Variable magnification imaging optical system

Abstract

To provide a variable magnification image formation optical system that has a narrow half angle of view equal to or less than approximately 5° at a telephoto end, and a large magnification ratio of approximately 10 times, has a high optical performance in a zoom entire area, and an anti-tremor function, and suppresses a weight of a focus zoom lens group.SOLUTION: A variable magnification image formation optical system comprises, in order from an object side to an image side,: a first lens group that has a positive refractive power; a second lens group that has a negative refractive power; a third lens group that has the negative refractive power; a fourth lens group that has the positive refractive power; and a subsequent lens group that consists of a plurality of lens groups. Upon varying a magnification from a wide-angle end to a telephoto end, intervals between adjacent lens groups vary, the first lens group moves to the object side, and the second lens group moves to the image side. The third lens group has an anti-tremor lens group with a negative refractive power, in which the anti-tremor lens group is displaced in an almost vertical direction relative to an optical axis, and serves to perform an anti-tremor by moving an image to the vertical direction relative to the optical axis. The subsequent lens group has a focusing lens group that moves upon focusing from an object at infinity to an object at a close distance, and the focusing lens group consists of two pieces of lenses or less.SELECTED DRAWING: Figure 1

Description

【Technical Field】 【0001】 The present invention relates to a zoom imaging optical system having an anti-vibration function used in imaging devices such as digital cameras and video cameras. 【Background Art】 【0002】 Conventionally, zoom imaging optical systems with a half angle of view at the telephoto end of 5° or less have been disclosed in Patent Documents 1 and 2. 【Prior Art Documents】 【Patent Documents】 【0003】 【Patent Document 1】 Japanese Unexamined Patent Application Publication No. 2020-20948 【Patent Document 2】 Japanese Unexamined Patent Application Publication No. 2019-20450 【Summary of the Invention】 【Problems to be Solved by the Invention】 【0004】 In recent years, in a zoom imaging optical system used in an imaging device such as a digital still camera, it is required to have high optical performance throughout the entire zoom range. Also, in order to photograph various objects without changing lenses, it is required to achieve a large zoom ratio. 【0005】 In recent years, video recording using digital still cameras has become commonplace. In video recording, to maintain focus on the subject, a common method is to constantly detect changes in contrast by continuously causing the focus lens group to vibrate slightly (wobble) in the optical axis direction, thereby determining the direction of movement of the focus lens group. When driving the focus lens group by wobbling, if the focus lens group is heavy, the actuator for driving the focus lens group becomes large, making it difficult to miniaturize and lighten the shooting lens. Also, if one tries to force a heavy focus lens group to wobble without increasing the size of the actuator, the driving noise generated by the actuator becomes loud, which is problematic because it is recorded as noise in the video recording. Therefore, variable magnification imaging optical systems suitable for video recording require lightweight focus lens groups. 【0006】 Furthermore, in variable-magnification imaging optical systems, especially those with a narrow field of view at the telephoto end, image blur due to vibrations such as camera shake is likely to occur. Therefore, it is necessary to have an image stabilization function that corrects image blur by displacing a portion of the optical system's lens group (image-stabilizing lens group) in a direction approximately perpendicular to the optical axis. In addition, when an image stabilization function is present in a variable-magnification imaging optical system, the image-stabilizing lens group is required to be small in diameter and light in weight in order to avoid increasing the size of the actuator that drives the image-stabilizing lens group. Moreover, in order to obtain sufficient image stabilization, the absolute value of the image stabilization coefficient of the image-stabilizing lens group (the ratio of the amount of image movement to the amount of movement of the image-stabilizing lens group in the direction perpendicular to the optical axis) is required to be sufficiently large. 【0007】 The optical system disclosed in Patent Document 1 has a narrow half-angle of view at the telephoto end, a large magnification ratio of 9x or more, and image stabilization, but it has the problem of insufficient weight reduction because the focusing lens group consists of 3 or 4 lenses. In addition, at the telephoto end, the distance from the exit pupil position to the image plane is large, and when applied to a mirrorless camera system with a short flange back, peripheral light beam is easily vignetted by mechanical parts around the connection point with the camera. 【0008】 The optical system disclosed in Patent Document 2 has a narrow half-angle of view at the telephoto end and achieves weight reduction by consisting of two lenses in the focusing lens group, but the magnification ratio is small, less than 4x. In addition, although it has an image stabilization function, the absolute value of the vibration stabilization coefficient is small, which presents the problem that the amount of movement required to obtain a sufficient vibration stabilization effect is large. 【0009】 This invention has been made in view of the above circumstances, and provides a variable magnification imaging optical system in which the half-angle of view at the telephoto end is narrow, about 5° or less, the magnification ratio is large, it has high optical performance throughout the entire zoom range, it has an image stabilization function, and the weight of the focusing lens group is suppressed. [Means for solving the problem] 【0010】 The lens system consists of, in order from the object side to the image side, a first lens group with positive refractive power, a second lens group with negative refractive power, a third lens group with negative refractive power, a fourth lens group with positive refractive power, and a subsequent lens group consisting of multiple lens groups. When zooming from the wide-angle end to the telephoto end, the spacing between adjacent lens groups changes, the first lens group moves toward the object side, the second lens group moves toward the image side, the third lens group has a negative refractive power vibration-damping lens group, and vibration damping is performed by displacing the vibration-damping lens group in a direction approximately perpendicular to the optical axis and moving the image in a direction perpendicular to the optical axis. The subsequent lens group has a focusing lens group that moves when focusing from an object at infinity to an object at a close distance, and has at least three lens groups whose spacing between them changes when zooming from the wide-angle end to the telephoto end. The image-side lens group has negative refractive power closest to the image, and this image-side lens group is fixed to the image plane when focusing from an object at infinity to an object at a close distance. The aforementioned focusing lens group is characterized by comprising two or fewer lenses, thereby enabling variable magnification imaging. [Effects of the Invention] 【0011】 According to the present invention, it is possible to provide a variable-magnification imaging optical system that has a narrow half-angle of view of about 5° or less at the telephoto end, a large magnification ratio of about 10x, high optical performance throughout the entire zoom range, image stabilization function, and reduced weight of the focusing lens group. [Brief explanation of the drawing] 【0012】 [Figure 1] This is a lens configuration diagram according to Embodiment 1 of the variable magnification imaging optical system of the present invention. [Figure 2] This is a longitudinal aberration diagram of the variable magnification imaging optical system of Example 1 at the wide-angle end when focused at infinity. [Figure 3] This is a longitudinal aberration diagram of the variable magnification imaging optical system of Example 1 at infinity focus for the intermediate focal length. [Figure 4] This is a longitudinal aberration diagram of the variable magnification imaging optical system of Example 1 at the telephoto end when it is focused at infinity. [Figure 5] This is a diagram of the transverse aberration of the variable magnification imaging optical system of Example 1 at the wide-angle end when focused at infinity. [Figure 6] This is a diagram of the transverse aberration of the variable magnification imaging optical system of Example 1 when the intermediate focal length is focused at infinity. [Figure 7] This is a diagram of the transverse aberration at the telephoto end of the variable magnification imaging optical system of Example 1 when it is focused at infinity. [Figure 8] This is a diagram of the lateral aberration during vibration isolation for a shake angle of 0.4° at the wide-angle end when the variable magnification imaging optical system of Example 1 is focused at infinity. [Figure 9] This is a diagram of the lateral aberration during vibration isolation for the variable magnification imaging optical system of Example 1, with respect to a shake angle of 0.4° when the intermediate focal length is focused at infinity. [Figure 10] This is a diagram of the lateral aberration during vibration isolation for a shake angle of 0.4° at the telephoto end when the variable magnification imaging optical system of Example 1 is focused at infinity. [Figure 11] This is a lens configuration diagram according to Embodiment 2 of the variable magnification imaging optical system of the present invention. [Figure 12] This is a longitudinal aberration diagram of the variable magnification imaging optical system of Example 2 at the wide-angle end when focused at infinity. [Figure 13] This is a longitudinal aberration diagram of the variable magnification imaging optical system of Example 2 when the intermediate focal length is focused at infinity. [Figure 14] This is a longitudinal aberration diagram of the