a concave meniscus lens with its convex surface facing the image side, and an aperture diaphragm S. The fifth lens group G5 consists of a biconvex lens and a cemented lens of a convex meniscus lens with its convex surface facing the object and a concave meniscus lens with its convex surface facing the object. The sixth lens group G6 consists of a biconvex lens and a cemented lens of a concave meniscus lens with its convex surface facing the image. The seventh lens group G7 consists of a cemented lens of a convex meniscus lens with its convex surface facing the image and a biconcave lens, a concave meniscus lens with its convex surface facing the object, and a cemented lens of a biconvex lens and a biconcave lens. The eighth lens group G8 consists of a cemented lens of a biconvex lens and a concave meniscus lens with its convex surface facing the image and a concave meniscus aspherical lens with its convex surface facing the image and the image-side surface having a predetermined aspherical shape.

[0156] When changing magnification from the wide-angle end to the telephoto end, the second lens group G2 and the eighth lens group G8 are fixed relative to the image plane, the first lens group G1 moves toward the object, the third lens group G3 to the seventh lens group G7 each move toward the object, the distance between the first lens group G1 and the second lens group G2 increases, the distance between the second lens group G2 and the third lens group G3 decreases, the distance between the third lens group G3 and the fourth lens group G4 decreases, the distance between the fourth lens group G4 and the fifth lens group G5 increases, the distance between the fifth lens group G5 and the sixth lens group G6 increases, the distance between the sixth lens group G6 and the seventh lens group G7 decreases, and the distance between the seventh lens group G7 and the eighth lens group G8 increases. When focusing from an object at infinity to an object at close range, the sixth lens group G6 moves toward the object along the optical axis.

[0157] The specifications of the variable magnification imaging optical system according to Example 3 are shown below. Numerical Example 3 Unit: mm [Surface data] Face number rd nd vd ΔPgF Applicable glass material 0 (d0) 1 460.1969 2.9999 1.61310 44.36 -0.0081 E-ADF10 2 144.3557 0.1001 3 146.1176 11.4069 1.49700 81.54 0.0358 S-FPL51 4 -383.1217 0.2999 5 129.8536 6.6197 1.43875 94.66 0.0560 S-FPL55 6 293.7912 (d6) 7 372.9594 6.6746 1.64769 33.84 0.0049 E-FD2 8 -108.0460 1.5999 2.00069 25.46 0.0110 TAFD40-W 9 -261.4735 (d9) 10 -166.7703 2.9439 1.84666 23.78 0.0136 FDS90-SG 11 -83.2672 3.0504 12 -12057.0943 1.0000 1.90366 31.31 0.0027 TAFD25 13 95.9526 3.5302 14 -65.3746 1.0000 1.76385 48.49 -0.0022 S-LAH96 15 74.5154 4.4834 1.85451 25.15 0.0071 NBFD25 16 -150.8650 4.4158 17 -42.6539 1.0000 1.76385 48.49 -0.0022 S-LAH96 18 132.3897 2.9598 1.78880 28.43 0.0036 S-NBH58 19 6684.9210 (d19) 20 183.5007 4.1010 1.76385 48.49 -0.0022 S-LAH96 21 -110.8685 0.3000 22 55.3723 7.1568 1.43700 95.10 0.0564 FCD100 23 -60.4223 1.0000 1.77250 49.62 -0.0088 TAF1 24 -2514.0968 9.1908 25 (aperture) ∞ (d25) 26 87.2101 5.0861 1.49700 81.61 0.0373 FCD1 27 -91.0250 0.3000 28 28.7399 5.8998 1.49700 81.61 0.0373 FCD1 29 277.0772 1.0000 1.90043 37.37 -0.0045 TAFD37A 30 27.8069 (d30) 31 46.1337 5.0740 1.66672 48.32 -0.0005 S-BAH11 32 -33.6662 0.8999 1.76385 48.49 -0.0022 S-LAH96 33 -230.9634 (d33) 34 -99.1145 3.2044 1.67270 32.17 0.0058 E-FD5 35 -38.2447 5.4822 1.90525 35.04 -0.0005 S-LAH93 36 60.8790 2.2476 37 84.7442 0.9000 1.92286 20.88 0.0281 E-FDS1-W 38 32.6857 8.7431 1.73037 32.23 -0.0005 NBFD32 39 -22.7609 0.9999 1.49700 81.61 0.0373 FCD1 40 210.7969 (d40) 41 420.1833 7.8310 1.61310 44.36 -0.0081 E-ADF10 42 -22.7815 1.0000 1.53775 74.70 0.0254 S-FPM3 43 -287.9967 11.3260 44 -28.0781 1.1999 1.88202 37.22 -0.0045 MC-TAFD307 *45 -44.9175 34.4699 46 ∞ 2.5000 1.51680 64.20 0.0014 BSC7 47 ∞ (BF) [Aspherical data] 45 sides K 0.00000 A4 -1.55718E-06 A6 -3.01153E-09 A8 2.01865E-11 A10 -9.56512E-14 A12 1.65968E-16 [Various Data] Zoom ratio 4.05 Wide-angle (INF) Intermediate (INF) Telephoto (INF) Focal length 142.50 285.00 577.80 F-number 4.70 5.21 6.46 Full angle of view 2ω 16.98 8.51 4.18 Image height Y 21.63 21.63 21.63 Lens length: 280.00 342.20 410.00 [Variable interval data] Wide-angle (INF) Wide-angle (close-up) Intermediate (INF) (d0) ∞ 2500.8704 ∞ (d6) 10.4783 10.4783 72.6827 (d9) 38.9360 38.9360 35.5312 (d19) 29.0250 29.0250 11.8823 (d25) 2.0000 2.0000 4.5485 (d30) 9.1174 7.4493 27.1241 (d33) 8.7738 10.4419 13.2388 (d40) 6.6722 6.6722 2.1995 (BF) 1.0000 1.0000 1.0000 Intermediate (close range) Telephoto (INF) Telephoto (close range) (d0) 2456.2252 ∞ 2420.8805 (d6) 72.6827 140.4784 140.4784 (d9) 35.5312 13.8280 13.8280 (d19) 11.8823 2.0000 2.0000 (d25) 4.5485 2.4555 2.4555 (d30) 20.7123 40.2991 23.9079 (d33) 19.6507 2.3978 18.7889 (d40) 2.1995 33.5441 33.5441 (BF) 1.0000 1.0000 1.0000 [Lens group data] Group starting plane focal length G1 1 271.1762 G2 7 435.3000 G3 10 -35.4692 G4 20 70.9917 G5 26 611.7602 G6 31 67.4052 G7 34 -75.3409 G8 41 -255.8215 [Examples]

[0158] Figure 31 is a diagram of the lens configuration of the variable magnification imaging optical system according to Example 4 when it is focused at the wide-angle end and infinity.

[0159] The variable magnification imaging optical system in Figure 31 consists of, in order from the object side, a first lens group G1 with positive refractive power, a second lens group G2 with positive refractive power, a third lens group G3 with negative refractive power, a first intermediate group GM1 consisting of a fourth lens group G4 and a fifth lens group G5, a second intermediate group GM2 consisting of a sixth lens group G6 that moves along the optical axis when focusing from an object at infinity to an object at close range, and a subsequent group GR consisting of a seventh lens group G7 and an eighth lens group G8.

[0160] Starting from the object side, the first lens group G1 consists of a concave meniscus lens with its convex surface facing the object, a biconvex lens, and a convex meniscus lens with its convex surface facing the object. The second lens group G2 consists of a cemented lens of a biconvex lens and a concave meniscus lens with its convex surface facing the image side. The third lens group G3 consists of a convex meniscus lens with its convex surface facing the image side, a concave meniscus lens with its convex surface facing the object side, a cemented lens of a biconcave lens and a biconvex lens, and a cemented lens of a biconcave lens and a convex meniscus lens with its convex surface facing the object side. Furthermore, the second to fourth lenses from the object side of the third lens group G3 can be moved as a single unit in a direction approximately perpendicular to the optical axis to function as an image stabilization group. The fourth lens group G4 consists of a biconvex lens, a cemented lens of a biconvex lens and a biconcave lens, and an aperture diaphragm S. The fifth lens group G5 consists of a biconvex lens and a cemented lens of a biconvex lens and a biconcave lens. The sixth lens group G6 consists of a cemented lens of a biconvex lens and a concave meniscus lens with its convex surface facing the image side. The seventh lens group G7 consists of a cemented lens of a convex meniscus lens with its convex surface facing the image side and a biconcave lens, and a cemented lens of a concave meniscus lens with its convex surface facing the object side and a biconvex lens and a biconcave lens. The eighth lens group G8 consists of a cemented lens of a biconvex lens and a biconcave lens, and a concave meniscus aspherical lens with its convex surface facing the image side and the image-side surface having a predetermined aspherical shape.

[0161] When changing magnification from the wide-angle end to the telephoto end, the second lens group G2 and the eighth lens group G8 are fixed relative to the image plane, the first lens group G1 moves toward the object, the third lens group G3 to the seventh lens group G7 each move toward the object, the distance between the first lens group G1 and the second lens group G2 increases, the distance between the second lens group G2 and the third lens group G3 decreases, the distance between the third lens group G3 and the fourth lens group G4 decreases, the distance between the fourth lens group G4 and the fifth lens group G5 decreases, the distance between the fifth lens group G5 and the sixth lens group G6 increases, the distance between the sixth lens group G6 and the seventh lens group G7 decreases, and the distance between the seventh lens group G7 and the eighth lens group G8 increases. When focusing from an object at infinity to an object at close range, the sixth lens group G6 moves toward the object along the optical axis.

[0162] The specifications of the variable magnification imaging optical system according to Example 4 are shown below. Numerical Example 4 Unit: mm [Surface data] Face number rd nd vd ΔPgF Applicable glass material 0 (d0) 1 564.7048 3.0000 1.61336 44.49 -0.0094 N-KZFS4HT 2 168.6119 0.1000 3 169.5152 9.5011 1.49700 81.54 0.0358 S-FPL51 4 -593.6297 0.3000 5 142.5243 7.7748 1.43875 94.66 0.0560 S-FPL55 6 540.7236 (d6) 7 179.5996 6.1309 1.67270 32.17 0.0058 E-FD5 8 -177.9787 1.6000 1.92286 20.88 0.0281 E-FDS1-W 9 -572.0899 (d9) 10 -394.5217 2.4345 1.84666 23.78 0.0136 FDS90-SG 11 -188.5246 4.2219 12 2857.7287 1.0307 1.90525 35.04 -0.0005 S-LAH93 13 86.5725 3.5770 14 -69.2223 1.0000 1.76385 48.49 -0.0022 S-LAH96 15 69.2201 4.3621 1.85451 25.15 0.0071 NBFD25 16 -268.9390 4.3334 17 -59.0003 2.8124 1.77250 49.62 -0.0088 TAF1 18 172.5992 3.5327 1.90525 35.04 -0.0005 S-LAH93 19 2929.2995 (d19) 20 148.5159 5.7273 1.59282 68.62 0.0192 FCD515 21 -70.1853 0.3000 22 47.6224 9.1480 1.43700 95.10 0.0564 FCD100 23 -42.4210 1.0000 1.85135 40.10 -0.0067 MC-TAFD305 24 463.8381 3.2424 25 (aperture) ∞ (d25) 26 416.8343 5.3513 1.64769 33.84 0.0049 E-FD2 27 -52.1138 0.3000 28 39.4632 8.7845 1.43700 95.10 0.0564 FCD100 29 -86.4104 1.2700 1.87071 40.73 -0.0069 TAFD32 30 39.4015 (d30) 31 51.4786 4.6293 1.65412 39.68 -0.0033 S-NBH5 32 -40.5971 0.8999 1.90525 35.04 -0.0005 S-LAH93 33 -110.4973 (d33) 34 -94.0501 2.4659 1.85451 25.15 0.0071 NBFD25 35 -58.8174 1.0000 1.90525 35.04 -0.0005 S-LAH93 36 54.9816 3.6316 37 67.8676 0.9000 1.92286 20.88 0.0281 E-FDS1-W 38 34.5405 7.9312 1.73037 32.23 -0.0005 NBFD32 39 -27.2772 0.9999 1.49700 81.61 0.0373 FCD1 40 132.5925 (d40) 41 210.0613 7.8013 1.55836 54.01 -0.0094 N-KZFS2 42 -23.0240 0.9999 1.49700 81.61 0.0373 FCD1 43 1285.7572 12.8578 44 -27.5271 1.1999 1.88202 37.22 -0.0045 MC-TAFD307 *45 -42.7168 30.5000 46 ∞ 2.5000 1.51680 64.20 0.0014 BSC7 47 ∞ (BF) [Aspherical data] 45 sides K 0.00000 A4 -1.58639E-06 A6 -3.76873E-09 A8 1.65667E-11 A10 -4.44955E-14 A12 4.39343E-17 [Various Data] Zoom ratio 4.05 Wide-angle (INF) Intermediate (INF) Telephoto (INF) Focal length 142.50 285.00 577.80 F-number 4.70 5.21 6.46 Full angle of view 2ω 16.96 8.50 4.18 Image height Y 21.63 21.63 21.63 Lens length: 280.00 341.50 410.00 [Variable interval data] Wide-angle (INF) Wide-angle (close-up) Intermediate (INF) (d0) ∞ 2500.8704 ∞ (d6) 13.8517 13.8517 75.3488 (d9) 30.3567 30.3567 30.2087 (d19) 34.1319 34.1319 15.5301 (d25) 10.5193 10.5193 7.5385 (d30) 4.8460 2.9468 24.8768 (d33) 13.9437 15.8429 15.1764 (d40) 2.1989 2.1989 2.6659 (BF) 1.0000 1.0000 1.0000 Intermediate (close range) Telephoto (INF) Telephoto (close range) (d0) 2456.2252 ∞ 2420.8805 (d6) 75.3488 143.8517 143.8517 (d9) 30.2087 15.4140 15.4140 (d19) 15.5301 3.8418 3.8418 (d25) 7.5385 2.2029 2.2029 (d30) 17.9019 31.7645 14.4748 (d33) 22.1513 2.1872 19.4768 (d40) 2.6659 40.5862 40.5862 (BF) 1.0000 1.0000 1.0000 [Lens group data] Group starting plane focal length G1 1 286.3959 G2 7 253.3497 G3 10 -35.1007 G4 20 86.7866 G5 26 406.4777 G6 31 68.4201 G7 34 -83.0562 G8 41 -190.4140 [Examples]

[0163] Figure 41 is a diagram of the lens configuration of the variable magnification imaging optical system according to Example 5 when it is focused at the wide-angle end and infinity.