variable magnification imaging optical system of Example 2 at the telephoto end when it is focused at infinity. [Figure 15] This is a diagram of the lateral aberration of the variable magnification imaging optical system of Example 2 at the wide-angle end when focused at infinity. [Figure 16]It is a lateral aberration diagram when focusing at infinity with the intermediate focal length of the zoom imaging optical system of Example 2. [Figure 17] It is a lateral aberration diagram when focusing at infinity at the telephoto end of the zoom imaging optical system of Example 2. [Figure 18] It is a lateral aberration diagram during anti - shake for a shake angle of 0.4° when focusing at infinity at the wide - angle end of the zoom imaging optical system of Example 2. [Figure 19] It is a lateral aberration diagram during anti - shake for a shake angle of 0.4° when focusing at infinity with the intermediate focal length of the zoom imaging optical system of Example 2. [Figure 20] It is a lateral aberration diagram during anti - shake for a shake angle of 0.4° when focusing at infinity at the telephoto end of the zoom imaging optical system of Example 2. [Figure 21] It is a lens configuration diagram according to Example 3 of the zoom imaging optical system of the present invention. [Figure 22] It is a longitudinal aberration diagram when focusing at infinity at the wide - angle end of the zoom imaging optical system of Example 3. [Figure 23] It is a longitudinal aberration diagram when focusing at infinity with the intermediate focal length of the zoom imaging optical system of Example 3. [Figure 24] It is a longitudinal aberration diagram when focusing at infinity at the telephoto end of the zoom imaging optical system of Example 3. [Figure 25] It is a lateral aberration diagram when focusing at infinity at the wide - angle end of the zoom imaging optical system of Example 3. [Figure 26] It is a lateral aberration diagram when focusing at infinity with the intermediate focal length of the zoom imaging optical system of Example 3. [Figure 27] It is a lateral aberration diagram when focusing at infinity at the telephoto end of the zoom imaging optical system of Example 3. [Figure 28] It is a lateral aberration diagram during anti - shake for a shake angle of 0.4° when focusing at infinity at the wide - angle end of the zoom imaging optical system of Example 3. [Figure 29] It is a lateral aberration diagram during anti - shake for a shake angle of 0.4° when focusing at infinity with the intermediate focal length of the zoom imaging optical system of Example 3. [Figure 30] It is a lateral aberration diagram during anti - shake for a shake angle of 0.4° when focusing at infinity at the telephoto end of the zoom imaging optical system of Example 3. [Figure 31] This is a lens configuration diagram according to Embodiment 4 of the variable magnification imaging optical system of the present invention. [Figure 32] This is a longitudinal aberration diagram of the variable magnification imaging optical system of Example 4 at the wide-angle end when focused at infinity. [Figure 33] This is a longitudinal aberration diagram of the variable magnification imaging optical system of Example 4 at infinity focus for the intermediate focal length. [Figure 34] This is a longitudinal aberration diagram of the variable magnification imaging optical system of Example 4 at the telephoto end when it is focused at infinity. [Figure 35] This is a diagram of the lateral aberration of the variable magnification imaging optical system of Example 4 at the wide-angle end when focused at infinity. [Figure 36] This is a diagram of the transverse aberration of the variable magnification imaging optical system of Example 4 when the intermediate focal length is focused at infinity. [Figure 37] This is a diagram of the transverse aberration at the telephoto end of the variable magnification imaging optical system of Example 4 when it is focused at infinity. [Figure 38] This is a diagram of the lateral aberration during vibration isolation for a shake angle of 0.4° at the wide-angle end when the variable magnification imaging optical system of Example 4 is focused at infinity. [Figure 39] This is a diagram of the lateral aberration during vibration isolation for the variable magnification imaging optical system of Example 4, with respect to a shake angle of 0.4° when the intermediate focal length is focused at infinity. [Figure 40] This is a diagram of the lateral aberration during vibration isolation for a shake angle of 0.4° at the telephoto end when the variable magnification imaging optical system of Example 4 is focused at infinity. [Figure 41] This is a lens configuration diagram according to Embodiment 5 of the variable magnification imaging optical system of the present invention. [Figure 42] This is a longitudinal aberration diagram of the variable magnification imaging optical system of Example 5 when it is focused at infinity at the wide-angle end. [Figure 43] This is a longitudinal aberration diagram of the variable magnification imaging optical system of Example 5 when the intermediate focal length is focused at infinity. [Figure 44] This is a longitudinal aberration diagram of the variable magnification imaging optical system of Example 5 when the telephoto end is focused at infinity. [Figure 45] This is a diagram of the lateral aberration of the variable magnification imaging optical system of Example 5 at the wide-angle end when focused at infinity. [Figure 46]This is a diagram of the transverse aberration of the variable magnification imaging optical system of Example 5 when the intermediate focal length is focused at infinity. [Figure 47] This is a diagram of the transverse aberration at the telephoto end of the variable magnification imaging optical system of Example 5 when it is focused at infinity. [Figure 48] This is a diagram of the lateral aberration during vibration isolation for a shake angle of 0.4° at the wide-angle end when the variable magnification imaging optical system of Example 5 is focused at infinity. [Figure 49] This is a diagram of the lateral aberration during vibration isolation for the variable magnification imaging optical system of Example 5, with respect to a shake angle of 0.4° when the intermediate focal length is focused at infinity. [Figure 50] This is a diagram of the lateral aberration during vibration isolation for a shake angle of 0.4° at the telephoto end when the variable magnification imaging optical system of Example 5 is focused at infinity. [Figure 51] This is a lens configuration diagram according to Embodiment 6 of the variable magnification imaging optical system of the present invention. [Figure 52] This is a longitudinal aberration diagram of the variable magnification imaging optical system of Example 6 when it is focused at infinity at the wide-angle end. [Figure 53] This is a longitudinal aberration diagram of the variable magnification imaging optical system of Example 6 when the intermediate focal length is focused at infinity. [Figure 54] This is a longitudinal aberration diagram of the variable magnification imaging optical system of Example 6 at the telephoto end when it is focused at infinity. [Figure 55] This is a diagram of the lateral aberration of the variable magnification imaging optical system of Example 6 at the wide-angle end when it is focused at infinity. [Figure 56] This is a diagram of the transverse aberration of the variable magnification imaging optical system of Example 6 when the intermediate focal length is focused at infinity. [Figure 57] This is a diagram of the transverse aberration at the telephoto end of the variable magnification imaging optical system of Example 6 when it is focused at infinity. [Figure 58] This is a diagram of the lateral aberration during vibration isolation for a shake angle of 0.4° at the wide-angle end when the variable magnification imaging optical system of Example 6 is focused at infinity. [Figure 59] This is a diagram of the lateral aberration during vibration isolation for the variable magnification imaging optical system of Example 6, with respect to a shake angle of 0.4° when the intermediate focal length is focused at infinity. [Figure 60] This is a diagram of the lateral aberration during vibration isolation for a shake angle of 0.4° at the telephoto end when the variable magnification imaging optical system of Example 6 is focused at infinity. [Figure 61] This is a lens configuration diagram relating to Embodiment 7 of the variable magnification imaging optical system of the present invention. [Figure 62] This is a longitudinal aberration diagram of the variable magnification imaging optical system of Example 7 at the wide-angle end when focused at infinity. [Figure 63] This is a longitudinal aberration diagram of the variable magnification imaging optical system of Example 7 when the intermediate focal length is focused at infinity. [Figure 64] This is a longitudinal aberration diagram of the variable magnification imaging optical system of Example 7 at the telephoto end when it is focused at infinity. [Figure 65] This is a diagram of the lateral aberration of the variable magnification imaging optical system of Example 7 at the wide-angle end when focused at infinity. [Figure 66] This is a diagram of the transverse aberration of the variable magnification imaging optical system of Example 7 when the intermediate focal length is focused at infinity. [Figure 67] This is a diagram of the transverse aberration at the telephoto end of the variable magnification imaging optical system of Example 7 when it is focused at infinity. [Figure 68] This is a diagram of the lateral aberration during vibration isolation for a shake angle of 0.4° at the wide-angle end when the variable magnification imaging optical system of Example 7 is focused at infinity. [Figure 69] This is a diagram of the lateral aberration during vibration isolation for the variable magnification imaging optical system of Example 7, with respect to a shake angle of 0.4° when the intermediate focal length is focused at infinity. [Figure 70] This is a diagram of the lateral aberration during vibration isolation for a shake angle of 0.4° at the telephoto end when the variable magnification imaging optical system of Example 7 is focused at infinity. [Figure 71] This is a lens configuration diagram relating to Embodiment 8 of the variable magnification imaging optical system of the present invention. [Figure 72] This is a longitudinal aberration diagram of the variable magnification imaging optical system of Example 8 at the wide-angle end when focused at infinity. [Figure 73] This is a longitudinal aberration diagram of the variable magnification imaging optical system of Example 8 when the intermediate focal length is focused at infinity. [Figure 74] This is a longitudinal aberration diagram of the variable magnification imaging optical system of Example 8 at the telephoto end when it is focused at infinity. [Figure 75] This is a diagram of the lateral aberration of the variable magnification imaging optical system of Example 8 at the wide-angle end when focused at infinity. [Figure 76]This is a diagram of the transverse aberration of the variable magnification imaging optical system of Example 8 when the intermediate focal length is focused at infinity. [Figure 77] This is a diagram of the transverse aberration at the telephoto end of the variable magnification imaging optical system of Example 8 when it is focused at infinity. [Figure 78] This is a diagram of the lateral aberration during vibration isolation for a shake angle of 0.4° at the wide-angle end when the variable magnification imaging optical system of Example 8 is focused at infinity. [Figure 79] This is a diagram of the lateral aberration during vibration isolation for the variable magnification imaging optical system of Example 8, with respect to a shake angle of 0.4° when the intermediate focal length is focused at infinity. [Figure 80] This is a diagram of the lateral aberration during vibration isolation for a shake angle of 0.4° at the telephoto end when the variable magnification imaging optical system of Example 8 is focused at infinity. [Modes for carrying out the invention] 【0013】 As shown in the lens configuration diagrams of the embodiments in Figures 1, 11, 21, 31, 41, 51, 61, and 71, the variable magnification imaging optical system according to the present invention consists of, in order from the object side to the image side, a first lens group with positive refractive power, a second lens group with negative refractive power, a third lens group with negative refractive power, a fourth lens group with positive refractive power, and a subsequent lens group consisting of multiple lens groups. When magnification is changed from the wide-angle end to the telephoto end, the distance between adjacent lens groups changes, the first lens group moves toward the object side, the second lens group moves toward the image side, the third lens group has a vibration-damping lens group with negative refractive power, and vibration damping is performed by displacing the vibration-damping lens group in a direction substantially perpendicular to the optical axis, and the subsequent lens group has a focusing lens group that moves when focusing from an object at infinity to an object at close range, and the focusing lens group consists of two or fewer lenses. 【0014】 The first lens group with positive refractive power and the second lens group with negative refractive power achieve the main magnification effect by increasing the distance between them when magnifying from the wide-angle end to the telephoto end. When a large magnification ratio is desired, moving only one of the lens groups would require a large amount of movement. If the amount of movement of the first lens group is too large, a double extension mechanism would be required, increasing the radial size, and eccentricity errors in the first lens group are more likely to occur, increasing the possibility of performance degradation during manufacturing, which is undesirable. On the other hand, if the amount of movement of the second lens group is too large, the overall length of the optical system at the wide-angle end will increase in order to secure space for the movement of the second lens group, making miniaturization difficult. Therefore, in the variable magnification imaging optical system of the present invention, when magnifying from the wide-angle end to the telephoto end, the first lens group is moved towards the object side and the second lens group is moved towards the image side, thereby achieving both a large magnification ratio and size control. 【0015】 The third lens group consists of a negative refractive index vibration-damping lens group, and vibration damping is achieved by displacing the vibration-damping lens group in a direction approximately perpendicular to the optical axis. In order to secure a large correction angle and obtain sufficient vibration damping effect, the vibration-damping lens group needs to have a strong negative refractive index. If the refractive index of the entire third lens group were to be positive, the lens groups other than the vibration-damping lens group would need to have an even stronger positive refractive index, which would make performance degradation due to eccentricity during manufacturing more likely. Therefore, the third lens group as a whole is configured to have a negative refractive index. 【0016】 The fourth lens group possesses a strong positive refractive power, converging the light beam to form an image, and also plays an auxiliary role in zooming by moving towards the object when zooming from the wide-angle end to the telephoto end. 【0017】 The subsequent lens group, located on the image side of the fourth lens group, is composed of multiple lens groups. The spacing between each lens group changes when zooming from the wide-angle end to the telephoto end, contributing to image plane compensation and suppression of aberration fluctuations. The subsequent lens group also includes a focusing lens group that moves when focusing from an object at infinity to an object at a close distance. By placing the focusing lens group within the subsequent lens group into which the light beam converged by the fourth lens group enters, it is possible to reduce the outer diameter of the focusing lens group. Furthermore, by composing the focusing lens group with two or fewer lenses, it is possible to reduce the weight of the focusing lens group. 【0018】 Furthermore, in the variable-magnification imaging optical system according to the present invention, it is desirable that the second lens group has at least two negative lenses and one positive lens. In order to obtain a large magnification ratio, it is necessary to strengthen the negative refractive power of the second lens group. By distributing the refractive power among at least two negative lenses, a strong negative refractive power is obtained while suppressing various aberrations, including spherical aberration and coma aberration. In addition, the configuration with a positive lens makes it possible to reduce chromatic aberration. Furthermore, it is desirable that the following conditional equations be satisfied. (1) 4.0 < β2T / β2W < 15.0 (2) -15.0 <fT / f2<-5.0 however, β2T: Lateral magnification of the second lens group when focused at infinity at the telephoto end. β2W: Lateral magnification of the second lens group when focused at infinity at the wide-angle end. fT: Total focal length of the lens system when focused at infinity at the telephoto end. f2: Focal length of the second lens group 【0019】 Conditional equation (1) defines a preferred range for the ratio of the lateral magnification of the second lens group at the wide-angle end and the telephoto end, that is, the magnitude of the magnification effect of the second lens group. 【0020】 If the ratio of the lateral magnification of the second lens group at the wide-angle end and the telephoto end becomes small, exceeding the lower limit of condition (1), the magnification burden on the image-side lens group becomes larger than that of the third lens group in order to obtain a large magnification ratio. Since the third lens group has an image-stabilizing lens group, it is preferable for the amount of movement during magnification to be small for mechanical reasons, and the amount of movement of the image-side lens groups from the fourth lens group onwards is also limited accordingly. Therefore, in order to increase the magnification effect of the image-side lens groups from the third lens group onwards, it is necessary to increase the refractive power of each group, making it difficult to suppress various aberrations during magnification. On the other hand, if the ratio of the lateral magnification of the second lens group at the wide-angle end and the telephoto end becomes large, exceeding the upper limit of condition (1), it is undesirable because it becomes excessive for the magnification ratio of the entire lens system. 【0021】 Furthermore, regarding condition (1), it is preferable to limit its lower limit to 5.0 and its upper limit to 12.0 to make the aforementioned effect more reliable. 【0022】 Conditional equation (2) specifies a preferred range for the ratio of the focal length of the entire optical system to the focal length of the second lens group when the telephoto end is in focus at infinity. 【0023】 If the negative refractive power of the second lens group becomes stronger, exceeding the lower limit of condition (2), the ray height of the light rays incident on the vibration-damping lens group within the third lens group increases, making it difficult to miniaturize and lighten the vibration-damping lens group. On the other hand, if the negative refractive power of the second lens group becomes weaker, exceeding the upper limit of condition (2), the magnification effect caused by widening the distance between the first and second lens groups decreases, making it difficult to obtain a large magnification ratio. 【0024】 Furthermore, regarding condition (2), it is preferable to limit its lower limit to -13.0 and its upper limit to -6.5 to make the aforementioned effect more reliable. 