[0164] The variable magnification imaging optical system in Figure 41 consists of, in order from the object side, a first lens group G1 with positive refractive power, a second lens group G2 with positive refractive power, a third lens group G3 with negative refractive power, a first intermediate group GM1 consisting of a fourth lens group G4, a fifth lens group G5, and a sixth lens group G6 that moves along the optical axis when focusing from an object at infinity to an object at close range, a second intermediate group GM2 consisting of a seventh lens group G7 that moves along the optical axis when focusing from an object at infinity to an object at close range, and a subsequent group GR consisting of an eighth lens group G8 and a ninth lens group G9.

[0165] Starting from the object side, the first lens group G1 consists of a concave meniscus lens with its convex surface facing the object, a convex meniscus lens with its convex surface facing the object, and another convex meniscus lens with its convex surface facing the object. The second lens group G2 consists of a cemented lens of a biconvex lens and a concave meniscus lens with its convex surface facing the image side. The third lens group G3 consists of a cemented lens of a biconvex lens and a biconcave lens, a concave meniscus lens with its convex surface facing the object, a cemented lens of a biconcave lens and a convex meniscus lens with its convex surface facing the object, and a cemented lens of a biconcave lens and a convex meniscus lens with its convex surface facing the object. Furthermore, the third to fifth lenses from the object side of the third lens group G3 can be moved as a single unit in a direction approximately perpendicular to the optical axis to function as an image stabilization group. The fourth lens group G4 consists of a biconvex lens, a cemented lens of a biconvex lens and a concave meniscus lens with its convex surface facing the image side, and an aperture diaphragm S. The fifth lens group G5 consists of a cemented lens made of a biconcave lens and a biconvex lens. The sixth lens group G6 consists of a cemented lens made of a convex meniscus lens with its convex surface facing the image side and a concave meniscus lens with its convex surface facing the image side. The seventh lens group G7 consists of a cemented lens made of a biconvex lens and a concave meniscus lens with its convex surface facing the image side. The eighth lens group G8 consists of a cemented lens made of a convex meniscus lens with its convex surface facing the image side and a biconcave lens, and a cemented lens made of a biconvex lens and a biconcave lens. The ninth lens group G9 consists of a cemented lens made of a biconvex lens and a concave meniscus lens with its convex surface facing the image side and a concave meniscus lens with its convex surface facing the image side.

[0166] When changing magnification from the wide-angle end to the telephoto end, the second lens group G2 and the ninth lens group G9 are fixed relative to the image plane, the first lens group G1 moves toward the object, the third lens group G3 to the eighth lens group G8 each move toward the object, the distance between the first lens group G1 and the second lens group G2 increases, the distance between the second lens group G2 and the third lens group G3 decreases, the distance between the third lens group G3 and the fourth lens group G4 decreases, and the fourth lens group G4 and The spacing of the fifth lens group G5 decreases, the spacing between the fifth lens group G5 and the sixth lens group G6 decreases, the spacing between the sixth lens group G6 and the seventh lens group G7 increases, the spacing between the seventh lens group G7 and the eighth lens group G8 decreases, and the spacing between the eighth lens group G8 and the ninth lens group G9 increases. When focusing from an object at infinity to a near-field object, the sixth lens group G6 moves along the optical axis toward the image, and the seventh lens group G7 moves toward the object. Also, the amount of movement due to focusing from an object at infinity to the near-field at the telephoto end is greater for the seventh lens group G7 than for the sixth lens group G6 (however, the positive or negative direction of movement is not considered, and the comparison is made as a simple amount of movement).

[0167] The specifications of the variable magnification imaging optical system according to Example 5 are shown below. Numerical Example 5 Unit: mm [Surface data] Face number rd nd vd ΔPgF Applicable glass material 0 (d0) 1 269.9273 3.0000 1.61340 44.27 -0.0054 S-NBM51 2 112.6692 0.0999 3 111.5395 10.8116 1.49700 81.54 0.0358 S-FPL51 4 4431.7465 0.3000 5 147.0967 8.6478 1.43875 94.66 0.0560 S-FPL55 6 1789.1499 (d6) 7 93.0903 8.9999 1.72047 34.71 -0.0025 S-NBH8 8 -192.1464 1.7999 1.92286 18.90 0.0351 S-NPH2 9 -2966.3666 (d9) 10 124.9236 5.9007 1.84666 23.78 0.0136 FDS90-SG 11 -63.2375 1.0000 1.90043 37.37 -0.0045 TAFD37A 12 80.8045 5.4503 13 1061.7755 1.0000 1.90525 35.04 -0.0005 S-LAH93 14 77.6033 3.5062 15 -88.9429 1.0000 1.83481 42.74 -0.0066 S-LAH55VS 16 35.8630 5.1380 1.85451 25.15 0.0071 NBFD25 17 1633.7080 4.4725 18 -220.9096 1.0000 1.76182 26.61 0.0117 FD140 19 27.8597 6.1137 1.80610 33.27 -0.0001 NBFD15-W 20 215.5665 (d20) 21 102.4311 5.2026 1.49700 81.54 0.0358 S-FPL51 22 -65.8729 0.3000 23 63.4528 6.1678 1.43875 94.66 0.0560 S-FPL55 24 -54.9579 1.0000 1.88300 40.80 -0.0094 TAFD30 25 -292.0657 3.0000 26 (aperture) ∞ (d26) 27 -78.3364 1.0000 1.91082 35.25 -0.0028 TAFD35 28 90.9975 4.7536 1.43875 94.66 0.0560 S-FPL55 29 -77.8299 (d29) 30 -124.4927 5.3385 1.67270 32.10 0.0082 S-TIM25 31 -31.4622 0.9499 1.76385 48.49 -0.0022 S-LAH96 32 -47.3462 (d32) 33 72.9305 5.7314 1.66672 48.32 -0.0005 S-BAH11 34 -64.2889 0.8999 1.95375 32.32 0.0003 S-LAH98 35 -184.7573 (d35) 36 -163.6179 3.8259 1.77047 29.74 0.0002 NBFD29 37 -43.4046 1.0000 1.74400 44.79 -0.0023 S-LAM2 38 46.5819 2.1548 39 52.6726 6.5589 1.61310 44.36 -0.0081 E-ADF10 40 -46.9173 1.0000 1.43875 94.66 0.0560 S-FPL55 41 80.5430 (d41) 42 2222.8876 5.6807 1.74951 35.33 -0.0030 S-NBH51 43 -39.1070 1.0000 1.66382 27.35 0.0327 J-SFH4 44 -62.6396 11.5075 45 -45.4337 1.0000 1.95375 32.32 0.0003 S-LAH98 46 -635.9184 36.3700 47 ∞ 2.5000 1.51680 64.20 0.0014 BSC7 48 ∞ (BF) [Various Data] Zoom ratio 3.74 Wide-angle (INF) Intermediate (INF) Telephoto (INF) Focal length 154.50 300.00 577.80 F-number 4.70 5.21 6.46 Full angle of view 2ω 15.56 8.03 4.18 Image height Y 21.63 21.63 21.63 Lens length: 300.00, 350.00, 420.00 [Variable interval data] Wide-angle (INF) Wide-angle (close-up) Intermediate (INF) (d0) ∞ 2500.8704 ∞ (d6) 16.6869 16.6869 66.6870 (d9) 18.0478 18.0478 15.9695 (d20) 38.5525 38.5525 12.0672 (d26) 16.5842 16.5842 3.1178 (d29) 6.4338 7.3076 5.1656 (d32) 6.2156 2.0000 46.1654 (d35) 18.0591 21.4009 17.9697 (d41) 3.2384 3.2384 6.6762 (BF) 1.0000 1.0000 1.0000 Intermediate (close range) Telephoto (INF) Telephoto (close range) (d0) 2456.2252 ∞ 2420.8805 (d6) 66.6870 136.6870 136.6870 (d9) 15.9695 2.0000 2.0000 (d20) 12.0672 2.0000 2.0000 (d26) 3.1178 3.1718 3.1718 (d29) 5.7549 2.0000 5.6112 (d32) 34.5901 29.8127 5.0168 (d35) 28.9557 2.0339 23.2186 (d41) 6.6762 66.1129 66.1129 (BF) 1.0000 1.0000 1.0000 [Lens group data] Group starting plane focal length G1 1 257.3766 G2 7 142.3422 G3 10 -30.1478 G4 21 69.0603 G5 27 -92.0724 G6 30 122.9491 G7 33 101.9794 G8 36 -101.3136 G9 42 -293.7021 [Examples]

[0168] Figure 51 is a diagram of the lens configuration of the variable magnification imaging optical system according to Example 6 when it is focused at the wide-angle end and infinity.

[0169] The variable magnification imaging optical system in Figure 51 consists of, in order from the object side, a first lens group G1 with positive refractive power, a second lens group G2 with positive refractive power, a third lens group G3 with negative refractive power, a first intermediate group GM1 consisting of a fourth lens group G4 and a fifth lens group G5, a second intermediate group GM2 consisting of a sixth lens group G6 that moves along the optical axis when focusing from an object at infinity to an object at close range, and a subsequent group GR consisting of a seventh lens group G7, an eighth lens group G8, and a ninth lens group G9 that moves along the optical axis when focusing from an object at infinity to an object at close range.

[0170] Starting from the object side, the first lens group G1 consists of a concave meniscus lens with its convex surface facing the object, a biconvex lens, and a convex meniscus lens with its convex surface facing the object. The second lens group G2 consists of a cemented lens of a biconvex lens and a biconcave lens. The third lens group G3 consists of a biconvex lens, a concave meniscus lens with its convex surface facing the object, a cemented lens of a biconcave lens and a biconvex lens, and a cemented lens of a biconcave lens and a biconvex lens. Furthermore, the second to fourth lenses from the object side of the third lens group G3 can be moved as a single unit in a direction approximately perpendicular to the optical axis to function as an image stabilization group. The fourth lens group G4 consists of a biconvex lens, a cemented lens of a biconvex lens and a concave meniscus lens with its convex surface facing the image side, and an aperture diaphragm S. The fifth lens group G5 consists of a biconvex lens and a cemented lens of a biconvex lens and a biconcave lens. The sixth lens group G6 consists of a cemented lens made of a biconvex lens and a concave meniscus lens with its convex surface facing the image side. The seventh lens group G7 consists of a cemented lens made of a convex meniscus lens with its convex surface facing the image side and a biconcave lens. The eighth lens group G8 consists of a concave meniscus lens with its convex surface facing the object side and a cemented lens made of a biconvex lens and a biconcave lens. The ninth lens group G9 consists of a cemented lens made of a biconvex lens and a biconcave lens and a concave meniscus lens with its convex surface facing the image side.

[0171] When changing magnification from the wide-angle end to the telephoto end, the second lens group G2 and the ninth lens group G9 remain fixed relative to the image plane, the first lens group G1 moves toward the object, the third lens group G3 to the eighth lens group G8 each move toward the object, the distance between the first lens group G1 and the second lens group G2 increases, the distance between the second lens group G2 and the third lens group G3 decreases, the distance between the third lens group G3 and the fourth lens group G4 decreases, and the distance between the fourth lens group G4 and the fifth lens The spacing of lens group G5 decreases, the spacing between lens group G5 and lens group G6 increases, the spacing between lens group G6 and lens group G7 decreases, the spacing between lens group G7 and lens group G8 decreases, and the spacing between lens group G8 and lens group G9 increases. When focusing from an object at infinity to an object at close range, lens group G6 moves along the optical axis towards the object, and lens group G7 moves along the optical axis towards either the image or the object. Also, the amount of movement due to focusing from an object at infinity to the closest range at the telephoto end is greater for lens group G6 than for lens group G7 (however, the positive or negative direction of movement is not considered, and the comparison is made as a simple amount of movement).