【0025】 Furthermore, in the variable magnification imaging optical system according to the present invention, the third lens group is composed of a third a lens group with positive refractive power and a third b lens group with negative refractive power, in order from the object side to the image side. It is desirable to perform vibration isolation by displacing the third b lens group as a vibration isolation lens group in a direction substantially perpendicular to the optical axis. By arranging the third a lens group with positive refractive power, it becomes easier to cancel out the various aberrations generated by the vibration isolation lens group with strong negative refractive power and suppress various aberrations within the third lens group. In addition, by arranging the lens group with positive refractive power closer to the object than the vibration isolation lens group, the diameter of the on-axial light beam incident on the vibration isolation lens group is reduced, which also contributes to miniaturizing the vibration isolation lens group. Furthermore, it is desirable that the following conditional equations be satisfied. (3) -8.0 <fT / f3<0.0 (4) 5.0 <fT / f3a<15.0 however, fT: Total focal length of the lens system when focused at infinity at the telephoto end. f3: Focal length of the third lens group f3a: Focal length of the aforementioned 3a lens group 【0026】 Conditional equation (3) specifies a preferred range for the ratio of the focal length of the entire optical system to the focal length of the third lens group when the telephoto end is in focus at infinity. 【0027】 When the negative refractive power of the third lens group increases beyond the lower limit of condition (3), the negative refractive power of the vibration-damping lens group increases, or the positive refractive power of the thirda lens group decreases. When the negative refractive power of the vibration-damping lens group increases, the weight of the vibration-damping lens group increases, and the vibration-damping actuator becomes larger. Also, when the positive refractive power of the thirda lens group decreases, the effects of canceling out various aberrations generated in the vibration-damping lens group and suppressing the axial light beam diameter incident on the vibration-damping lens group are not obtained. On the other hand, when the third lens group becomes positively refractive, exceeding the upper limit of condition (3), the negative refractive power of the vibration-damping lens group decreases, or the positive refractive power of the thirda lens group increases. When the negative refractive power of the vibration-damping lens group decreases, it becomes difficult to sufficiently increase the absolute value of the vibration damping coefficient, and if the shift movement amount of the vibration-damping lens group is increased to obtain a sufficient correction angle, the vibration damping mechanism becomes larger in the radial direction. Furthermore, if the positive refractive power of the third a lens group becomes strong, performance degradation is more likely to occur if the third a lens group or the vibration-damping lens group becomes eccentric during manufacturing. 【0028】 Furthermore, regarding condition (3), it is preferable to limit its lower limit to -6.0 and its upper limit to -0.5 to make the aforementioned effect more reliable. 【0029】 Conditional equation (4) specifies a preferred range for the ratio of the focal length of the entire optical system to the focal length of the third lens group a when the telephoto end is in focus at infinity. 【0030】 If the positive refractive power of the third a lens group weakens beyond the lower limit of condition (4), the effect of canceling out various aberrations generated by the vibration-damping lens group and suppressing the axial light beam diameter incident on the vibration-damping lens group will weaken. On the other hand, if the positive refractive power of the third a lens group strengthens beyond the upper limit of condition (4), performance degradation is more likely to occur if the third a lens group or the vibration-damping lens group is eccentric during manufacturing. 【0031】 Furthermore, regarding conditional equation (4), it is preferable to limit its lower limit to 7.0 and its upper limit to 13.0 to make the aforementioned effect more certain. 【0032】 Furthermore, in the variable-magnification imaging optical system according to the present invention, it is desirable that the image-stabilizing lens group be fixed to the image plane when the magnification changes from the wide-angle end to the telephoto end. If the image-stabilizing lens group moves during magnification, it is necessary to move it together with the image-stabilizing mechanism, which includes an actuator for driving the image-stabilizing lens group perpendicular to the optical axis. This makes the mechanism for movement larger and more complex, making it difficult to miniaturize and lighten the photographic lens. 【0033】 Furthermore, it is desirable that the image stabilization lens group consists of two negative lenses and one positive lens. The image stabilization lens group has a strong negative refractive power, but in order to suppress chromatic aberration due to eccentricity during image stabilization, it is desirable that the color is abolished within the image stabilization lens group, and it is desirable to have at least one positive lens. Also, in order to suppress fluctuations in coma and astigmatism due to eccentricity during image stabilization, there is insufficient freedom with only one negative lens and one positive lens, so it is desirable to have at least two negative lenses. Increasing the number of lenses makes it easier to suppress aberration fluctuations during image stabilization, but in order to suppress the lens weight of the image stabilization lens group, it is desirable to consist of only two negative lenses and one positive lens. Furthermore, it is desirable that the following conditional equations be satisfied. (5) 3.5<|(1-βosT)×βRosT|<10.0 (6) -25.0 <fT / fos<-10.0 (7) νdosn-νdosp>30.0 however, βosT: Lateral magnification of the image-stabilizing lens group when focused at infinity at the telephoto end. βRosT: Lateral magnification of the lens system located on the image side of the aforementioned image-stabilizing lens group when focusing at infinity at the telephoto end. fT: Total focal length of the lens system when focused at infinity at the telephoto end. fos: Focal length of the aforementioned image-stabilizing lens group νdosn: The average value of the Abbe numbers for the d line of the two negative lenses included in the vibration-damping lens group. νdosp: Abbe number of one positive lens included in the vibration-damping lens group with respect to the d line. 【0034】 Conditional equation (5) specifies a preferred range for the absolute value of the vibration isolation coefficient of the image-isolating lens group when focusing at infinity at the telephoto end. 【0035】 If the absolute value of the vibration isolation coefficient of the image stabilization lens group decreases beyond the lower limit of condition (5), the amount of movement of the image stabilization lens group perpendicular to the optical axis increases in order to obtain the required correction angle, which increases the diameter of the lens barrel and makes it difficult to miniaturize and lighten the photographic lens. On the other hand, if the absolute value of the vibration isolation coefficient of the image stabilization lens group increases beyond the upper limit of condition (5), the negative refractive force of the image stabilization lens group becomes stronger, which increases the weight of the image stabilization lens group and makes the vibration isolation actuator larger. In addition, it becomes difficult to suppress fluctuations in coma aberration and astigmatism due to eccentricity during vibration isolation. Furthermore, even a small amount of shift results in a large amount of image displacement, making it more difficult to control the vibration isolation mechanism. 【0036】 Furthermore, regarding condition (5), it is preferable to limit its lower limit to 4.2 and its upper limit to 7.0 to make the aforementioned effect more certain. 【0037】 Conditional equation (6) specifies a preferred range for the ratio of the focal length of the entire optical system to the focal length of the image-stabilizing lens group when the telephoto end is in focus at infinity. 【0038】 If the negative refractive force of the vibration-isolating lens group becomes too strong, exceeding the lower limit of condition (6), the weight of the vibration-isolating lens group increases, leading to the need for larger vibration-isolating actuators. Furthermore, it becomes difficult to suppress fluctuations in coma and astigmatism due to eccentricity during vibration isolation. On the other hand, if the negative refractive force of the vibration-isolating lens group becomes too weak, exceeding the upper limit of condition (6), it becomes difficult to maintain an appropriate vibration isolation coefficient for the vibration-isolating lens group. 【0039】 Furthermore, regarding condition (6), it is preferable to limit its lower limit to -22.0 and its upper limit to -13.0 to make the aforementioned effect more reliable. 【0040】 Conditional equation (7) specifies a preferred range for the difference in Abbe numbers between the materials of the negative and positive lenses included in the vibration-damping lens group. The larger the difference in Abbe numbers between the materials of the positive and negative lenses in the vibration-damping lens group, the easier it is to achieve achromatic achromaticity even with weaker refractive powers for each of the positive and negative lenses, thus facilitating weight reduction of the vibration-damping lens group. 【0041】 When the difference in Abbe numbers between the positive and negative lens materials becomes small, exceeding the lower limit of condition (7), it becomes difficult to suppress the weight of the lenses while abolishing color within the image stabilization lens group. 【0042】 Furthermore, regarding condition (7), it is preferable to limit its lower limit to 35.0 to make the aforementioned effect more certain. 【0043】 Furthermore, in the variable magnification imaging optical system according to the present invention, it is desirable that the fourth lens group has an aperture diaphragm. Since the fourth lens group does not include an image stabilization lens group or a focusing lens group, it is easier to secure space for arranging an aperture mechanism. Also, the fourth lens group is located in a position where the ray height of the light beam center in the peripheral angle of view tends to be relatively low, making it suitable for arranging an aperture. Furthermore, it is desirable that the following conditional equations be satisfied. (8) 4.0 <fT / f4<18.0 however, fT: Total focal length of the lens system when focused at infinity at the telephoto end. f4: Focal length of the fourth lens group 【0044】 Conditional equation (8) defines a preferred range for the ratio of the focal length of the entire optical system to the focal length of the fourth lens group when the telephoto end is in focus at infinity. 【0045】 If the positive refractive power of the fourth lens group weakens beyond the lower limit of condition (8), the light beam directed toward the subsequent lens group cannot be sufficiently focused, making it difficult to reduce the outer diameter and weight of the focusing lens group. On the other hand, if the positive refractive power of the fourth lens group strengthens beyond the upper limit of condition (8), the refractive power of each lens within the fourth lens group becomes stronger, making performance degradation more likely if the lenses within the fourth lens group are eccentric due to manufacturing variations or if there are errors in the inter-plane spacing. 【0046】 Furthermore, regarding conditional equation (8), it is preferable to limit its lower limit to 6.0 and its upper limit to 14.0 to make the aforementioned effect more certain. 【0047】 Furthermore, in the variable magnification imaging optical system according to the present invention, it is desirable that the focusing lens group be composed of a single lens or a pair of cemented lenses. Composing the focusing lens group with a single lens is most advantageous for weight reduction. When composed of two lenses, using cemented lenses eliminates the need for spacers and other components, and shortens the length of the optical axis direction of the lens chamber, which is advantageous for weight reduction of the movable parts. Furthermore, it is desirable that the following conditional equations be satisfied. (9) 3.5<|(1-βfocT^2)×βRfocT^2|<10.0 however, βfocT: Lateral magnification of the focusing lens group when infinity focus is achieved at the telephoto end. βRfocT: Lateral magnification of the lens system located on the image side of the focusing lens group when infinity focus is achieved at the telephoto end. 【0048】 Condition (9) defines a preferred range for the focus sensitivity of the focusing lens group. Furthermore, in the case of a floating-type lens configuration where multiple lens groups move along different trajectories when focusing from infinity to a near-field object, it is desirable that at least one of the focusing lens groups satisfies condition (9). 【0049】 If the focus sensitivity of the focusing lens group decreases beyond the lower limit of condition (9), the amount of movement required for the focusing lens group to focus from an object at infinity to a desired close-range object increases. The overall length of the optical system increases to accommodate the movement of the focusing lens group, making it difficult to miniaturize the imaging lens. In addition, the time required for focusing by the autofocus function also increases. On the other hand, if the focus sensitivity of the focusing lens group increases beyond the upper limit of condition (9), the tolerance range for misalignment of the focusing lens group in the optical axis direction narrows, making it difficult to properly control focusing by the autofocus function. 【0050】 Furthermore, regarding conditional equation (9), it is preferable to limit its lower limit to 4.5 and its upper limit to 8.0 to make the aforementioned effect more certain. 【0051】 Furthermore, in the variable-magnification imaging optical system according to the present invention, the subsequent lens group preferably has at least three lens groups whose spacing changes when magnification is applied from the wide-angle end to the telephoto end, with an image-side lens group having negative refractive power closest to the image, and the image-side lens group is preferably fixed to the image plane when magnification is applied from the wide-angle end to the telephoto end, and when focusing from an object at infinity to an object at close range. 【0052】 Next, by having a negative refractive power image-side lens on the image-side of the subsequent lens group, it becomes possible to reduce the ray height of the peripheral light beam directed toward the image plane. This makes it possible to ensure sufficient peripheral illumination while satisfying the ray height limitations imposed by the mechanical parts around the connection point with the camera. It also makes it easier to accommodate a detachable teleconverter attached to the image-side of the imaging lens. 【0053】 Furthermore, by fixing the image-side lens group to the image plane during magnification and focusing, the mechanism around the connection point with the camera is simplified, and the outer diameter is reduced, making it easier to avoid interference with the camera body. 【0054】 Furthermore, by including a group of lenses that move on independent trajectories during magnification, in addition to the focusing lens group and the image-side lens group, within the subsequent lens group, it becomes easier to suppress fluctuations in spherical aberration and field curvature during magnification. Therefore, it is desirable for the subsequent lens group to have at least three lens groups whose spacing from each other changes when magnification is changed from the wide-angle end to the telephoto end. Furthermore, it is desirable that the following conditional equations be satisfied. (10) 2.5 <EXPT / Ymax<6.0 however, EXPT: Distance from the exit pupil position to the image plane when focusing at infinity at the telephoto end. Ymax: Maximum image height 【0055】 Conditional equation (10) defines a preferred range for the ratio of the distance from the exit pupil position to the image plane and the maximum image height when the telephoto end is in focus at infinity. 【0056】 When the distance from the exit pupil to the image plane decreases beyond the lower limit of condition (10), the negative refractive power of the image-side lens group increases. If the negative refractive power of the image-side lens group is made too strong, the refractive power arrangement becomes more telephoto-like, which is advantageous for shortening the overall length of the lens, but it becomes difficult to suppress various aberrations, including chromatic aberration. Also, if the exit pupil is too close to the image plane, the angle of incidence of peripheral light rays to the image plane becomes large, which is undesirable in terms of the sensitivity characteristics of the image sensor. On the other hand, when the distance from the exit pupil to the image plane increases beyond the upper limit of condition (10), the ray height of the peripheral light beam directed toward the image plane increases, making it difficult to secure sufficient peripheral light while satisfying the ray height limitations imposed by the mechanical parts around the connection point with the camera. 【0057】 Furthermore, regarding conditional equation (10), it is preferable to limit its lower limit to 3.5 and its upper limit to 5.0 to make the aforementioned effect more reliable. 【0058】 Furthermore, in the variable-magnification imaging optical system according to the present invention, it is desirable that the first lens group consists of one negative lens and two positive lenses. At the telephoto end of a variable-magnification imaging optical system with positive leading, the refractive power arrangement becomes telephoto-type, and the aberrations remaining in the first lens group are amplified. Therefore, it is desirable to include a negative lens to correct color chromatic aberration. Also, having two positive lenses makes it easier to suppress spherical aberration remaining in the first lens group while ensuring sufficient positive refractive power. Suppressing various aberrations becomes even easier by further increasing the number of lenses, but since the outer diameter of the first lens group is large and leads to an increase in the weight of the imaging lens, it is desirable to have a configuration consisting of only one negative lens and two positive lenses. Furthermore, it is desirable that the following conditional equations be satisfied. (11) 1.0 <fT / f1<4.0 (12) νdmax1p>85.0 (13) θgFmax1p-0.6483+0.0018×νdmax1p>0.040 (14) 0.40 <LTT / fT<0.85 however, fT: Total focal length of the lens system when focused at infinity at the telephoto end. f1: Focal length of the first lens group νdmax1p: The Abbe number for the d line of the positive lens with the largest Abbe number among the positive lenses in the first lens group. θgFmax1p: The partial dispersion ratio of the g-line and F-line of the positive lens with the largest Abbe number among the positive lenses in the first lens group. LTT: The length from the object-side lens plane to the image plane of the entire lens system when focused at infinity at the telephoto end. Furthermore, when the refractive indices for the g-line (wavelength 435.8 nm), F-line (wavelength 486.1 nm), d-line (wavelength 587.6 nm), and C-line (wavelength 656.3 nm) are denoted as ng, nF, nd, and nC, respectively, the Abbe number νd and the partial dispersion ratio θgF are expressed by the following formulas. νd=(nd-1) / (nF-nC) θgF = (ng - nF) / (nF - nC) 【0059】 Conditional equation (11) defines a preferred range for the ratio of the focal length of the entire optical system to the focal length of the first lens group when the telephoto end is in focus at infinity. 【0060】 If the positive refractive power of the first lens group weakens beyond the lower limit of condition (11), the telephoto type refractive power arrangement at the telephoto end weakens, increasing the overall length of the lens and making it difficult to miniaturize the imaging lens. On the other hand, if the positive refractive power of the first lens group strengthens beyond the upper limit of condition (11), the telephoto type refractive power arrangement at the telephoto end strengthens, which is advantageous for shortening the overall length of the lens, but makes it difficult to suppress various aberrations, including chromatic aberration. 【0061】 Furthermore, regarding conditional equation (11), it is preferable to limit its lower limit to 2.0 and its upper limit to 3.0 to make the aforementioned effect more reliable. 【0062】 Conditional equations (12) and (13) specify desirable characteristics for the material of the positive lens in the first lens group in order to effectively correct chromatic aberration, including the second-order spectrum. 