[0172] The specifications of the variable magnification imaging optical system according to Example 6 are shown below. Numerical Example 6 Unit: mm [Surface data] Face number rd nd vd ΔPgF Applicable glass material 0 (d0) 1 404.9734 2.9999 1.55298 55.07 -0.0046 J-KZFH4 2 142.7479 0.0999 3 142.5136 10.8134 1.43875 94.66 0.0560 S-FPL55 4 -516.9418 0.2999 5 132.6564 6.9127 1.49700 81.54 0.0358 S-FPL51 6 315.8743 (d6) 7 246.8499 4.9474 1.85451 25.15 0.0071 NBFD25 8 -376.9692 1.6000 1.92286 18.90 0.0351 S-NPH2 9 852.0964 (d9) 10 345.5389 3.4744 1.53172 48.84 0.0025 S-TIL6 11 -137.4509 3.0000 12 843.9684 1.0000 1.85150 40.78 -0.0055 S-LAH89 13 82.0234 3.1953 14 -75.3119 1.0000 1.85150 40.78 -0.0055 S-LAH89 15 75.4351 3.7872 1.85451 25.15 0.0071 NBFD25 16 -423.6389 4.3443 17 -48.6820 1.0000 1.80400 46.53 -0.0070 S-LAH65VS 18 45.0953 5.2627 1.69895 30.13 0.0087 S-TIM35 19 -318.2078 (d19) 20 143.5763 4.4534 1.76385 48.49 -0.0022 S-LAH96 21 -101.2631 0.3000 22 62.7078 7.2896 1.43875 94.66 0.0560 S-FPL55 23 -51.0199 1.0000 1.77250 49.62 -0.0088 TAF1 24 -2852.4854 3.0000 25 (aperture) ∞ (d25) 26 134.2412 5.4326 1.49700 81.54 0.0358 S-FPL51 27 -61.9367 0.3000 28 38.1336 6.0536 1.43875 94.66 0.0560 S-FPL55 29 -161.4272 1.0000 1.77047 29.74 0.0002 NBFD29 30 40.2204 (d30) 31 59.0241 4.8537 1.69895 30.13 0.0087 S-TIM35 32 -40.2887 0.8999 1.95375 32.32 0.0003 S-LAH98 33 -150.4817 (d33) 34 -90.2327 2.6811 1.76182 26.52 0.0129 S-TIH14 35 -48.4183 1.0000 1.90525 35.04 -0.0005 S-LAH93 36 60.1209 (d36) 37 50.7573 0.8999 1.92286 18.90 0.0351 S-NPH2 38 26.9728 10.9417 1.77047 29.74 0.0002 NBFD29 39 -31.0511 0.9997 1.59522 67.73 0.0177 S-FPM2 40 111.4545 (d40) 41 90.7062 7.2714 1.61310 44.36 -0.0081 E-ADF10 42 -32.1297 0.9999 1.43875 94.66 0.0560 S-FPL55 43 108.4675 7.8763 44 -31.5068 1.1999 1.95375 32.32 0.0003 S-LAH98 45 -58.7369 34.4229 46 ∞ 2.5000 1.51680 64.20 0.0014 BSC7 47 ∞ (BF) [Various Data] Zoom ratio 4.05 Wide-angle (INF) Intermediate (INF) Telephoto (INF) Focal length 142.50 285.00 577.80 F-numbers: 4.71, 5.22, 6.48 Full angle of view 2ω 17.15 8.60 4.18 Image height Y 21.63 21.63 21.63 Lens length: 280.00 337.15 410.00 [Variable interval data] Wide-angle (INF) Wide-angle (close-up) Intermediate (INF) (d0) ∞ 2500.0000 ∞ (d6) 2.0000 2.0000 59.1503 (d9) 47.0124 47.0124 48.0601 (d19) 23.1953 23.1953 9.2986 (d25) 15.6239 15.6239 9.6661 (d30) 3.2907 2.6539 15.3007 (d33) 15.9987 17.8968 19.1161 (d36) 10.7665 9.5052 14.4459 (d40) 2.0000 2.0000 2.0000 (BF) 1.0000 1.0000 1.0000 Intermediate (close range) Telephoto (INF) Telephoto (close range) (d0) 2500.0000 ∞ 2500.0000 (d6) 59.1503 132.0000 132.0000 (d9) 48.0601 25.9556 25.9556 (d19) 9.2986 2.0000 2.0000 (d25) 9.6661 2.0000 2.0000 (d30) 6.8584 40.6770 23.9746 (d33) 26.4337 2.2861 22.2353 (d36) 15.5707 9.6785 6.4317 (d40) 2.0000 35.2902 35.2902 (BF) 1.0000 1.0000 1.0000 [Lens group data] Group starting plane focal length G1 1 276.9187 G2 7 452.1000 G3 10 -32.6424 G4 20 70.9354 G5 26 229.7636 G6 31 84.4731 G7 34 -37.3354 G8 37 77.4187 G9 41 -234.3111 [Examples]

[0173] Figure 61 is a diagram of the lens configuration of the variable magnification imaging optical system according to Example 7 when it is focused at the wide-angle end and infinity.

[0174] The variable magnification imaging optical system in Figure 61 consists of, in order from the object side, a first lens group G1 with positive refractive power, a second lens group G2 with positive refractive power, a third lens group G3 with negative refractive power, a first intermediate group GM1 consisting of a fourth lens group G4 and a fifth lens group G5, a second intermediate group GM2 consisting of a sixth lens group G6 that moves along the optical axis when focusing from an object at infinity to an object at close range, and a subsequent group GR consisting of a seventh lens group G7 and an eighth lens group G8.

[0175] Starting from the object side, the first lens group G1 consists of a concave meniscus lens with its convex surface facing the object, a convex meniscus lens with its convex surface facing the object, a biconvex lens, and a convex meniscus lens with its convex surface facing the object. The second lens group G2 consists of a cemented lens of a biconvex lens and a biconcave lens. The third lens group G3 consists of a concave meniscus lens with its convex surface facing the object, a cemented lens of a biconcave lens and a biconvex lens, and a cemented lens of a biconcave lens and a convex meniscus lens with its convex surface facing the object. Furthermore, the first to third lenses from the object side of the third lens group G3 can be moved as a single unit in a direction approximately perpendicular to the optical axis to function as an image stabilization group. The fourth lens group G4 consists of a biconvex lens, a cemented lens of a convex meniscus lens with its convex surface facing the object and a concave meniscus lens with its convex surface facing the object, a cemented lens of a biconvex lens and a concave meniscus lens with its convex surface facing the image, and an aperture diaphragm S. The fifth lens group G5 consists of a cemented lens of a concave meniscus lens with its convex surface facing the object and a convex meniscus lens with its convex surface facing the object, a biconvex lens, and a concave meniscus lens with its convex surface facing the object. The sixth lens group G6 consists of a cemented lens of a biconvex lens and a concave meniscus lens with its convex surface facing the image. The seventh lens group G7 consists of a cemented lens of a convex meniscus lens with its convex surface facing the image and a biconcave lens, a concave meniscus lens with its convex surface facing the object, and a cemented lens of a biconvex lens and a biconcave lens. The eighth lens group G8 consists of a cemented lens of a biconvex lens and a biconcave lens, and a concave meniscus lens with its convex surface facing the image.

[0176] When changing magnification from the wide-angle end to the telephoto end, the 8th lens group G8 is fixed relative to the image plane, the 1st lens group G1 moves toward the object, the 2nd lens group G2 moves toward the image, the 3rd lens group G3 moves toward the image, and the 4th lens group G4 to the 7th lens group G7 each move toward the object. The distance between the 1st lens group G1 and the 2nd lens group G2 increases, the distance between the 2nd lens group G2 and the 3rd lens group G3 decreases, the distance between the 3rd lens group G3 and the 4th lens group G4 decreases, the distance between the 4th lens group G4 and the 5th lens group G5 decreases, the distance between the 5th lens group G5 and the 6th lens group G6 increases, the distance between the 6th lens group G6 and the 7th lens group G7 decreases, and the distance between the 7th lens group G7 and the 8th lens group G8 increases. When focusing from an object at infinity to an object at close range, the 6th lens group G6 moves toward the object along the optical axis.

[0177] The specifications of the variable magnification imaging optical system according to Example 7 are shown below. Numerical Example 7 Unit: mm [Surface data] Face number rd nd vd ΔPgF Applicable glass material 0 (d0) 1 468.9940 2.9999 1.61340 44.27 -0.0054 S-NBM51 2 191.8524 0.0999 3 189.2793 11.0838 1.49700 81.54 0.0358 S-FPL51 4 8539.7183 0.2999 5 353.4077 7.7739 1.43875 94.66 0.0560 S-FPL55 6 -3586.7354 0.3000 7 207.2513 7.7999 1.43875 94.66 0.0560 S-FPL55 8 605.3550 (d8) 9 181.5597 9.6314 1.73800 32.33 -0.0002 S-NBH53V 10 -357.1647 1.9999 1.92286 20.88 0.0281 E-FDS1-W 11 1586.4867 (d11) 12 3518.9083 1.0000 1.95375 32.32 -0.0002 TAFD45 13 86.4889 4.3539 14 -94.6327 1.0000 1.76385 48.49 -0.0022 S-LAH96 15 65.3209 4.6702 1.85451 25.15 0.0071 NBFD25 16 -1065.5782 3.7813 17 -149.7539 1.0000 1.77250 49.62 -0.0088 TAF1 18 197.5002 2.7855 1.85451 25.15 0.0071 NBFD25 19 2710.8726 (d19) 20 345.8921 3.4952 1.86966 20.02 0.0310 FDS20-W 21 -180.5725 0.3000 22 42.0493 3.5691 1.43700 95.10 0.0564 FCD100 23 61.3703 1.0000 1.85451 25.15 0.0071 NBFD25 24 32.4590 0.9627 25 32.6384 10.0457 1.43700 95.10 0.0564 FCD100 26 -60.6146 1.0000 1.88300 40.80 -0.0094 TAFD30 27 -447.2285 3.0000 28 (aperture) ∞ (d28) 29 122.4993 1.0000 1.77250 49.62 -0.0088 TAF1 30 47.5746 5.5177 1.43700 95.10 0.0564 FCD100 31 904.5708 0.3000 32 109.8835 5.2299 1.63980 34.47 0.0059 S-TIM27 33 -79.9106 0.3000 34 149.9195 0.8994 1.85451 25.15 0.0071 NBFD25 35 58.1935 (d35) 36 58.2883 5.5965 1.59551 39.24 0.0026 S-TIM8 37 -86.1386 0.8998 1.89190 37.13 -0.0035 S-LAH92 38 -376.8660 (d38) 39 -121.4442 5.7595 1.74077 27.76 0.0093 E-FD13 40 -26.9456 1.0000 1.76385 48.49 -0.0022 S-LAH96 41 45.4111 1.5000 42 37.6247 1.0000 1.86966 20.02 0.0310 FDS20-W 43 25.3857 11.3292 1.61340 44.27 -0.0054 S-NBM51 44 -29.8919 0.9997 1.43700 95.10 0.0564 FCD100 45 127.9456 (d45) 46 357.9797 6.8723 1.61340 44.27 -0.0054 S-NBM51 47 -25.5489 1.0000 1.55032 75.50 0.0274 FCD705 48 148.6520 15.3045 49 -31.3188 0.9001 1.92286 20.88 0.0281 E-FDS1-W 50 -48.5764 33.5405 51 ∞ 2.5000 1.51680 64.20 0.0014 BSC7 52 ∞ (BF) [Various Data] Zoom ratio 3.88 Wide-angle (INF) Intermediate (INF) Telephoto (INF) Focal length 200.00 480.00 776.00 F-number 4.70 5.21 6.46 Full angle of view 2ω 12.05 5.04 3.12 Image height Y 21.63 21.63 21.63 Lens length: 360.00, 410.00, 470.00 [Variable interval data] Wide-angle (INF) Wide-angle (close-up) Intermediate (INF) (d0) ∞ 3200.0000 ∞ (d8) 2.0000 2.0000 99.9221 (d11) 60.4022 60.4022 40.0782 (d19) 57.5857 57.5857 4.6230 (d28) 20.5394 20.5394 21.0540 (d35) 5.7002 2.6430 29.3075 (d38) 23.0217 26.0789 26.1449 (d45) 4.3492 4.3492 2.4686 (BF) 1.0000 1.0000 1.0000 Intermediate (close range) Telephoto (INF) Telephoto (close range) (d0) 3200.0000 ∞ 3200.0000 (d8) 99.9221 183.4961 183.4961 (d11) 40.0782 2.0595 2.0595 (d19) 4.6230 2.0000 2.0000 (d28) 21.0540 2.0000 2.0000 (d35) 13.2507 46.0015 18.7796 (d38) 42.2017 3.5000 30.7219 (d45) 2.4686 44.5413 44.5413 (BF) 1.0000 1.0000 1.0000 [Lens group data] Group starting plane focal length G1 1 292.8770 G2 9 334.1784 G3 12 -43.9386 G4 20 135.4552 G5 29 262.0422 G6 36 109.0143 G7 39 -131.8489 G8 46 -104.9109 [Examples]

[0178] Figure 71 is a diagram of the lens configuration of the variable magnification imaging optical system according to Example 8 when it is focused at the wide-angle end and infinity.

[0179] The variable magnification imaging optical system in Figure 71 consists of, in order from the object side, a first lens group G1 with positive refractive power, a second lens group G2 with positive refractive power, a third lens group G3 with negative refractive power, a first intermediate group GM1 consisting of a fourth lens group G4 and a fifth lens group G5, a second intermediate group GM2 consisting of a sixth lens group G6 that moves along the optical axis when focusing from an object at infinity to an object at close range, and a subsequent group GR consisting of a seventh lens group G7 and an eighth lens group G8.

[0180] Starting from the object side, the first lens group G1 consists of a concave meniscus lens with its convex surface facing the object, a biconvex lens, and a convex meniscus lens with its convex surface facing the object. The second lens group G2 consists of a cemented lens of a concave meniscus lens with its convex surface facing the object and a convex meniscus lens with its convex surface facing the object, and a cemented lens of a biconvex lens and a biconcave lens. The third lens group G3 consists of a concave meniscus lens with its convex surface facing the object, a cemented lens of a biconcave lens and a biconvex lens, and a cemented lens of a biconcave lens and a convex meniscus lens with its convex surface facing the object. Furthermore, the first to third lenses from the object side of the third lens group G3 can be moved as a single unit in a direction approximately perpendicular to the optical axis to function as an anti-vibration group. The fourth lens group G4 consists of a biconvex lens, a cemented lens of a biconvex lens and a biconcave lens, and an aperture diaphragm S. The fifth lens group G5 consists of a cemented lens of a concave meniscus lens with its convex surface facing the object and a biconvex lens, and a cemented lens of a convex meniscus lens with its convex surface facing the object and a concave meniscus lens with its convex surface facing the object. The sixth lens group G6 consists of a cemented lens of a biconvex lens and a concave meniscus lens with its convex surface facing the image side. The seventh lens group G7 consists of a cemented lens of a convex meniscus lens with its convex surface facing the image side and a biconcave lens, and a cemented lens of a concave meniscus lens with its convex surface facing the object side, a biconvex lens and a biconcave lens. The eighth lens group G8 consists of a cemented lens of a biconvex lens and a biconcave lens, and a concave meniscus lens with its convex surface facing the image side.

[0181] When changing magnification from the wide-angle end to the telephoto end, the 8th lens group G8 is fixed relative to the image plane, the 1st lens group G1 moves toward the object, the 2nd lens group G2 moves toward the image, the 3rd lens group G3 moves toward the image, and the 4th lens group G4 to the 7th lens group G7 each move toward the object. The distance between the 1st lens group G1 and the 2nd lens group G2 increases, the distance between the 2nd lens group G2 and the 3rd lens group G3 decreases, the distance between the 3rd lens group G3 and the 4th lens group G4 decreases, the distance between the 4th lens group G4 and the 5th lens group G5 decreases, the distance between the 5th lens group G5 and the 6th lens group G6 increases, the distance between the 6th lens group G6 and the 7th lens group G7 decreases, and the distance between the 7th lens group G7 and the 8th lens group G8 increases. When focusing from an object at infinity to an object at close range, the 6th lens group G6 moves toward the object along the optical axis.

[0182] The specifications of the variable magnification imaging optical system according to Example 8 are shown below. Numerical Example 8 Unit: mm [Surface data] Face number rd nd vd ΔPgF Applicable glass material 0 (d0) 1 324.6183 3.0000 1.61340 44.27 -0.0054 S-NBM51 2 140.5122 0.1000 3 137.9804 10.2814 1.49700 81.61 0.0373 FCD1 4 -674.2358 0.3000 5 158.0802 6.8363 1.43700 95.10 0.0564 FCD100 6 567.0974 (d6) 7 348.8723 1.0000 1.84666 23.78 0.0136 FDS90-SG 8 66.8665 8.7935 1.61340 44.27 -0.0054 S-NBM51 9 701.4091 0.3000 10 96.8924 8.2978 1.69895 30.05 0.0084 E-FD15L 11 -246.0741 1.6000 1.59282 68.62 0.0192 FCD515 12 1246.7646 (d12) 13 266.3161 1.0000 1.77250 49.62 -0.0088 TAF1 14 67.6365 4.1477 15 -75.3165 1.0000 1.76385 48.49 -0.0022 S-LAH96 16 74.9572 3.8645 1.85451 25.15 0.0071 NBFD25 17 -592.9077 3.6241 18 -122.0328 1.0000 1.88202 37.22 -0.0045 MC-TAFD307 19 81.2206 3.2727 1.86966 20.02 0.0310 FDS20-W 20 445.8328 (d20) 21 79.8940 3.9316 1.51633 64.14 0.0023 S-BSL7 22 -585.6576 0.3000 23 64.6446 5.3019 1.43700 95.10 0.0564 FCD100 24 -113.8727 1.0000 1.77250 49.62 -0.0088 TAF1 25 413.9537 3.2601 26 (aperture) ∞ (d26) 27 49.4701 1.0000 1.70300 52.38 -0.0035 S-LAL21 28 32.9142 6.7453 1.43700 95.10 0.0564 FCD100 29 -155.1860 0.3000 30 25.8177 3.3529 1.49700 81.61 0.0373 FCD1 31 38.6903 0.8999 1.91082 35.25 -0.0028 TAFD35 32 25.0006 (d32) 33 45.3948 4.5497 1.54072 47.20 0.0043 E-FEL2 34 -49.8166 0.9000 1.91082 35.25 -0.0028 TAFD35 35 -130.2481 (d35) 36 -76.5812 2.6342 1.60342 38.01 0.0028 E-F5 37 -43.1027 1.0000 1.80420 46.50 -0.0075 TAF3D 38 49.0719 2.8399 39 155.7562 0.9998 1.43700 95.10 0.0564 FCD100 40 50.0876 7.1251 1.61340 44.27 -0.0054 S-NBM51 41 -22.2197 0.9998 1.43700 95.10 0.0564 FCD100 42 117.9144 (d42) 43 76.9150 7.6093 1.61340 44.27 -0.0054 S-NBM51 44 -27.7159 0.9998 1.55032 75.50 0.0274 FCD705 45 271.0147 4.9215 46 -42.4664 0.9000 1.92286 20.88 0.0281 E-FDS1-W 47 -79.9616 36.2848 48 ∞ 2.5000 1.51680 64.20 0.0014 BSC7 49 ∞ (BF) [Various Data] Zoom ratio 3.74 Wide-angle (INF) Intermediate (INF) Telephoto (INF) Focal length 154.50 300.00 577.80 F-numbers: 4.71, 5.23, 6.48 Full angle of view 2ω 15.63 8.04 4.18 Image height Y 21.63 21.63 21.63 Lens length: 275.00 334.54 380.00 [Variable interval data] Wide-angle (INF) Wide-angle (close-up) Intermediate (INF) (d0) ∞ 2450.0000 ∞ (d6) 2.2004 2.2004 80.8523 (d12) 31.9201 31.9201 21.3761 (d20) 43.2384 43.2384 20.7287 (d26) 14.8681 14.8681 15.2510 (d32) 6.1182 3.6782 17.8936 (d35) 14.8814 17.3214 11.4281 (d42) 2.0000 2.0000 7.2378 (BF) 1.0000 1.0000 1.0000 Intermediate (close range) Telephoto (INF) Telephoto (close range) (d0) 2450.0000 ∞ 2450.0000 (d6) 80.8523 145.7629 145.7629 (d12) 21.3761 2.5402 2.5402 (d20) 20.7287 2.0000 2.0000 (d26) 15.2510 2.0000 2.0000 (d32) 10.0816 34.2305 14.7308 (d35) 19.2401 3.5000 22.9996 (d42) 7.2378 30.1932 30.1932 (BF) 1.0000 1.0000 1.0000 [Lens group data] Group starting plane focal length G1 1 259.9946 G2 7 189.6140 G3 13 -37.1603 G4 21 105.2637 G5 27 204.3106 G6 33 87.1467 G7 36 -58.3507 G8 43 -961.1272 [Examples]

[0183] Figure 81 is a diagram of the lens configuration of the variable magnification imaging optical system according to Example 9 when it is focused at the wide-angle end and infinity.

[0184] The variable magnification imaging optical system in Figure 81 consists of, in order from the object side, a first lens group G1 with positive refractive power, a second lens group G2 with positive refractive power, a third lens group G3 with negative refractive power, a first intermediate group GM1 consisting of a fourth lens group G4 and a fifth lens group G5, a second intermediate group GM2 consisting of a sixth lens group G6 that moves along the optical axis when focusing from an object at infinity to an object at close range, and a subsequent group GR consisting of a seventh lens group G7 and an eighth lens group G8.

[0185] Starting from the object side, the first lens group G1 consists of a concave meniscus lens with its convex surface facing the object, a biconvex lens, and a convex meniscus lens with its convex surface facing the object. The second lens group G2 consists of a cemented lens of a biconvex lens and a biconcave lens. The third lens group G3 consists of a biconcave lens, a cemented lens of a biconcave lens and a biconvex lens, and a cemented lens of a biconcave lens and a convex meniscus lens with its convex surface facing the object. Furthermore, the first to third lenses of the third lens group G3 from the object side can be moved as a single unit in a direction approximately perpendicular to the optical axis to function as an image stabilization group. The fourth lens group G4 consists of a biconvex lens, a cemented lens of a biconvex lens and a concave meniscus lens with its convex surface facing the image side, and an aperture diaphragm S. The fifth lens group G5 consists of a biconvex lens and a cemented lens of a convex meniscus lens with its convex surface facing the object and a concave meniscus lens with its convex surface facing the object. The sixth lens group G6 consists of a cemented lens of a biconvex lens and a concave meniscus lens with its convex surface facing the image side. The seventh lens group G7 consists of a cemented lens of a convex meniscus lens with its convex surface facing the image side and a biconcave lens, and a cemented lens of a concave meniscus lens with its convex surface facing the object side and a biconvex lens and a biconcave lens. The eighth lens group G8 consists of a cemented lens of a biconvex lens and a biconcave lens, and a concave meniscus aspherical lens with its convex surface facing the image side and the image-side surface having a predetermined aspherical shape.

[0186] When changing magnification from the wide-angle end to the telephoto end, the 8th lens group G8 is fixed relative to the image plane, the 1st lens group G1 moves toward the object, the 2nd lens group G2 moves toward the image, the 3rd lens group G3 moves toward the image, and the 4th lens group G4 to the 7th lens group G7 each move toward the object. The distance between the 1st lens group G1 and the 2nd lens group G2 increases, the distance between the 2nd lens group G2 and the 3rd lens group G3 decreases, the distance between the 3rd lens group G3 and the 4th lens group G4 decreases, the distance between the 4th lens group G4 and the 5th lens group G5 decreases, the distance between the 5th lens group G5 and the 6th lens group G6 increases, the distance between the 6th lens group G6 and the 7th lens group G7 decreases, and the distance between the 7th lens group G7 and the 8th lens group G8 increases. When focusing from an object at infinity to an object at close range, the 6th lens group G6 moves toward the object along the optical axis.

[0187] The specifications of the variable magnification imaging optical system according to Example 9 are shown below. Numerical Example 9 Unit: mm [Surface data] Face number rd nd vd ΔPgF Applicable glass material 0 (d0) 1 390.4639 2.9999 1.61310 44.36 -0.0081 E-ADF10 2 141.0401 0.0999 3 139.6144 10.0607 1.49700 81.54 0.0358 S-FPL51 4 -877.3396 0.3000 5 153.3861 7.8915 1.43875 94.66 0.0560 S-FPL55 6 1156.8675 (d6) 7 170.2119 5.1347 1.75520 27.53 0.0102 E-FD4 8 -306.0893 1.6000 1.92286 20.88 0.0281 E-FDS1-W 9 434.5352 (d9) 10 -1117.3774 1.0000 1.91082 35.25 -0.0028 TAFD35 11 81.2891 3.4920 12 -72.5626 1.0000 1.80420 46.50 -0.0075 TAF3D 13 145.8122 4.0762 1.85451 25.15 0.0071 NBFD25 14 -93.1796 3.1130 15 -79.6029 1.0000 1.76385 48.49 -0.0022 S-LAH96 16 64.8769 3.6561 1.85451 25.15 0.0071 NBFD25 17 438.0363 (d17) 18 243.7252 3.8163 1.76385 48.49 -0.0022 S-LAH96 19 -106.1020 0.3000 20 74.1966 5.9555 1.43700 95.10 0.0564 FCD100 21 -62.5098 1.0000 1.77250 49.62 -0.0088 TAF1 22 -5727.8348 3.0000 23 (aperture) ∞ (d23) 24 75.4152 4.8007 1.43700 95.10 0.0564 FCD100 25 -116.7860 0.3000 26 30.4058 4.8626 1.49700 81.61 0.0373 FCD1 27 98.8187 1.0000 1.90525 35.04 -0.0005 S-LAH93 28 30.2436 (d28) 29 50.5125 5.7402 1.51742 52.15 0.0044 E-CF6 30 -45.4296 0.9001 1.85150 40.78 -0.0055 S-LAH89 31 -85.8852 (d31) 32 -387.8503 3.6425 1.85451 25.15 0.0071 NBFD25 33 -45.0783 1.0000 1.90525 35.04 -0.0005 S-LAH93 34 54.1152 3.1963 35 273.8144 1.0000 1.76385 48.49 -0.0022 S-LAH96 36 25.5281 10.4123 1.74330 49.22 -0.0104 NBF1 37 -23.3055 0.9999 1.59282 68.62 0.0192 FCD515 38 177.2352 (d38) 39 73.9776 7.9266 1.61310 44.36 -0.0081 E-ADF10 40 -26.3024 0.9999 1.59282 68.62 0.0192 FCD515 41 190.4267 6.3085 42 -29.3303 1.1997 1.85135 40.10 -0.0067 M-TAFD305 *43 -44.2911 35.1327 44 ∞ 2.5000 1.51680 64.20 0.0014 BSC7 45 ∞ (BF) [Aspherical data] 43 sides K 0.00000 A4 -1.48248E-06 A6 8.56692E-11 A8 -9.05631E-12 A10 1.52818E-14 A12 0.00000E+00 [Various Data] Zoom ratio 7.01 Wide-angle (INF) Intermediate (INF) Telephoto (INF) Focal length 82.40 285.00 577.80 F-numbers: 4.71, 5.22, 6.47 Full angle of view 2ω 30.29 8.53 4.18 Image height Y 21.63 21.63 21.63 Lens length: 290.00 329.01 400.00 [Variable interval data] Wide-angle (INF) Wide-angle (close-up) Intermediate (INF) (d0) ∞ 2500.0000 ∞ (d6) 2.0000 2.0000 78.6839 (d9) 23.2786 23.2786 41.2241 (d17) 60.3272 60.3272 15.3287 (d23) 29.2904 29.2904 2.0000 (d28) 12.6251 11.8747 9.4363 (d31) 8.0609 8.8114 14.2761 (d38) 2.0000 2.0000 15.6417 (BF) 1.0000 1.0000 1.0000 Intermediate (close range) Telephoto (INF) Telephoto (close range) (d0) 2500.0000 ∞ 2500.0000 (d6) 78.6839 162.0425 162.0425 (d9) 41.2241 2.3812 2.3812 (d17) 15.3287 2.0000 2.0000 (d23) 2.0000 2.0000 2.0000 (d28) 3.2835 48.4987 29.3127 (d31) 20.4289 3.5000 22.6860 (d38) 15.6417 27.1599 27.1599 (BF) 1.0000 1.0000 1.0000 [Lens group data] Group starting plane focal length G1 1 261.9536 G2 7 553.4500 G3 10 -40.3177 G4 18 88.6205 G5 24 355.9694 G6 29 78.8055 G7 32 -69.5813 G8 39 -375.7864 [Examples]

[0188] Figure 91 is a diagram of the lens configuration of the variable magnification imaging optical system according to Example 10 when it is focused at the wide-angle end and infinity.

[0189] The variable magnification imaging optical system in Figure 91 consists of, in order from the object side, a first lens group G1 with positive refractive power, a second lens group G2 with positive refractive power, a third lens group G3 with negative refractive power, a first intermediate group GM1 consisting of a fourth lens group G4 and a fifth lens group G5, a second intermediate group GM2 consisting of a sixth lens group G6 that moves along the optical axis when focusing from an object at infinity to an object at close range, and a subsequent group GR consisting of a seventh lens group G7 and an eighth lens group G8.