【0063】 To effectively correct chromatic aberration, including secondary spectra, it is best to combine positive and negative lenses such that the difference in Abbe numbers is large and the difference in partial dispersion ratio is small. Therefore, it is desirable to use a material with low dispersion and high anomalous dispersion (a larger partial dispersion ratio compared to ordinary materials) for the positive lens in the first lens group. 【0064】 When the Abbe number of the positive lens with the largest Abbe number among the positive lenses in the first lens group decreases beyond the lower limit of condition (12), the difference in Abbe numbers between the positive and negative lenses in the first lens group decreases, making it difficult to correct chromatic aberration. 【0065】 Furthermore, regarding condition (12), it is preferable to limit its lower limit to 92.0, which will make the aforementioned effect more certain. 【0066】 Conditional equation (13) defines a preferred range for the anomalous dispersion of the positive lens with the largest Abbe number among the positive lenses in the first lens group. 【0067】 When the lower limit of condition (13) is exceeded, and the anomalous dispersion of the positive lens with the largest Abbe number among the positive lenses in the first lens group decreases, the difference in the partial dispersion ratio between the positive and negative lenses increases, making it difficult to correct chromatic aberration, especially the second-order spectrum. 【0068】 Furthermore, regarding conditional equation (13), it is preferable to limit its lower limit to 0.050, which will make the aforementioned effect more reliable. 【0069】 Conditional equation (14) defines a preferred range for the ratio of the total lens length to the focal length when the lens is in focus at infinity at the telephoto end, known as the telephoto ratio. 【0070】 When the telephoto ratio decreases beyond the lower limit of condition (14), the telephoto type refractive power arrangement becomes stronger, making it difficult to suppress various aberrations, including chromatic aberration. On the other hand, when the telephoto ratio increases beyond the upper limit of condition (14), it leads to the need for a larger imaging lens. 【0071】 Furthermore, regarding conditional equation (14), it is preferable to limit its lower limit to 0.50 and its upper limit to 0.80, which will make the aforementioned effect more reliable. 【0072】 The variable magnification imaging optical system according to the present invention is more preferably further configured as follows. 【0073】 By introducing aspherical elements into the focusing lens group, it becomes easier to suppress variations in spherical aberration, coma aberration, and field curvature during focusing. 【0074】 The fourth lens group has a three-element cemented lens consisting of a negative lens, a positive lens, and another negative lens in that order from the object side, which makes it easier to suppress performance degradation due to eccentricity within the fourth lens group. 【0075】 Next, the lens configuration of an embodiment of the variable magnification imaging optical system of the present invention will be described. In the following description, the lens configuration will be described in order from the object side to the image side. 【0076】 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 surface, d is the spacing between each surface, nd is the refractive index for the d line (wavelength 587.56 nm), and vd is the Abbe number for the d line. 【0077】 The asterisk (*) next to the lens surface number indicates that the lens surface is aspherical. BF represents the back focus. 【0078】 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). 【0079】 The [Aspherical Data] section shows the coefficient values ​​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 defined as follows, where y is the displacement from the optical axis in the direction perpendicular to the optical axis, z is the displacement (sag) in the direction of the optical axis from the intersection of the aspherical surface and the optical axis, r is the radius of curvature of the reference sphere, K is the conic coefficient, and A4, A6, and A8 are the 4th, 6th, and 8th order aspherical coefficients, respectively, and the coordinates of the aspherical surface are expressed by the following formula. TIFF0007873847000001.tif18109 【0080】 The [Various Data] section shows values ​​such as the zoom ratio and focal length at each focal length state. 【0081】 The [Variable Interval Data] section shows the variable interval and BF values ​​for each focal length state at infinity and at an object distance of 1m. 【0082】 The [Lens Group Data] shows the number of the object-side surface in each lens group and the combined focal length of the entire group. 【0083】 Furthermore, in the aberration diagrams corresponding to each embodiment, d, g, and C represent the d line, g line, and C line, respectively, and △S and △M represent the sagittal image plane and meridional image plane, respectively. 【0084】 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 equivalent optical performance can be obtained in both proportional magnification and proportional reduction in the optical system, this is not the only unit of measurement. 【0085】 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. [Examples] 【0086】 Figure 1 is a lens configuration diagram of the variable magnification imaging optical system of Embodiment 1 of the present invention. 【0087】 Starting from the object side, the lens system consists of a first lens group G1 with positive refractive power, a second lens group G2 with negative refractive power, a third lens group G3 with negative refractive power, a fourth lens group G4 with positive refractive power, and a subsequent lens group GR consisting of multiple lens groups. The subsequent lens group GR is composed of a fifth lens group G5 with positive refractive power, a sixth lens group G6 with negative refractive power, and a seventh lens group G7 with negative refractive power. 【0088】 When changing magnification 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 third lens group G3 remains fixed relative to the image plane, the fourth lens group G4 moves toward the object, the fifth lens group G5 moves toward the object, the sixth lens group G6 moves toward the object, and the seventh lens group G7 remains fixed relative to the image plane. Also, when focusing from an object at infinity to an object at close range, the fifth lens group G5 moves toward the object along the optical axis. 【0089】 The first lens group G1 consists of a cemented lens comprising a negative meniscus lens L1 and a biconvex lens L2, both with their convex surfaces facing the object, and a positive meniscus lens L3 with its convex surface facing the object. 【0090】 The second lens group G2 consists of a cemented lens comprising a positive meniscus lens L4 with its convex surface facing the object and a negative meniscus lens L5 with its convex surface facing the object, and a negative meniscus lens L6 with its convex surface facing the object. 【0091】 The third lens group G3 consists of the third lens group G3a with positive refractive power and the third lens group G3b with negative refractive power. The third lens group G3b corresponds to the vibration isolation lens group, and vibration isolation is performed by displacing the third lens group G3b in a direction approximately perpendicular to the optical axis. The third lens group G3a consists of a positive meniscus lens L7 with a convex surface facing the image side and a positive meniscus lens L8 with a convex surface facing the object side. The third lens group G3b consists of a biconcave lens L9 and a cemented lens consisting of a biconcave lens L10 and a biconvex lens L11. 【0092】 The fourth lens group G4 consists of a biconvex lens L12, a cemented lens comprising a biconvex lens L13 and a negative meniscus lens L14 with its convex surface facing the image side, a positive meniscus lens L15 with its convex surface facing the image side, and a three-element cemented lens comprising a negative meniscus lens L16 with its convex surface facing the object side, a biconvex lens L17, and a biconcave lens L18. An aperture diaphragm S is also provided between the negative meniscus lens L14 and the positive meniscus lens L15. 【0093】 The fifth lens group G5 consists of a positive meniscus lens L19 with its convex surface facing the object. 【0094】 The sixth lens group G6 consists of a biconvex lens L20, a negative meniscus lens L21 with its convex surface facing the object, a biconcave lens L22, and a biconvex lens L23. 【0095】 The seventh lens group G7 consists of a biconvex lens L24 and a biconcave lens L25. 【0096】 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 θgF Object surface ∞ (d0) 1 265.8737 3.0000 1.80610 40.73 0.5672 2 133.3597 10.2893 1.49700 81.61 0.5389 3 -1518.2062 0.1500 4 123.5711 9.3109 1.43700 95.10 0.5336 5 988.5529 (d5) 6 98.3998 4.6862 1.80809 22.76 0.6287 7 4603.1447 1.5000 1.87070 40.73 0.5682 8 71.0826 3.5704 9 666.5204 1.5000 1.90043 37.37 0.5767 10 66.2461 (d10) 11 -493.0497 3.9036 1.48749 70.44 0.5306 12 -56.9988 0.1500 13 35.3143 4.4671 1.48749 70.44 0.5306 14 106.9387 3.2912 15 -447.6909 0.9000 1.72916 54.67 0.5453 16 45.0512 5.2423 17 -39.4556 0.9000 1.59282 68.62 0.5440 18 76.1464 3.3361 1.85478 24.80 0.6122 19 -340.9035 (d19) 20 220.2046 4.0644 1.78472 25.72 0.6158 21 -94.2729 0.1500 22 52.7964 6.7452 1.51823 58.96 0.5442 23 -48.1977 0.9000 2.05090 26.94 0.6052 24 -14519.8030 5.3500 25 (aperture) ∞ 7.2878 26 -123.9647 3.5661 1.80809 22.76 0.6287 27 -51.5585 0.1500 28 53.1871 0.9000 1.85896 22.73 0.6284 29 27.2187 8.4092 1.51742 52.15 0.5590 30 -59.2354 0.9000 1.90043 37.37 0.5767 31 844.6034 (d31) 32 52.1689 3.9553 1.55032 75.50 0.5401 33 3679.0034 (d33) 34 142.9947 2.5119 1.73037 32.23 0.5899 35 -199.4928 0.1500 36 92.5531 0.9000 1.77250 49.60 0.5520 37 25.3554 20.5704 38 -40.3661 0.9000 1.55032 75.50 0.5401 39 315.2775 0.1500 40 51.9158 4.6802 1.67270 32.17 0.5963 41 -196.8493 (d41) 42 167.1323 4.0607 1.78472 25.72 0.6158 43 -69.4451 1.1493 44 -50.5099 0.9000 2.05090 26.94 0.6052 45 234.1676 31.9792 46 ∞ 2.5000 1.52301 58.59 0.5448 47 ∞ (BF) Image plane ∞ [Various Data] Wide-angle, Medium, Telephoto Focal length 62.10 189.73 578.88 F-numbers: 4.56, 5.49, 6.50 Full angle of view 2ω 38.22 12.73 4.18 Image height Y 21.63 21.63 21.63 Lens length: 293.50 x 349.72 x 393.50 [Variable interval data] Wide-angle, Medium, Telephoto d0 ∞ ∞ ∞ d5 4.7000 88.4335 139.0970 d10 40.4453 12.9325 6.0483 d19 48.4179 27.9638 2.0000 d31 24.4018 23.0748 43.9309 d33 3.0083 6.8064 3.0000 d41 2.5000 20.4830 29.3971 BF 1.0000 1.0000 1.0000 [Lens group data] Group starting plane focal length G1 1 242.38 G2 6 -63.42 G3 11 -161.60 G4 20 60.16 G5 32 96.12 G6 34 -89.32 G7 42 -114.99 G3a 11 58.35 G3b 15 -36.35 [Examples] 【0097】 Figure 11 is a lens configuration diagram of the variable magnification imaging optical system of Embodiment 2 of the present invention. 【0098】 Starting from the object side, the lens system consists of a first lens group G1 with positive refractive power, a second lens group G2 with negative refractive power, a third lens group G3 with negative refractive power, a fourth lens group G4 with positive refractive power, and a subsequent lens group GR consisting of multiple lens groups. The subsequent lens group GR is composed of a fifth lens group G5 with positive refractive power, a sixth lens group G6 with negative refractive power, a seventh lens group G7 with positive refractive power, and an eighth lens group G8 with negative refractive power. 【0099】 When changing magnification 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 third lens group G3 remains fixed relative to the image plane, the fourth lens group G4 moves toward the object, the fifth lens group G5 moves toward the object, the sixth lens group G6 moves toward the object, the seventh lens group G7 moves toward the object, and the eighth lens group G8 remains fixed relative to the image plane. Also, when focusing from an object at infinity to an object at close range, the fifth lens group G5 moves toward the object along the optical axis. 【0100】 The first lens group G1 consists of a cemented lens comprising a negative meniscus lens L1 and a biconvex lens L2, both with their convex surfaces facing the object, and a positive meniscus lens L3 with its convex surface facing the object. 【0101】 The second lens group G2 consists of a cemented lens comprising a biconvex lens L4 and a biconcave lens L5, and a negative meniscus lens L6 with its convex surface facing the object. 【0102】 The third lens group G3 consists of the third lens group G3a with positive refractive power and the third lens group G3b with negative refractive power. The third lens group G3b corresponds to the vibration isolation lens group, and vibration isolation is performed by displacing the third lens group G3b in a direction approximately perpendicular to the optical axis. The third lens group G3a consists of a cemented lens consisting of a biconvex lens L7 and a negative meniscus lens L8 with its convex surface facing the image side, and a positive meniscus lens L9 with its convex surface facing the image side. The third lens group G3b consists of a biconcave lens L10 and a cemented lens consisting of a biconcave lens L11 and a biconvex lens L12. 【0103】 The fourth lens group G4 consists of a biconvex lens L13, a cemented lens comprising a biconvex lens L14 and a negative meniscus lens L15 with its convex surface facing the image side, a positive meniscus lens L16 with its convex surface facing the image side, and a three-element cemented lens comprising a negative meniscus lens L17 with its convex surface facing the object side, a biconvex lens L18, and a biconcave lens L19. An aperture diaphragm S is also provided between the negative meniscus lens L15 and the positive meniscus lens L16. 【0104】 The fifth lens group G5 consists of a positive meniscus lens L20 with its convex surface facing the object. The object-facing surface of the positive meniscus lens L20 has a predetermined aspherical shape. 【0105】 The sixth lens group G6 consists of a biconvex lens L21 and a negative meniscus lens L22 with its convex surface facing the object. 【0106】 The seventh lens group G7 consists of a biconcave lens L23 and a positive meniscus lens L24 with its convex side facing the object. 【0107】 The eighth lens group G8 consists of a positive meniscus lens L25 with its convex surface facing the image side and a negative meniscus lens L26 with its convex surface facing the image side. 【0108】 The specifications of the variable magnification imaging optical system according to Example 2 are shown below. Numerical Example 2 Unit: mm [Surface data] Surface number rd nd vd θgF Object surface ∞ (d0) 1 247.4681 3.0000 1.80450 39.64 0.5715 2 127.9302 10.4047 1.49700 81.61 0.5389 3 -340.7072 0.1500 4 107.2854 6.9314 1.42537 97.80 0.5330 5 340.6600 (d5) 6 330.5688 3.1766 1.78472 25.72 0.6158 7 -457.1933 1.5000 1.87070 40.73 0.5682 8 88.7397 1.2733 9 127.2821 1.5000 1.80610 40.73 0.5672 10 52.9857 (d10) 11 62.4409 6.7109 1.51742 52.15 0.5590 12 -58.7501 0.9000 1.70154 41.15 0.5770 13 -130.7300 0.6000 14 -330.6763 2.5329 1.61340 44.27 0.5633 15 -75.3123 2.1201 16 -91.6685 0.9000 1.69680 55.46 0.5426 17 58.7659 4.1131 18 -37.8938 0.9000 1.59349 67.00 0.5366 19 104.7094 3.0352 1.84666 23.78 0.6192 20 -160.0055 (d20) 21 101.7630 3.1486 1.80809 22.76 0.6287 22 -241.1711 0.1500 23 58.7632 6.1936 1.49700 81.61 0.5389 24 -48.5350 0.9000 2.00100 29.13 0.5995 25 -429.8405 2.9500 26 (aperture) ∞ 7.8860 27 -96.4433 2.5341 1.78472 25.72 0.6158 28 -49.6772 0.3000 29 46.9234 0.9045 1.85896 22.73 0.6284 30 25.2707 8.7731 1.51742 52.15 0.5590 31 -47.6765 0.9000 1.87070 40.73 0.5682 32 313.0319 (d32) 33* 44.6595 3.6222 1.61881 63.85 0.5417 34 628.3647 (d34) 35 102.6917 2.6198 1.77047 29.74 0.5951 36 -428.3588 0.1500 37 45.9840 0.9000 1.90043 37.37 0.5767 38 22.6140 (d38) 39 -47.5082 0.9000 1.41390 101.00 0.5340 40 102.6353 1.7465 41 43.0707 3.6284 1.72825 28.32 0.6059 42 187.4226 (d42) 43 -66.9379 3.0960 1.51823 58.96 0.5442 44 -41.7178 2.3277 45 -36.0309 0.9000 2.00100 29.13 0.5995 46 -71.7248 31.8862 47 ∞ 2.1000 1.51680 64.20 0.5343 48 ∞ (BF) Image plane ∞ [Aspherical data] 33 sides K 0.00000 A4 -5.50723E-07 A6 4.83977E-10 A8 -3.39205E-12 [Various Data] Wide-angle, Medium, Telephoto Focal length 52.00 159.27 485.00 F-numbers: 4.57, 5.68, 6.50 Full angle of view 2ω 45.37 14.97 4.93 Image height Y 21.63 21.63 21.63 Lens length: 270.99 x 313.85 x 357.94 [Variable interval data] Wide-angle, Medium, Telephoto d0 ∞ ∞ ∞ d5 6.3215 69.4587 113.8777 d10 26.0601 5.7786 5.4500 d20 56.2485 30.5454 2.0011 d32 19.9032 23.9955 47.9392 d34 2.9996 4.5307 3.0000 d38 15.5594 14.8795 16.8949 d42 4.6348 25.3944 29.5102 BF 1.0000 0.9999 1.0000 [Lens group data] Group starting plane focal length G1 1 199.03 G2 6 -60.63 G3 11 -120.71 G4 21 63.99 G5 33 77.51 G6 35 -98.40 G7 39 1525.03 G8 43 -112.79 G3a 11 61.30 G3b 16 -36.13 [Examples] 【0109】 Figure 21 is a lens configuration diagram of the variable magnification imaging optical system of Embodiment 3 of the present invention. 【0110】 Starting from the object side, the lens system consists of a first lens group G1 with positive refractive power, a second lens group G2 with negative refractive power, a third lens group G3 with negative refractive power, a fourth lens group G4 with positive refractive power, and a subsequent lens group GR consisting of multiple lens groups. The subsequent lens group GR is composed of a fifth lens group G5 with negative refractive power, a sixth lens group G6 with positive refractive power, and a seventh lens group G7 with negative refractive power. 【0111】 When changing magnification 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 third lens group G3 remains fixed relative to the image plane, the fourth lens group G4 moves toward the object, the fifth lens group G5 moves toward the object, the sixth lens group G6 moves toward the object, and the seventh lens group G7 remains fixed relative to the image plane. Also, when focusing from an object at infinity to an object at close range, the fifth lens group G5 moves toward the image along the optical axis. 【0112】 The first lens group G1 consists of a cemented lens comprising a negative meniscus lens L1 and a biconvex lens L2, both with their convex surfaces facing the object, and a positive meniscus lens L3 with its convex surface facing the object. 【0113】 The second lens group G2 consists of a cemented lens comprising a positive meniscus lens L4 with its convex surface facing the object and a negative meniscus lens L5 with its convex surface facing the object, and a biconcave lens L6. 【0114】 The third lens group G3 consists of the third lens group G3a with positive refractive power and the third lens group G3b with negative refractive power. The third lens group G3b corresponds to the vibration isolation lens group, and vibration isolation is performed by displacing the third lens group G3b in a direction approximately perpendicular to the optical axis. The third lens group G3a consists of a positive meniscus lens L7 with a convex surface facing the image side and a positive meniscus lens L8 with a convex surface facing the object side. The third lens group G3b consists of a biconcave lens L9 and a cemented lens consisting of a biconcave lens L10 and a biconvex lens L11. 【0115】 The fourth lens group G4 consists of a biconvex lens L12, a cemented lens made up of a biconvex lens L13 and a biconcave lens L14, a positive meniscus lens L15 with its convex surface facing the image side, and a three-element cemented lens made up of a negative meniscus lens L16 with its convex surface facing the object side, a biconvex lens L17, and a negative meniscus lens L18 with its convex surface facing the image side. An aperture diaphragm S is also provided between the biconcave lens L14 and the positive meniscus lens L15. 【0116】 The fifth lens group G5 consists of a negative meniscus lens L19 with its convex surface facing the object. 【0117】 The sixth lens group G6 consists of a biconvex lens L20, a negative meniscus lens L21 with its convex surface facing the object, a biconcave lens L22, and a positive meniscus lens L23 with its convex surface facing the object. 【0118】 The seventh lens group G7 consists of a cemented lens comprising a biconvex lens L24 and a biconcave lens L25. 