[0190] Starting from the object side, the first lens group G1 consists of a concave meniscus lens with its convex surface facing the object, a convex meniscus lens with its convex surface facing the object, a biconvex lens, and a convex meniscus lens with its convex surface facing the object. The second lens group G2 consists of a cemented lens of a biconvex lens and a biconcave lens. The third lens group G3 consists of a biconvex lens, a biconcave lens, a cemented lens of a biconcave lens and a convex meniscus lens with its convex surface facing the object, and a cemented lens of a biconcave lens and a convex meniscus lens with its convex surface facing the object. Furthermore, the second to fourth lenses from the object side of the third lens group G3 can be moved as a single unit perpendicular to the optical axis to function as an image stabilization group. The fourth lens group G4 consists of a biconvex lens, a cemented lens of a biconvex lens and a biconcave lens, a cemented lens of a biconvex lens and a concave meniscus lens with its convex surface facing the image, and an aperture diaphragm S. The fifth lens group G5 consists of a cemented lens of a concave meniscus lens with its convex surface facing the object and a convex meniscus lens with its convex surface facing the object, a biconvex lens, and a concave meniscus lens with its convex surface facing the object. The sixth lens group G6 consists of a cemented lens of a biconvex lens and a biconcave lens. The seventh lens group G7 consists of a cemented lens of a convex meniscus lens with its convex surface facing the image and a biconcave lens, a concave meniscus lens with its convex surface facing the object, and a cemented lens of a biconvex lens and a biconcave lens. The eighth lens group G8 consists of a cemented lens of a convex meniscus lens with its convex surface facing the image and a concave meniscus lens with its convex surface facing the image, and a concave meniscus aspherical lens with its convex surface facing the image and the image-side surface having a predetermined aspherical shape.

[0191] When changing magnification from the wide-angle end to the telephoto end, the 8th lens group G8 is fixed relative to the image plane, the 1st lens group G1 moves toward the object, the 2nd lens group G2 moves toward the image, the 3rd lens group G3 moves toward the image, and the 4th lens group G4 to the 7th lens group G7 each move toward the object. The distance between the 1st lens group G1 and the 2nd lens group G2 increases, the distance between the 2nd lens group G2 and the 3rd lens group G3 decreases, the distance between the 3rd lens group G3 and the 4th lens group G4 decreases, the distance between the 4th lens group G4 and the 5th lens group G5 decreases, the distance between the 5th lens group G5 and the 6th lens group G6 increases, the distance between the 6th lens group G6 and the 7th lens group G7 decreases, and the distance between the 7th lens group G7 and the 8th lens group G8 increases. When focusing from an object at infinity to an object at close range, the 6th lens group G6 moves toward the object along the optical axis.

[0192] The specifications of the variable magnification imaging optical system according to Example 10 are shown below. Numerical Example 10 Unit: mm [Surface data] Face number rd nd vd ΔPgF Applicable glass material 0 (d0) 1 425.1371 2.9999 1.61340 44.27 -0.0054 S-NBM51 2 182.7778 0.0998 3 180.8148 11.0084 1.49700 81.54 0.0358 S-FPL51 4 2162.6461 0.2999 5 363.5799 7.8479 1.43875 94.66 0.0560 S-FPL55 6 -2564.6623 0.3000 7 210.2580 7.8719 1.43875 94.66 0.0560 S-FPL55 8 644.7379 (d8) 9 169.2274 8.3708 1.85026 32.27 0.0026 S-LAH71 10 -833.5870 1.9987 1.92286 20.88 0.0281 E-FDS1-W 11 431.7262 (d11) 12 462.8454 3.5640 1.84666 23.78 0.0136 FDS90-SG 13 -204.0706 2.5657 14 -166.5873 1.0000 1.90525 35.04 -0.0005 S-LAH93 15 70.7633 4.1051 16 -228.4537 1.0000 1.60562 43.71 0.0023 S-BAM4 17 45.8915 5.8856 1.85451 25.15 0.0071 NBFD25 18 2110.6678 4.5031 19 -96.6205 1.0000 1.90525 35.04 -0.0005 S-LAH93 20 101.1779 3.4172 1.74950 35.28 0.0021 S-LAM7 21 702.4532 (d21) 22 126.3975 4.5312 1.85451 25.15 0.0071 NBFD25 23 -152.5754 2.5000 24 70.4290 5.1570 1.49700 81.61 0.0373 FCD1 25 -186.4304 1.0000 1.74951 35.33 -0.0030 S-NBH51 26 53.8046 3.5188 27 54.7492 7.4790 1.43700 95.10 0.0564 FCD100 28 -54.4798 1.0000 1.91082 35.25 -0.0028 TAFD35 29 -521.9889 3.0000 30 (aperture) (d30) 31 56.2396 1.0000 1.90366 31.31 0.0027 TAFD25 32 38.5480 6.0947 1.43700 95.10 0.0564 FCD100 33 504.5929 10.0617 34 95.6338 4.8381 1.57135 52.95 0.0023 S-BAL3 35 -95.7409 0.5526 36 80.2094 0.8999 1.85150 40.78 -0.0055 S-LAH89 37 40.2550 (d37) 38 51.5327 5.1725 1.64769 33.84 0.0049 E-FD2 39 -104.5697 0.8998 1.90525 35.04 -0.0005 S-LAH93 40 1302.4788 (d40) 41 -145.0875 6.0005 1.73037 32.23 -0.0005 NBFD32 42 -24.4762 1.0000 1.76385 48.49 -0.0022 S-LAH96 43 35.3149 1.5000 44 30.8617 1.0000 1.92286 20.88 0.0281 E-FDS1-W 45 22.2062 11.9993 1.61340 44.27 -0.0054 S-NBM51 46 -26.8076 0.9997 1.43700 95.10 0.0564 FCD100 47 107.9779 (d47) 48 -362.7586 7.0547 1.61310 44.36 -0.0081 E-ADF10 49 -24.0120 0.9998 1.43700 95.10 0.0564 FCD100 50 -66.6605 4.1502 51 -31.9058 0.9000 1.76802 49.24 -0.0082 M-TAF101 *52 -251.0104 37.4794 53 ∞ 2.5000 1.51680 64.20 0.0014 BSC7 54 ∞ (BF) [Aspherical data] 52 pages K 0.00000 A4 -4.54607E-07 A6 2.33485E-09 A8 5.63788E-12 A10 -8.22774E-14 A12 2.45074E-16 [Various Data] Zoom ratio 3.88 Wide-angle (INF) Intermediate (INF) Telephoto (INF) Focal length 200.00 480.00 776.00 F-number 4.70 5.21 6.46 Full angle of view 2ω 12.07 5.05 3.12 Image height Y 21.63 21.63 21.63 Lens length: 360.00, 410.00, 470.00 [Variable interval data] Wide-angle (INF) Wide-angle (close-up) Intermediate (INF) (d0) ∞ 3200.0000 ∞ (d8) 2.0000 2.0000 93.8698 (d11) 53.5563 53.5563 36.7465 (d21) 53.3750 53.3750 2.0000 (d30) 14.9669 14.9669 16.7107 (d37) 6.0514 2.7368 27.8252 (d40) 23.5806 26.8951 27.5602 (d47) 4.3431 4.3431 3.1608 (BF) 1.0000 1.0000 1.0000 Intermediate (close range) Telephoto (INF) Telephoto (close range) (d0) 3200.0000 ∞ 3200.0000 (d8) 93.8698 175.0342 175.0342 (d11) 36.7465 2.0565 2.0565 (d21) 2.0000 2.0000 2.0000 (d30) 16.7107 2.0000 2.0000 (d37) 10.6881 38.3157 10.1837 (d40) 44.6973 3.5000 31.6320 (d47) 3.1608 44.9669 44.9669 (BF) 1.0000 1.0000 1.0000 [Lens group data] Group starting plane focal length G1 1 296.9228 G2 9 349.5032 G3 12 -43.8433 G4 22 144.9743 G5 31 200.0783 G6 38 104.8392 G7 41 -116.2129 G8 48 -129.5249 [Examples]

[0193] Figure 101 is a diagram of the lens configuration of the variable magnification imaging optical system according to Example 11 when it is focused at the wide-angle end and infinity.

[0194] The variable magnification imaging optical system in Figure 101 consists of, in order from the object side, a first lens group G1 with positive refractive power, a second lens group G2 with positive refractive power, a third lens group G3 with negative refractive power, a first intermediate group GM1 consisting of a fourth lens group G4 and a fifth lens group G5, a second intermediate group GM2 consisting of a sixth lens group G6 that moves along the optical axis when focusing from an object at infinity to an object at close range, and a subsequent group GR consisting of a seventh lens group G7, an eighth lens group G8, and a ninth lens group G9 that moves along the optical axis when focusing from an object at infinity to an object at close range.

[0195] Starting from the object side, the first lens group G1 consists of a concave meniscus lens with its convex surface facing the object, a biconvex lens, and a convex meniscus lens with its convex surface facing the object. The second lens group G2 consists of a cemented lens of a biconvex lens and a concave meniscus lens with its convex surface facing the image side. The third lens group G3 consists of a concave meniscus lens with its convex surface facing the object, a cemented lens of a biconcave lens and a biconvex lens, and a cemented lens of a biconcave lens and a convex meniscus lens with its convex surface facing the object side. Furthermore, the first to third lenses of the third lens group G3 from the object side can be moved as a single unit in a direction approximately perpendicular to the optical axis to function as an image stabilization group. The fourth lens group G4 consists of a biconvex lens, a cemented lens of a biconvex lens and a concave meniscus lens with its convex surface facing the image side, and an aperture diaphragm S. The fifth lens group G5 consists of a biconvex lens and a cemented lens of a convex meniscus lens with its convex surface facing the object and a concave meniscus lens with its convex surface facing the object. The sixth lens group G6 consists of a biconvex lens and a cemented lens of a concave meniscus lens with its convex surface facing the image. The seventh lens group G7 consists of a cemented lens of a convex meniscus lens with its convex surface facing the image and a biconcave lens. The eighth lens group G8 consists of a concave meniscus lens with its convex surface facing the object and a cemented lens of a biconvex lens and a biconcave lens. The ninth lens group G9 consists of a cemented lens of a biconvex lens and a concave meniscus lens with its convex surface facing the image and a concave meniscus aspherical lens with its convex surface facing the image and the image-side surface having a predetermined aspherical shape.

[0196] When changing magnification from the wide-angle end to the telephoto end, the 9th lens group G9 is fixed relative to the image plane, the 1st lens group G1 moves toward the object, the 2nd lens group G2 moves toward the image, the 3rd lens group G3 moves toward the image, and the 4th lens group G4 to the 8th lens group G8 each move toward the object. The distance between the 1st lens group G1 and the 2nd lens group G2 increases, the distance between the 2nd lens group G2 and the 3rd lens group G3 decreases, and the distance between the 3rd lens group G3 and the 4th lens group G4 decreases. As a result, the distance between the fourth lens group G4 and the fifth lens group G5 decreases, the distance between the fifth lens group G5 and the sixth lens group G6 increases, the distance between the sixth lens group G6 and the seventh lens group G7 decreases, the distance between the seventh lens group G7 and the eighth lens group G8 increases, and the distance between the eighth lens group G8 and the ninth lens group G9 increases. When focusing from an object at infinity to an object at close range, the sixth lens group G6 moves along the optical axis toward the object, and the seventh lens group G7 moves toward the image. Also, the amount of movement due to focusing from an object at infinity to the closest range at the telephoto end is greater for the sixth lens group G6 than for the seventh lens group G7 (however, the positive or negative direction of movement is not considered, and the comparison is made as a simple amount of movement).

[0197] The specifications of the variable magnification imaging optical system according to Example 11 are shown below. Numerical Example 11 Unit: mm [Surface data] Face number rd nd vd ΔPgF Applicable glass material 0 (d0) 1 430.4436 3.0000 1.61310 44.36 -0.0081 E-ADF10 2 153.0257 0.1000 3 153.0275 8.8289 1.49700 81.54 0.0358 S-FPL51 4 -1334.9829 0.3000 5 145.1461 7.9542 1.43875 94.66 0.0560 S-FPL55 6 769.1863 (d6) 7 156.7769 8.4524 1.67300 38.26 -0.0038 S-NBH52V 8 -106.6504 1.6000 2.00069 25.46 0.0110 TAFD40-W 9 -232.2673 (d9) 10 9681.9688 1.0000 1.90525 35.04 -0.0005 S-LAH93 11 83.4849 4.0755 12 -69.6206 1.0000 1.76385 48.49 -0.0022 S-LAH96 13 64.8572 4.4249 1.85451 25.15 0.0071 NBFD25 14 -243.5612 3.4317 15 -103.9254 1.0000 1.77250 49.62 -0.0088 TAF1 16 68.8704 3.1445 1.85451 25.15 0.0071 NBFD25 17 177.8319 (d17) 18 186.5260 3.8381 1.64769 33.79 0.0063 S-TIM22 19 -122.3023 0.3000 20 74.2491 5.7819 1.43700 95.10 0.0564 FCD100 21 -71.9933 1.0000 1.77250 49.62 -0.0088 TAF1 22 -1965.5343 3.0000 23 (aperture) ∞ (d23) 24 52.8950 5.5913 1.43700 95.10 0.0564 FCD100 25 -143.8818 0.3000 26 41.4393 4.6221 1.49700 81.61 0.0373 FCD1 27 324.8839 1.0000 1.85451 25.15 0.0071 NBFD25 28 39.9899 (d28) 29 62.3571 5.0833 1.62004 36.26 0.0048 S-TIM2 30 -37.2181 0.9000 1.90525 35.04 -0.0005 S-LAH93 31 -107.4436 (d31) 32 -155.9203 3.4367 1.76182 26.61 0.0117 FD140 33 -38.9722 1.0000 1.76385 48.49 -0.0022 S-LAH96 34 90.9728 (d34) 35 6516.4207 1.0000 1.91082 35.25 -0.0028 TAFD35 36 29.0208 10.1977 1.74330 49.22 -0.0104 NBF1 37 -23.2861 1.0000 1.59282 68.62 0.0192 FCD515 38 59.5093 (d38) 39 45.7292 9.6411 1.61310 44.36 -0.0081 E-ADF10 40 -25.5828 1.0000 1.53775 74.70 0.0254 S-FPM3 41 -215.0370 8.9358 42 -29.8831 1.1999 1.85135 40.10 -0.0067 M-TAFD305 *43 -61.1541 35.6839 44 ∞ 2.5000 1.51680 64.20 0.0014 BSC7 45 ∞ (BF) [Aspherical data] 43 sides K 0.00000 A4 -8.13524E-07 A6 -3.67046E-09 A8 9.65368E-12 A10 -1.65331E-14 A12 0.00000E+00 [Various Data] Zoom ratio 7.01 Wide-angle (INF) Intermediate (INF) Telephoto (INF) Focal length 82.40 285.00 577.80 F-numbers: 4.71, 5.23, 6.48 Full angle of view 2ω 29.82 8.52 4.18 Image height Y 21.63 21.63 21.63 Lens length: 290.00 x 345.69 x 400.25 [Variable interval data] Wide-angle (INF) Wide-angle (close-up) Intermediate (INF) (d0) ∞ 2500.0000 ∞ (d6) 2.0000 2.0000 99.0473 (d9) 16.6944 16.6944 21.5139 (d17) 68.1843 68.1843 17.5157 (d23) 16.3786 16.3786 4.4105 (d28) 16.9391 16.2225 18.4492 (d31) 2.6289 3.4454 14.0736 (d34) 8.8508 8.7508 4.2351 (d38) 2.0000 2.0000 10.1181 (BF) 1.0000 1.0000 1.0000 Intermediate (close range) Telephoto (INF) Telephoto (close range) (d0) 2500.0000 ∞ 2500.0000 (d6) 99.0473 149.1147 149.1147 (d9) 21.5139 14.6944 14.6944 (d17) 17.5157 2.0000 2.0000 (d23) 4.4105 2.0000 2.0000 (d28) 12.3436 34.7722 22.7780 (d31) 21.7902 2.0000 23.8753 (d34) 2.6242 35.5910 25.7098 (d38) 10.1181 3.7511 3.7511 (BF) 1.0000 1.0000 1.0000 [Lens group data] Group starting plane focal length G1 1 286.7602 G2 7 181.9090 G3 10 -33.3910 G4 18 94.5715 G5 24 203.2806 G6 29 93.7054 G7 32 -74.4126 G8 35 -108.2166 G9 39 132.2344 [Examples]

[0198] Figure 111 is a diagram of the lens configuration of the variable magnification imaging optical system according to Example 12 when it is focused at the wide-angle end and infinity.

[0199] The variable magnification imaging optical system in Figure 111 consists of, in order from the object side, a first lens group G1 with positive refractive power, a second lens group G2 with positive refractive power, a third lens group G3 with negative refractive power, a first intermediate group GM1 consisting of a fourth lens group G4 and a fifth lens group G5, a second intermediate group GM2 consisting of a sixth lens group G6 that moves along the optical axis when focusing from an object at infinity to an object at close range, and a subsequent group GR consisting of a seventh lens group G7, an eighth lens group G8, and a ninth lens group G9 that moves along the optical axis when focusing from an object at infinity to an object at close range.

[0200] Starting from the object side, the first lens group G1 consists of a concave meniscus lens with its convex surface facing the object, a convex meniscus lens with its convex surface facing the object, a biconvex lens, and a convex meniscus lens with its convex surface facing the object. The second lens group G2 consists of a cemented lens of a biconvex lens and a biconcave lens. The third lens group G3 consists of a biconvex lens, a biconcave lens, a cemented lens of a biconcave lens and a biconvex lens, and a cemented lens of a biconcave lens and a convex meniscus lens with its convex surface facing the object. Furthermore, the second to fourth lenses from the object side of the third lens group G3 can be moved as a single unit in a direction approximately perpendicular to the optical axis to function as an image stabilization group. The fourth lens group G4 consists of a biconvex lens, a cemented lens of a biconvex lens and a biconcave lens, a cemented lens of a biconvex lens and a concave meniscus lens with its convex surface facing the image side, and an aperture diaphragm S. The fifth lens group G5 consists of a cemented lens of a concave meniscus lens with its convex surface facing the object and a convex meniscus lens with its convex surface facing the object, a biconvex lens, and a concave meniscus lens with its convex surface facing the object. The sixth lens group G6 consists of a cemented lens of a biconvex lens and a concave meniscus lens with its convex surface facing the image. The seventh lens group G7 consists of a cemented lens of a convex meniscus lens with its convex surface facing the image and a biconcave lens. The eighth lens group G8 consists of a cemented lens of a concave meniscus lens with its convex surface facing the object, a biconvex lens, and a biconcave lens. The ninth lens group G9 consists of a cemented lens of a convex meniscus lens with its convex surface facing the image and a concave meniscus lens with its convex surface facing the image, and a concave meniscus aspherical lens with its convex surface facing the image and the image-side surface having a predetermined aspherical shape.

[0201] When changing magnification from the wide-angle end to the telephoto end, the 9th lens group G9 is fixed relative to the image plane, the 1st lens group G1 moves toward the object, the 2nd lens group G2 moves toward the image, the 3rd lens group G3 moves toward the image, and the 4th lens group G4 to the 8th lens group G8 each move toward the object. The distance between the 1st lens group G1 and the 2nd lens group G2 increases, the distance between the 2nd lens group G2 and the 3rd lens group G3 decreases, and the distance between the 3rd lens group G3 and the 4th lens group G4 decreases. As a result, the distance between the fourth lens group G4 and the fifth lens group G5 decreases, the distance between the fifth lens group G5 and the sixth lens group G6 increases, the distance between the sixth lens group G6 and the seventh lens group G7 decreases, the distance between the seventh lens group G7 and the eighth lens group G8 increases, and the distance between the eighth lens group G8 and the ninth lens group G9 increases. When focusing from an object at infinity to an object at close range, the sixth lens group G6 moves along the optical axis toward the object, and the seventh lens group G7 moves toward the image. Also, the amount of movement due to focusing from an object at infinity to the closest range at the telephoto end is greater for the sixth lens group G6 than for the seventh lens group G7 (however, the positive or negative direction of movement is not considered, and the comparison is made as a simple amount of movement).

[0202] The specifications of the variable magnification imaging optical system according to Example 12 are shown below. Numerical Example 12 Unit: mm [Surface data] Face number rd nd vd ΔPg Applicable glass material 0 (d0) 1 431.1270 3.0000 1.61340 44.27 -0.0054 S-NBM51 2 181.9466 0.1000 3 180.1850 10.7003 1.49700 81.54 0.0358 S-FPL51 4 1479.9676 0.3000 5 347.7994 7.9768 1.43875 94.66 0.0560 S-FPL55 6 -3075.9801 0.3000 7 218.4111 7.9940 1.43875 94.66 0.0560 S-FPL55 8 762.3353 (d8) 9 187.2661 7.9232 1.90525 35.04 -0.0005 S-LAH93 10 -599.2238 1.9999 1.92286 20.88 0.0281 E-FDS1-W 11 522.7831 (d11) 12 315.1100 3.5012 1.84666 23.78 0.0136 FDS90-SG 13 -265.2081 2.5468 14 -217.7296 1.0000 1.90525 35.04 -0.0005 S-LAH93 15 77.9726 4.5386 16 -118.1366 1.0000 1.61772 49.81 0.0015 S-BSM28 17 56.2581 5.1605 1.85451 25.15 0.0071 NBFD25 18 -1987.3990 4.1802 19 -111.4815 1.0000 1.90525 35.04 -0.0005 S-LAH93 20 82.7212 3.9140 1.73800 32.33 -0.0002 S-NBH53V 21 2638.0233 (d21) 22 108.8250 4.3550 1.84666 23.78 0.0136 FDS90-SG 23 -218.2370 2.5000 24 59.3721 5.1718 1.49700 81.61 0.0373 FCD1 25 -325.6574 1.0000 1.80100 34.97 0.0009 S-LAM66 26 40.0887 0.6910 27 37.4470 8.5525 1.43700 95.10 0.0564 FCD100 28 -54.8675 1.0000 1.88300 40.80 -0.0094 TAFD30 29 -428.1340 3.0000 30 (aperture) ∞ (d30) 31 81.6569 1.0000 1.91082 35.25 -0.0028 TAFD35 32 37.6388 4.6711 1.43700 95.10 0.0564 FCD100 33 99.3214 0.3000 34 52.5577 6.7115 1.56732 42.84 0.0030 E-FL6 35 -80.7339 0.3000 36 96.1165 0.8997 1.85451 25.15 0.0071 NBFD25 37 50.9512 (d37) 38 60.7387 6.0297 1.72047 34.71 -0.0025 S-NBH8 39 -64.2703 0.8998 1.90525 35.04 -0.0005 S-LAH93 40 -1093.4038 (d40) 41 -2443.5531 5.5707 1.69895 30.05 0.0084 E-FD15L 42 -30.1155 1.0000 1.76385 48.49 -0.0022 S-LAH96 43 39.3188 (d43) 44 33.0380 1.0000 1.92286 20.88 0.0281 E-FDS1-W 45 23.1233 10.9939 1.61310 44.36 -0.0081 E-ADF10 46 -33.0619 0.9998 1.43700 95.10 0.0564 FCD100 47 49.1026 (d47) 48 -1271.4825 7.1200 1.61310 44.36 -0.0081 E-ADF10 49 -24.4175 1.0000 1.43700 95.10 0.0564 FCD100 50 -214.2543 5.8377 51 -31.3521 0.9000 1.85135 40.10 -0.0067 MC-TAFD305 *52 -89.1776 34.7439 53 ∞ 2.5000 1.51680 64.20 0.0014 BSC7 54 ∞ (BF) [Aspherical data] 52 pages K 0.00000 A4 -6.27946E-07 A6 1.41635E-09 A8 2.34641E-11 A10 -1.62795E-13 A12 3.65714E-16 [Various Data] Zoom ratio 3.88 Wide-angle (INF) Intermediate (INF) Telephoto (INF) Focal length 200.00 480.00 776.00 F-number 4.70 5.21 6.46 Full angle of view 2ω 12.05 5.06 3.12 Image height Y 21.63 21.63 21.63 Lens length: 359.00, 410.00, 470.00 [Variable interval data] Wide-angle (INF) Wide-angle (close-up) Intermediate (INF) (d0) ∞ 3200.0000 ∞ (d8) 3.5552 3.5552 96.0943 (d11) 50.6835 50.6835 36.7990 (d21) 52.6303 52.6303 2.0000 (d30) 26.9278 26.9278 24.0712 (d37) 3.9763 2.4691 28.6302 (d40) 25.0430 28.0831 22.5285 (d43) 5.3755 3.8427 6.8031 (d47) 3.9249 3.9249 6.1903 (BF) 1.0000 1.0000 1.0000 Intermediate (close range) Telephoto (INF) Telephoto (close range) (d0) 3200.0000 ∞ 3200.0000 (d8) 96.0943 180.9445 180.9445 (d11) 36.7990 2.0000 2.0000 (d21) 2.0000 2.0000 2.0000 (d30) 24.0712 2.0000 2.0000 (d37) 13.9401 47.5622 22.9177 (d40) 38.2186 2.0000 29.1446 (d43) 5.8031 6.0000 3.4999 (d47) 6.1903 40.6099 40.6099 (BF) 1.0000 1.0000 1.0000 [Lens group data] Group starting plane focal length G1 1 304.0603 G2 9 324.2267 G3 12 -46.1624 G4 22 152.3249 G5 31 227.1077 G6 38 101.0496 G7 41 -45.6301 G8 44 85.5463 G9 48 -128.171 [Examples]

[0203] Figure 121 is a diagram of the lens configuration of the variable magnification imaging optical system according to Example 13 when it is focused at the wide-angle end and infinity.

[0204] The variable magnification imaging optical system in Figure 121 consists of, in order from the object side, a first lens group G1 with positive refractive power, a second lens group G2 with positive refractive power, a third lens group G3 with negative refractive power, a first intermediate group GM1 consisting of a fourth lens group G4 and a fifth lens group G5, a second intermediate group GM2 consisting of a sixth lens group G6 that moves along the optical axis when focusing from an object at infinity to an object at close range, and a subsequent group GR consisting of a seventh lens group G7 and an eighth lens group G8.

[0205] Starting from the object side, the first lens group G1 consists of a concave meniscus lens with its convex surface facing the object, a biconvex lens, and a convex meniscus lens with its convex surface facing the object. The second lens group G2 consists of a cemented lens of a biconcave lens and a biconvex lens, and a cemented lens of a biconvex lens and a concave meniscus lens with its convex surface facing the image side. The third lens group G3 consists of a biconvex lens, a concave meniscus lens with its convex surface facing the object, a cemented lens of a biconcave lens and a biconvex lens, and a cemented lens of a biconcave lens and a convex meniscus lens with its convex surface facing the object side. Furthermore, the second to fourth lenses from the object side of the third lens group G3 can be moved as a single unit in a direction approximately perpendicular to the optical axis to function as an image stabilization group. The fourth lens group G4 consists of a biconvex lens, a cemented lens of a biconvex lens and a concave meniscus lens with its convex surface facing the image side, and an aperture diaphragm S. The fifth lens group G5 consists of a cemented lens of a concave meniscus lens with its convex surface facing the object and a biconvex lens, and a cemented lens of a convex meniscus lens with its convex surface facing the object and a concave meniscus lens with its convex surface facing the object. The sixth lens group G6 consists of a cemented lens of a biconvex lens and a concave meniscus lens with its convex surface facing the image side. The seventh lens group G7 consists of a cemented lens of a convex meniscus lens with its convex surface facing the image side and a biconcave lens, and a cemented lens of a concave meniscus lens with its convex surface facing the object side, a biconvex lens and a biconcave lens. The eighth lens group G8 consists of a cemented lens of a biconvex lens and a biconcave lens, and a concave meniscus lens with its convex surface facing the image side.

[0206] When changing magnification from the wide-angle end to the telephoto end, the 8th lens group G8 is fixed relative to the image plane, the 1st lens group G1 moves toward the object, the 2nd lens group G2 moves toward the image, the 3rd lens group G3 moves toward the image, and the 4th lens group G4 to the 7th lens group G7 each move toward the object. The distance between the 1st lens group G1 and the 2nd lens group G2 increases, the distance between the 2nd lens group G2 and the 3rd lens group G3 decreases, the distance between the 3rd lens group G3 and the 4th lens group G4 decreases, the distance between the 4th lens group G4 and the 5th lens group G5 decreases, the distance between the 5th lens group G5 and the 6th lens group G6 increases, the distance between the 6th lens group G6 and the 7th lens group G7 decreases, and the distance between the 7th lens group G7 and the 8th lens group G8 increases. When focusing from an object at infinity to an object at close range, the 6th lens group G6 moves toward the object along the optical axis.

[0207] The specifications of the variable magnification imaging optical system according to Example 13 are shown below. Numerical Example 13 Unit: mm [Surface data] Face number rd nd vd ΔPgF Applicable glass material 0 (d0) 1 364.0187 3.0000 1.61340 44.27 -0.0054 S-NBM51 2 144.4477 0.1006 3 146.2030 9.0089 1.49700 81.54 0.0358 S-FPL51 4 -1847.3364 0.3000 5 153.5443 8.6410 1.43875 94.66 0.0560 S-FPL55 6 2636.2840 (d6) 7 -126.4260 1.8000 1.84666 23.78 0.0136 FDS90-SG 8 616.6143 6.4528 1.67270 32.17 0.0058 E-FD5 9 -134.7347 0.3000 10 174.6621 6.3652 1.76634 35.83 -0.0046 S-NBH59 11 -245.7716 2.0500 1.59522 67.73 0.0177 S-FPM2 12 -683.3831 (d12) 13 621.2712 3.3627 1.84666 23.78 0.0136 FDS90-SG 14 -143.0480 2.5000 15 1123.6478 1.0000 1.80400 46.53 -0.0070 S-LAH65VS 16 73.5163 3.7404 17 -75.7910 1.0000 1.76385 48.49 -0.0022 S-LAH96 18 74.5979 3.9002 1.85451 25.15 0.0071 NBFD25 19 -383.8478 4.1736 20 -57.9235 1.0000 1.89190 37.13 -0.0035 S-LAH92 21 76.3910 3.2979 1.75520 27.53 0.0109 E-FD4L 22 485.1073 (d22) 23 245.1306 3.7431 1.59522 67.73 0.0177 S-FPM2 24 -105.4206 0.3000 25 82.3750 6.3133 1.43700 95.10 0.0564 FCD100 26 -49.5639 1.0000 1.77250 49.62 -0.0088 TAF1 27 -390.2942 3.0000 28 (aperture) ∞ (d28) 29 56.5846 1.0000 1.65160 58.54 -0.0041 S-LAL7Q 30 39.8104 10.1886 1.43700 95.10 0.0564 FCD100 31 -78.4544 1.5779 32 29.3661 3.0754 1.69930 51.11 -0.0012 S-LAL20 33 40.3977 0.8999 1.90110 27.06 0.0076 NBFD27 34 26.5305 (d34) 35 53.0578 5.1360 1.53172 48.84 0.0025 S-TIL6 36 -47.0988 0.9000 1.76385 48.49 -0.0022 S-LAH96 37 -148.7186 (d37) 38 -221.8563 3.7106 1.64769 33.79 0.0063 S-TIM22 39 -35.3782 1.0000 1.76385 48.49 -0.0022 S-LAH96 40 47.6910 10.6593 41 38.3514 0.9999 1.90525 35.04 -0.0005 S-LAH93 42 25.6168 11.0194 1.55298 55.07 -0.0046 J-KZFH4 43 -24.4628 1.0000 1.43700 95.10 0.0564 FCD100 44 47.3726 (d44) 45 96.4298 6.4202 1.76634 35.83 -0.0046 S-NBH59 46 -36.2920 0.9999 1.53775 74.70 0.0254 S-FPM3 47 177.4445 5.2193 48 -41.8822 0.9000 1.95375 32.32 0.0003 S-LAH98 49 -106.1830 36.7976 50 ∞ 2.5000 1.51680 64.20 0.0014 BSC7 51 ∞ (BF) [Various Data] Zoom ratio 3.74 Wide-angle (INF) Intermediate (INF) Telephoto (INF) Focal length 154.50 300.00 577.80 F-numbers: 4.70, 5.22, 6.47 Full angle of view 2ω 15.66 8.06 4.18 Image height Y 21.63 21.63 21.63 Lens length: 295.00 355.13 397.86 [Variable interval data] Wide-angle (INF) Wide-angle (close-up) Intermediate (INF) (d0) ∞ 2470.0000 ∞ (d6) 6.0877 6.0877 97.8049 (d12) 35.0780 35.0780 15.3742 (d22) 31.2854 31.2854 12.1804 (d28) 19.9943 19.9943 15.4517 (d34) 7.9084 5.4623 11.2681 (d37) 10.1812 12.6273 12.8265 (d44) 3.1115 3.1115 8.8668 (BF) 1.0000 1.0000 1.0000 Intermediate (close range) Telephoto (INF) Telephoto (close range) (d0) 2470.0000 ∞ 2470.0000 (d6) 97.8049 148.7388 148.7388 (d12) 15.3742 2.0000 2.0000 (d22) 12.1804 2.0000 2.0000 (d28) 15.4517 2.8817 2.8817 (d34) 3.8822 28.3467 8.5299 (d37) 20.2124 2.0000 21.8168 (d44) 8.8668 30.5356 30.5356 (BF) 1.0000 1.0000 1.0000 [Lens group data] Group starting plane focal length G1 1 264.4733 G2 7 231.6391 G3 13 -34.4325 G4 23 113.3095 G5 29 110.8375 G6 35 97.9598 G7 38 -62.6019 G8 45 -783.9058

[0208] The following is a list of corresponding values ​​for the conditional expressions in each of the above embodiments. 。 Conditional Expression / Examples EX1 EX2 EX3 EX4 EX5 (1) f1 / fT 0.4 0.4 0.5 0.5 0.4 (2) f2 / fT 0.23 0.33 0.75 0.44 0.25 (3) g2AXhW / g2AXhT 0.9 0.8 0.7 0.7 0.8 (4)(g2OAhw / Wih)-(g2OAhT / Tih) -0.6 -0.7 -0.8 -0.7 -0.9 (5) |g2OAhW / g2AXhT| 1.1 1.1 1.2 1.2 1.4 (6) DG1G2W / DG1G2T 0.108 0.041 0.075 0.096 0.122 (7) DG2G3W / DG2G3T 9.23 2.95 2.82 1.97 9.02 (8) DG1G2W / DG2G3W 0.76 0.18 0.27 0.46 0.92 (9) DG1G2T / DG2G3T 64.7 13.1 10.2 9.3 68.3 (10) ΔPgFLg2 0.0281 0.0327 0.0110 0.0281 0.0351 (11) f1 / fW 1.5 1.6 1.9 2.0 1.7 (12) f2 / fW 0.9 1.3 3.1 1.8 0.9 (13) DG2Sw / DG2St 1.6 1.5 1.7 1.6 1.8 (14) |fGM2 / fT| 0.19 0.22 0.12 0.12 0.18 (15) ΔPgFnLr 0.019 0.033 0.025 0.037 0.033 (16) νdnLr×ΔPgFnLr 1.32 0.89 1.90 3.04 0.89 (17) ΔPgFpLr -0.0054 -0.0054 -0.0081 -0.0094 -0.0030 (18) ΔPgFprAVE -0.0054 -0.0018 -0.0043 -0.0050 -0.0056 Horizontal / Dischargeable EX6 EX7 EX8 EX9 (1) f1 / fT 0.5 0.4 0.4 0.5 (2) f2 / fT 0.78 0.43 0.33 0.96 (3) g2AXhW / g2AXhT 0.7 1.0 0.9 0.5 (4)(g2OAhw / With)-(g2OAhT / Do) -0.8 -1.4 -1.1 -1.0 (5) |g2OAhW / g2AXhT| 1.2 1.7 1.6 1.6 (6) DG1G2W / DG1G2T 0.015 0.011 0.015 0.012 (7) DG2G3W / DG2G3T 1.81 29.33 12.57 9.78 (8) DG1G2W / DG2G3W 0.04 0.03 0.07 0.09 (9) DG1G2T / DG2G3T 5.1 89.1 57.4 68.1 (10) ΔPgFLg2 0.0351 0.0281 0.0192 0.0281 (11) f1 / fW 1.9 1.5 1.7 3.2 (12) f2 / fW 3.2 1.7 1.2 6.7 (13) DG2Sw / DG2St 1.6 3.0 2.3 2.9 (14) |fGM2 / fT| 0.15 0.14 0.15 0.14 (15) ΔPgFnLr 0.056 0.027 0.027 0.019 (16) νdnLr×ΔPgFnLr 5.30 2.07 2.07 1.32 (17) ΔPgFpLr -0.0081 -0.0054 -0.0054 -0.0081 (18) ΔPgFprAVE -0.0040 -0.0054 -0.0054 -0.0093 EX10 EX11 EX12 EX13 (1) f1 / fT 0.4 0.5 0.4 0.5 (2) f2 / fT 0.45 0.31 0.42 0.40 (3) g2AXhW / g2AXhT 0.9 0.4 0.9 0.8 (4)(g2OAhw / With)-(g2OAhT / Do) -1.3 -0.9 -1.2 -1 (5) |g2OAhW / g2AXhT| 1.5 1.3 1.5 1.5 (6) DG1G2W / DG1G2T 0.011 0.013 0.020 0.041 (7) DG2G3W / DG2G3T 26.04 1.14 25.34 17.54 (8) DG1G2W / DG2G3W 0.04 0.12 0.07 0.17 (9) DG1G2T / DG2G3T 85.1 10.1 90.5 74.4 (10) ΔPgFLg2 0.0281 0.0110 0.0281 0.0177 (11) f1 / fW 1.5 3.5 1.5 1.7 (12) f2 / fW 1.7 2.2 1.6 1.5 (13) DG2Sw / DG2St 2.5 2.2 2.5 2.1 (14) |fGM2 / fT| 0.14 0.16 0.13 0.17 (15) ΔPgFnLr 0.056 0.025 0.056 0.025 (16) νdnLr × ΔPgFnLr 5.36 1.90 5.36 1.90 (17) ΔPgFpLr -0.0081 -0.0081 -0.0081 -0.0046 (18) ΔPgFprAVE -0.0068 -0.0093 -0.0081 -0.0046

[0209] <Other embodiments> The technology disclosed in this embodiment is not limited to the above-described embodiments and examples, and various modifications are possible. The shapes and numerical values ​​of each part shown in the above numerical examples are all examples for implementing this technology, and the technical scope of this technology should not be interpreted as being limited by them.

[0210] Furthermore, although the above embodiments and examples describe a configuration consisting of eight or nine lens groups, a configuration with lenses that substantially have no refractive power is also possible.

[0211] This technology can also take the following configuration. [1] Starting from the object side, the lens consists of a first lens group G1 with positive refractive power, a second lens group G2 with positive refractive power, a third lens group G3 with negative refractive power, a first intermediate group GM1 consisting of one or more lens groups including an aperture diaphragm S, a second intermediate group GM2, and a subsequent group GR consisting of one or more lens groups. The aforementioned second lens group G2 includes one or more concave lenses. The spacing between adjacent lens groups changes during magnification or focusing, and when magnification changes from the wide-angle end to the telephoto end, the first lens group G1 moves toward the object. The aforementionedA variable magnification imaging optical system characterized in that the second lens group G2 is fixed with respect to the image plane, the distance between the first lens group G1 and the second lens group G2 increases, the distance between the second lens group G2 and the third lens group G3 decreases, and at least the second intermediate group GM2 moves along the optical axis when focusing from an object at infinity to an object at a close distance. [2] A variable-magnification imaging optical system comprising, in order from the object side, a first lens group G1 having positive refractive power, a second lens group G2 having positive refractive power, a third lens group G3 having negative refractive power, a first intermediate group GM1 consisting of one or more lens groups including an aperture diaphragm S, a second intermediate group GM2, and a subsequent group GR consisting of one or more lens groups, wherein the spacing between adjacent lens groups changes during magnification or focusing, and when magnifying from the wide-angle end to the telephoto end, the first lens group G1 moves toward the object side, the second lens group G2 moves toward the image side, the spacing between the first lens group G1 and the second lens group G2 increases, and the third lens group G3 moves such that the spacing between it and the second lens group G2 decreases, and when focusing from an object at infinity to an object at close range, at least the second intermediate group GM2 moves along the optical axis. [3] A variable-magnification imaging optical system according to [1] or [2], characterized in that it satisfies the following condition (1). (1) 0.2 <f1 / fT<1.0 f1: Focal length of the first lens group G1 fT: Total focal length of the system at the infinity telephoto end [4] A variable-magnification imaging optical system according to any one of [1] to [3], characterized in that it satisfies the following condition (2). (2) 0.10 <f2 / fT<1.40 f2: Focal length of the second lens group G2. fT: Total focal length of the system at the infinity telephoto end [5] The variable magnification imaging optical system according to any one of [1] to [4], characterized in that the second lens group G2 satisfies the following condition (3). (3) 0.2 <g2AXhW / g2AXhT<1.5 g2AXhW: Height of the axial marginal rays on the leading plane of the second lens group G2 at the wide-angle end at infinity with the aperture wide open. g2AXhT: Height of the axial marginal rays on the leading surface of the second lens group G2 at the infinity telephoto end with the aperture wide open. [6] The variable magnification imaging optical system according to any one of [1] to [5], characterized in that the second lens group G2 satisfies the following conditions (4) and (5). (4)-1.8<(g2OAhW / Wih)―(g2OAhT / Tih)<-0.3 (5) 0.6 < |g2OAhW / g2AXhT| < 2.5 With: Maximum image height of the off-axis principal ray at the widest angle of view at infinity. Tih: Maximum image height of the off-axis principal ray at the maximum field of view at the telephoto end of infinity. g2OAhW: Height of the off-axis principal ray at the front surface of the second lens group G2 at the wide-angle end of infinity. g2OAhT: Height of the off-axis principal ray at the front surface of the second lens group G2 at the infinity telephoto end, where the angle of view is at its maximum. g2AXhT: Height of the axial marginal rays on the leading surface of the second lens group G2 at the infinity telephoto end with the aperture wide open. [7] The following condition (6) is satisfied, as described in any of [1] to [6] Variable magnification imaging optical system. (6) 0.005 <DG1G2W / DG1G2T<0.400 DG1G2W: Distance on the optical axis between the first lens group G1 and the second lens group G2 at the wide-angle end of infinity. DG1G2T: Distance on the optical axis between the first lens group G1 and the second lens group G2 at the infinity telephoto end. [8] A variable-magnification imaging optical system according to any one of [1] to [7], characterized in that it satisfies the following condition (7). (7) 1.0 <DG2G3W / DG2G3T<80.0 DG2G3W: Distance on the optical axis between the second lens group G2 and the third lens group G3 at the wide-angle end of infinity. DG2G3T: Distance on the optical axis between the second lens group G2 and the third lens group G3 at the infinity telephoto end. [9] A variable-magnification imaging optical system according to any one of [1] to [8], characterized in that it satisfies the following condition (8). (8) 0.01 <DG1G2W / DG2G3W<2.00 DG1G2W: Distance on the optical axis between the first lens group G1 and the second lens group G2 at the wide-angle end of infinity. DG2G3W: Distance on the optical axis between the second lens group G2 and the third lens group G3 at the wide-angle end of infinity.

[10] A variable-magnification imaging optical system according to any one of [1] to [9], characterized in that it satisfies the following condition (9). (9) 2.0 <DG1G2T / DG2G3T<200.0 DG1G2T: Distance on the optical axis between the first lens group G1 and the second lens group G2 at the infinity telephoto end. DG2G3T: Distance on the optical axis between the second lens group G2 and the third lens group G3 at the infinity telephoto end.

[11] The second lens group G2 is characterized by including one or more concave lenses. 2 A variable magnification imaging optical system as described in any of

[10] .

[12] The variable magnification imaging optical system according to any one of [1] to

[11] , characterized in that the second lens group G2 includes at least one concave lens that satisfies the following condition (10). (10)ΔPgFLg2>0.0090 ΔPgFLg2: The anomalous dispersion of the concave lens with the greatest anomalous dispersion among the concave lenses included in the second lens group G2.

[13] A variable-magnification imaging optical system according to any one of [1] to

[12] , characterized in that it satisfies the following condition (11). (11) 1.0 <f1 / fW<5.0 f1: Focal length of the first lens group G1 fW: Total focal length of the system at the wide-angle end at infinity

[14] A variable-magnification imaging optical system according to any one of [1] to

[13] , characterized in that it satisfies the following condition (12). (12) 0.5 <f2 / fW<8.5 f2: Focal length of the second lens group G2. fW: Total focal length of the system at the wide-angle end at infinity

[15] The variable magnification imaging optical system according to claim 1 or 2, characterized in that it satisfies the following condition (13). (13) 1.2 <DG2Sw / DG2St<5.0 DG2Sw: Distance from the top of the object side of the lens closest to the object in the second lens group G2 at the wide-angle end to the aperture diaphragm S. DG2St: Distance from the top of the object side of the lens closest to the object in the second lens group G2 at the telephoto end to the aperture diaphragm S.

[16] The variable magnification imaging optical system according to any one of [1] to

[15] , wherein the second intermediate group GM2 is the group that moves in the optical axis direction when focusing from an object at infinity to an object at close range, and the amount of movement from infinity to the nearest end at the telephoto end is the largest, and the following condition equation (14) is satisfied. (14) 0.05 < |fGM2 / fT| < 0.40 fGM2: Focal length of the second intermediate group fT: Total focal length of the system at the infinity telephoto end

[17] A variable magnification imaging optical system according to any one of [1] to

[16] , characterized in that the lens group closest to the image sensor among the lens groups constituting the subsequent group GR includes at least one concave lens that satisfies the following condition (15). (15)ΔPgFnLr>0.009 ΔPgFnLr: Anomalous dispersion of the concave lens in the image-side lens group among the lens groups constituting the subsequent group GR.

[18] A variable magnification imaging optical system according to any one of [1] to

[17] , characterized in that the lens group closest to the image sensor among the lens groups constituting the subsequent group GR includes at least one concave lens that satisfies the following condition (16). (16) 0.80 < νdnLr × ΔPgFnLr νdnLr: Abbe number of the concave lens in the image-side lens group among the lens groups constituting the subsequent group GR. ΔPgFnLr: Anomalous dispersion of the concave lens in the image-side lens group among the lens groups constituting the subsequent group GR.

[19] A variable magnification imaging optical system according to any one of [1] to

[18] , characterized in that the image-side lens group among the lens groups constituting the subsequent group GR includes at least one convex lens that satisfies the following condition (17). (17)ΔPgFpLr<-0.0010 ΔPgFpLr: Anomalous dispersion of the convex lens in the image-side lens group among the lens groups constituting the subsequent group GR.

[20] A variable magnification imaging optical system according to any one of [1] to

[19] , characterized in that the two convex lenses closest to the image side satisfy the following condition (18). (18)ΔPgFprAVE<-0.0010 ΔPgFprAVE: Average value of the anomalous dispersion of the two convex lenses closest to the image. [twenty one] A variable magnification imaging optical system according to any one of the following [1] to

[20] , characterized in that the lens group positioned closest to the image plane among the subsequent group GR is fixed with respect to the image plane when the magnification changes from the wide-angle end to the telephoto end.

[0212] Those skilled in the art will be able to conceive of various modifications, combinations, subcombinations, and changes depending on design requirements and other factors, and it goes without saying that these fall within the scope of the attached claims and their equivalents. [Explanation of symbols]

[0213] G1 First Lens Group G2 Second Lens Group G3 3rd lens group G4 4th lens group G5 5th lens group G6 6th lens group G7 7th lens group G8 8th lens group G9 9th lens group GM1 1st intermediate group GM2 2nd intermediate group GR follow-up group S Aperture diaphragm F filter I image plane

Claims

1. A variable-magnification imaging optical system comprising, in order from the object side, a first lens group G1 having positive refractive power, a second lens group G2 having positive refractive power, a third lens group G3 having negative refractive power, a first intermediate group GM1 consisting of one or more lens groups including an aperture diaphragm S, a second intermediate group GM2, and a subsequent group GR consisting of one or more lens groups, wherein the second lens group G2 includes one or more concave lenses, the spacing between adjacent lens groups changes during magnification or focusing, when magnifying from the wide-angle end to the telephoto end, the first lens group G1 moves toward the object, the second lens group G2 is fixed relative to the image plane, the spacing between the first lens group G1 and the second lens group G2 increases, and the spacing between the second lens group G2 and the third lens group G3 decreases, and when focusing from an object at infinity to an object at close range, at least the second intermediate group GM2 moves along the optical axis.

2. Starting from the object side, the lens consists of a first lens group G1 with positive refractive power, a second lens group G2 with positive refractive power, a third lens group G3 with negative refractive power, a first intermediate group GM1 consisting of one or more lens groups including an aperture diaphragm S, a second intermediate group GM2, and one or more lens groups. A variable-magnification imaging optical system comprising a successor group GR, wherein the spacing between adjacent lens groups changes during magnification or focusing, and when magnifying from the wide-angle end to the telephoto end, the first lens group G1 moves toward the object, the second lens group G2 moves toward the image, the spacing between the first lens group G1 and the second lens group G2 increases, and the third lens group G3 moves such that the spacing between it and the second lens group G2 decreases, and when focusing from an object at infinity to an object at close range, at least the second intermediate group GM2 moves along the optical axis.

3. The variable magnification imaging optical system according to claim 1 or 2, characterized in that it satisfies the following condition (1). (1) 0.2<f1 / fT<1.0 f1: Focal length of the first lens group G1 fT: Total focal length of the system at the far end of the telescope at infinity.

4. The variable magnification imaging optical system according to claim 1 or 2, characterized in that it satisfies the following condition (2). (2) 0.10<f2 / fT<1.40 f2: Focal length of the second lens group G2 fT: Total focal length of the system at the far end of the telescope at infinity.

5. The variable magnification imaging optical system according to claim 1 or 2, characterized in that the second lens group G2 satisfies the following condition (3). (3) 0.2<g2AXhW / g2AXhT<1.5 g2AXhW: Height of the axial marginal ray on the leading surface of the second lens group G2 at the wide-angle end at infinity with the aperture wide open. g2AXhT: Height of the axial marginal ray on the leading surface of the second lens group G2 at the telephoto end of infinity with the aperture wide open.

6. The variable magnification imaging optical system according to claim 1 or 2, characterized in that the second lens group G2 satisfies the following conditions (4) and (5). (4) -1.8<(g2OAhW / Wih)-(g2OAhT / Tih)<-0.3 (5) 0.6<|g2OAhW / g2AXhT|<2.5 With: Maximum image height of the off-axis principal rays at the widest angle of view at infinity. Tih: Maximum image height of the off-axis principal rays at the maximum field of view at the telephoto end of infinity. g2OAhW: Height of the off-axis principal ray at the maximum angle of view on the leading surface of the second lens group G2 at the wide-angle end of infinity. g2OAhT: Height of the off-axis principal ray at the maximum angle of view on the leading surface of the second lens group G2 at the infinity telephoto end. g2AXhT: Height of the axial marginal ray on the leading surface of the second lens group G2 at the telephoto end of infinity with the aperture wide open.

7. The variable magnification imaging optical system according to claim 1 or 2, characterized in that it satisfies the following condition (6). (6) 0.005<DG1G2W / DG1G2T<0.400 DG1G2W: Distance on the optical axis between the first lens group G1 and the second lens group G2 at the wide-angle end at infinity. DG1G2T: Distance on the optical axis between the first lens group G1 and the second lens group G2 at the infinity telephoto end.

8. The variable magnification imaging optical system according to claim 1 or 2, characterized in that it satisfies the following condition (7). (7) 1.0<DG2G3W / DG2G3T<80.0 DG2G3W: Distance on the optical axis between the second lens group G2 and the third lens group G3 at the wide-angle end at infinity. DG2G3T: Distance on the optical axis between the second lens group G2 and the third lens group G3 at the infinity telephoto end.

9. The variable magnification imaging optical system according to claim 1 or 2, characterized in that it satisfies the following condition (8). (8) 0.01<DG1G2W / DG2G3W<2.00 DG1G2W: Distance on the optical axis between the first lens group G1 and the second lens group G2 at the wide-angle end at infinity. DG2G3W: Distance on the optical axis between the second lens group G2 and the third lens group G3 at the wide-angle end at infinity.

10. The variable magnification imaging optical system according to claim 1 or 2, characterized in that it satisfies the following condition (9). (9) 2.0<DG1G2T / DG2G3T<200.0 DG1G2T: Distance on the optical axis between the first lens group G1 and the second lens group G2 at the infinity telephoto end. DG2G3T: Distance on the optical axis between the second lens group G2 and the third lens group G3 at the infinity telephoto end.

11. The variable magnification imaging optical system according to claim 2, characterized in that the second lens group G2 includes one or more concave lenses.

12. The variable magnification imaging optical system according to claim 1 or 2, characterized in that the second lens group G2 includes at least one concave lens that satisfies the following condition (10). (10)ΔPgFLg2>0.0090 ΔPgFLg2: The anomalous dispersion of the concave lens with the greatest anomalous dispersion among the concave lenses included in the second lens group G2.

13. The variable magnification imaging optical system according to claim 1 or 2, characterized in that it satisfies the following condition (11). (11) 1.0<f1 / fW<5.0 f1: Focal length of the first lens group G1 fW: Total focal length of the system at the wide-angle end at infinity

14. The variable magnification imaging optical system according to claim 1 or 2, characterized in that it satisfies the following conditional formula (12). (12) 0.5<f2 / fW<8.5 f2: Focal length of the second lens group G2 fW: Total focal length of the system at the wide-angle end at infinity

15. The variable magnification imaging optical system according to claim 1 or 2, characterized in that it satisfies the following condition (13). (13) 1.2<DG2Sw / DG2St<5.0 DG2Sw: The distance from the top of the object side of the lens closest to the object in the second lens group G2 at the wide-angle end to the aperture diaphragm S. DG2St: The distance from the top of the object side of the lens closest to the object in the second lens group G2 at the telephoto end to the aperture diaphragm S.

16. The variable magnification imaging optical system according to claim 1 or 2, characterized in that the second intermediate group GM2 is the group that moves in the optical axis direction when focusing from an object at infinity to an object at close range, and the amount of movement from infinity to the nearest end at the telephoto end is the largest, and satisfies the following condition (14). (14) 0.05<|fGM2 / fT|<0.40 fGM2: Focal length of the second intermediate group fT: Total focal length of the system at the far end of the telescope at infinity.

17. The variable magnification imaging optical system according to claim 1 or 2, characterized in that the lens group closest to the image sensor among the lens groups constituting the subsequent group GR includes at least one concave lens that satisfies the following condition (15). (15)ΔPgFnLr>0.009 ΔPgFnLr: Anomalous dispersion of the concave lens in the image-side lens group among the lens groups constituting the subsequent group GR.

18. The variable magnification imaging optical system according to claim 1 or 2, characterized in that the lens group closest to the image sensor among the lens groups constituting the subsequent group GR includes at least one concave lens that satisfies the following condition (16). (16) 0.80 < νdnLr × ΔPgFnLr νdnLr: Abbe number of the concave lens in the lens group closest to the image sensor among the lens groups constituting the subsequent group GR. ΔPgFnLr: Anomalous dispersion of the concave lens in the image-side lens group among the lens groups constituting the subsequent group GR.

19. The variable magnification imaging optical system according to claim 1 or 2, characterized in that the lens group closest to the image sensor among the lens groups constituting the subsequent group GR includes at least one convex lens that satisfies the following condition (17). (17) ΔPgFpLr<-0.0010 ΔPgFpLr: Anomalous dispersion of the convex lens in the image-side lens group among the lens groups constituting the subsequent group GR.

20. The variable magnification imaging optical system according to claim 1 or 2, characterized in that the two convex lenses counting from the image side satisfy the following condition (18). (18)ΔPgFprAVE<-0.0010 ΔPgFprAVE: Average value of the anomalous dispersion of the two convex lenses closest to the image.

21. The variable magnification imaging optical system according to claim 1 or 2, characterized in that the lens group positioned closest to the image plane among the subsequent group GR is fixed with respect to the image plane when the magnification changes from the wide-angle end to the telephoto end.

Images