【0119】 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 θgF Object surface ∞ (d0) 1 254.8487 3.0000 1.83481 42.72 0.5647 2 129.9306 10.2096 1.49700 81.61 0.5389 3 -2759.8008 0.1500 4 124.7106 9.6347 1.43700 95.10 0.5336 5 1625.0139 (d5) 6 64.2935 5.5774 1.78472 25.72 0.6158 7 1331.3980 1.5000 1.87070 40.73 0.5682 8 43.0238 6.0943 9 -183.0418 1.5000 1.87070 40.73 0.5682 10 114.5638 (d10) 11 -493.8050 3.7313 1.51742 52.15 0.5590 12 -58.2779 0.1500 13 40.0092 4.9186 1.48749 70.44 0.5306 14 1086.9504 2.6205 15 -204.7742 0.9000 1.72916 54.67 0.5453 16 59.2098 4.2591 17 -47.3799 0.9000 1.59349 67.00 0.5366 18 77.4018 2.9902 1.85451 25.15 0.6103 19 -2456.5532 (d19) 20 298.9698 3.7975 1.80000 29.84 0.6017 21 -97.6294 0.1500 22 60.3214 6.5142 1.58313 59.38 0.5434 23 -44.3952 0.9000 2.05090 26.94 0.6052 24 1755.8067 5.3500 25 (aperture) ∞ 6.8756 26 -202.9982 3.8293 1.80809 22.76 0.6287 27 -52.3651 0.1500 28 42.7613 0.9000 1.84666 23.78 0.6192 29 28.5412 7.5836 1.48749 70.44 0.5306 30 -65.5509 0.9000 1.95375 32.32 0.5901 31 -497.4614 (d31) 32 523.6851 0.9000 1.59349 67.00 0.5366 33 53.3220 (d33) 34 114.3583 3.7271 1.77047 29.74 0.5951 35 -130.1746 0.1500 36 31.9003 0.9000 1.90043 37.37 0.5767 37 22.9949 10.7600 38 -66.9524 0.9000 1.55032 75.50 0.5401 39 73.2906 0.1500 40 35.9786 4.1599 1.72047 34.71 0.5834 41 108.5179 (d41) 42 108.8950 5.9582 1.54814 45.82 0.5700 43 -37.2636 0.9000 1.90043 37.37 0.5767 44 227.4795 31.9944 45 ∞ 2.5000 1.52301 58.59 0.5448 46 ∞ (BF) Image plane ∞ [Various Data] Wide-angle, Medium, Telephoto Focal length 62.10 183.72 578.88 F-numbers: 4.61, 5.54, 6.50 Full angle of view 2ω 38.41 13.09 4.16 Image height Y 21.63 21.63 21.63 Lens length: 293.50, 345.55, 393.20 [Variable interval data] Wide-angle, Medium, Telephoto d0 ∞ ∞ ∞ d5 4.7000 88.1258 142.4388 d10 43.2190 11.8475 5.1773 d19 45.8460 29.6649 2.2554 d31 3.1137 8.2903 3.0000 d33 35.0359 27.8801 57.5014 d41 2.5000 20.6602 23.7387 BF 1.0000 1.0000 1.0000 [Lens group data] Group starting plane focal length G1 1 245.22 G2 6 -51.65 G3 11 -565.97 G4 20 46.64 G5 32 -100.10 G6 34 1930.42 G7 42 -123.05 G3a 11 50.93 G3b 15 -39.62 [Examples] 【0120】 Figure 31 is a lens configuration diagram of the variable magnification imaging optical system of Embodiment 4 of the present invention. 【0121】 Starting from the object side, the lens system consists of a first lens group G1 with positive refractive power, a second lens group G2 with negative refractive power, a third lens group G3 with negative refractive power, a fourth lens group G4 with positive refractive power, and a subsequent lens group GR consisting of multiple lens groups. The subsequent lens group GR is composed of a fifth lens group G5 with negative refractive power, a sixth lens group G6 with positive refractive power, a seventh lens group G7 with negative refractive power, and an eighth lens group G8 with negative refractive power. 【0122】 When changing magnification 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 third lens group G3 remains fixed relative to the image plane, the fourth lens group G4 moves toward the object, the fifth lens group G5 moves toward the object, the sixth lens group G6 moves toward the object, the seventh lens group G7 moves toward the object, and the eighth lens group G8 remains fixed relative to the image plane. Furthermore, when focusing from an object at infinity to an object at close range, the fifth lens group G5 and the sixth lens group G6 move along the optical axis on different trajectories. 【0123】 The first lens group G1 consists of a cemented lens comprising a negative meniscus lens L1 and a biconvex lens L2, both with their convex surfaces facing the object, and a positive meniscus lens L3 with its convex surface facing the object. 【0124】 The second lens group G2 consists of a cemented lens comprising a biconvex lens L4 and a biconcave lens L5, and a biconcave lens L6. 【0125】 The third lens group G3 consists of the third lens group G3a with positive refractive power and the third lens group G3b with negative refractive power. The third lens group G3b corresponds to the vibration isolation lens group, and vibration isolation is performed by displacing the third lens group G3b in a direction approximately perpendicular to the optical axis. The third lens group G3a consists of a biconvex lens L7 and a biconvex lens L8. The third lens group G3b consists of a biconcave lens L9 and a cemented lens consisting of a biconcave lens L10 and a positive meniscus lens L11 with its convex surface facing the object. 【0126】 The fourth lens group G4 is composed of a biconvex lens L12, a cemented lens consisting of a biconvex lens L13 and a biconcave lens L14, a positive meniscus lens L15 with its convex surface facing the image side, a negative meniscus lens L16 with its convex surface facing the object side, a biconvex lens L17, and a cemented lens consisting of three lenses including a negative meniscus lens L19 with its convex surface facing the image side. An aperture stop S is provided between the biconcave lens L14 and the positive meniscus lens L15. 【0127】 The fifth lens group G5 is composed of a negative meniscus lens L19 with its convex surface facing the object side. 【0128】 The sixth lens group G6 is composed of a positive meniscus lens L20 with its convex surface facing the object side. 【0129】 The seventh lens group G7 is composed of a cemented lens consisting of a biconvex lens L21 and a biconcave lens L22, and a biconcave lens L23 and a biconvex lens L24. 【0130】 The eighth lens group G8 is composed of a positive meniscus lens L25 with its convex surface facing the image side and a negative meniscus lens L26 with its convex surface facing the image side. 【0131】 The specifications of the zoom imaging optical system according to Example 4 are shown below. Numerical Example 4 Unit: mm [Surface Data] Surface number r d nd vd θgF Object surface ∞ (d0) 1 260.5699 3.0000 1.80610 40.73 0.5672 2 139.6082 9.7969 1.49700 81.61 0.5389 3 -2045.4673 0.1500 4 131.0395 9.0545 1.43700 95.10 0.5336 5 1264.7705 (d5) 6 139.4704 4.2185 1.84666 23.78 0.6192 7 -319.7880 1.5000 1.87070 40.73 0.5682 8 68.7468 4.0347 9 -374.5964 1.5000 1.87070 40.73 0.5682 10 91.2868 (d10) 11 835.0736 3.8146 1.51742 52.15 0.5590 12 -71.7426 0.1500 13 45.9603 4.8521 1.48749 70.44 0.5306 14 -1168.0592 2.4566 15 -201.2193 0.9000 1.65160 58.54 0.5390 16 62.8843 4.1173 17 -53.0686 0.9000 1.59349 67.00 0.5366 18 69.1899 2.9049 1.85451 25.15 0.6103 19 418.9473 (d19) 20 177.4587 3.8452 1.80000 29.84 0.6017 21 -119.1862 0.1937 22 53.1140 6.4225 1.51823 58.96 0.5442 23 -49.5346 0.9000 2.05090 26.94 0.6052 24 1290.5352 5.3500 25 (aperture) ∞ 6.9409 26 -176.7371 3.5393 1.80809 22.76 0.6287 27 -54.7329 0.1511 28 45.7482 0.9000 1.84666 23.78 0.6192 29 27.1703 7.1830 1.48749 70.44 0.5306 30 -74.5348 0.9000 1.90043 37.37 0.5767 31 -630.8075 (d31) 32 146.3221 0.9000 1.61997 63.88 0.5426 33 45.9781 (d33) 34 49.6094 3.8805 1.71300 53.94 0.5442 35 527.7945 (d35) 36 129.9767 2.6450 1.73037 32.23 0.5899 37 -212.4602 0.9000 1.76385 48.49 0.5589 38 28.6600 4.7020 39 -52.0913 0.9000 1.55032 75.50 0.5401 40 157.6980 0.1500 41 48.1993 5.6711 1.62004 36.30 0.5873 42 -64.9367 (d42) 43 -460.4886 2.8689 1.67270 32.17 0.5963 44 -77.5773 7.3625 45 -43.1958 0.9000 2.05090 26.94 0.6052 46 -156.2930 32.5343 47 ∞ 2.5000 1.52301 58.59 0.5448 48 ∞ (BF) Image plane ∞ [Various Data] Wide-angle, Medium, Telephoto Focal length 61.99 183.72 578.00 F-numbers: 4.57, 5.39, 6.51 Full angle of view 2ω 38.84 13.09 4.16 Image height Y 21.63 21.63 21.63 Overall lens length: 293.50, 345.55, 393.50 [Variable interval data] Wide-angle, Intermediate, Telephoto d0: ∞, ∞, ∞ d5: 5.3621, 90.3620, 143.2716 d10: 43.0385, 10.0900, 5.1290 d19: 51.1048, 32.5022, 2.2877 d31: 3.3237, 3.0000, 3.5884 d33: 24.4020, 21.4116, 50.2110 d35: 7.1605, 10.4747, 3.0000 d42: 2.5181, 21.1207, 29.4220 BF: 1.0000, 1.0000, 1.0000 [Lens group data] Group, Starting surface, Focal length G1: 1, 244.09 G2: 6, -54.21 G3: 11, -762.07 G4: 20, 51.04 G5: 32, -108.52 G6: 34, 76.54 G7: 36, -94.42 G8: 43, -106.02 G3a: 11, 53.22 G3b: 15, -42.27 【Example】 【0132】 Figure 41 is a lens configuration diagram of the zoom imaging optical system according to Example 5 of the present invention. 【0133】 Starting from the object side, the lens system consists of a first lens group G1 with positive refractive power, a second lens group G2 with negative refractive power, a third lens group G3 with negative refractive power, a fourth lens group G4 with positive refractive power, and a subsequent lens group GR consisting of multiple lens groups. The subsequent lens group GR is composed of a fifth lens group G5 with positive refractive power, a sixth lens group G6 with negative refractive power, a seventh lens group G7 with positive refractive power, and an eighth lens group G8 with negative refractive power. 【0134】 When changing magnification 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 third lens group G3 remains fixed relative to the image plane, the fourth lens group G4 moves toward the object, the fifth lens group G5 moves toward the object, the sixth lens group G6 moves toward the object, the seventh lens group G7 moves toward the object, and the eighth lens group G8 remains fixed relative to the image plane. Also, when focusing from an object at infinity to an object at close range, the fifth lens group G5 moves toward the object along the optical axis. 【0135】 The first lens group G1 consists of a cemented lens comprising a negative meniscus lens L1 with its convex surface facing the object and a positive meniscus lens L2 with its convex surface facing the object, and a positive meniscus lens L3 with its convex surface facing the object. 【0136】 The second lens group G2 consists of a cemented lens comprising a biconvex lens L4 and a biconcave lens L5, and a biconcave lens L6. 【0137】 The third lens group G3 consists of the third lens group G3a with positive refractive power and the third lens group G3b with negative refractive power. The third lens group G3b corresponds to the vibration isolation lens group, and vibration isolation is performed by displacing the third lens group G3b in a direction approximately perpendicular to the optical axis. The third lens group G3a consists of a cemented lens consisting of a biconvex lens L7 and a negative meniscus lens L8 with its convex surface facing the image side, and a positive meniscus lens L9 with its convex surface facing the object side. The third lens group G3b consists of a biconcave lens L10 and a cemented lens consisting of a biconcave lens L11 and a biconvex lens L12. 【0138】 The fourth lens group G4 consists of a biconvex lens L13, a cemented lens comprising a biconvex lens L14 and a biconcave lens L15, a positive meniscus lens L16 with its convex surface facing the image side, and a three-element cemented lens comprising a negative meniscus lens L17 with its convex surface facing the object side, a biconvex lens L18, and a biconcave lens L19. An aperture diaphragm S is also provided between the biconcave lens L15 and the positive meniscus lens L16. 【0139】 The fifth lens group G5 consists of a biconvex lens L20. 【0140】 The sixth lens group G6 consists of a biconvex lens L21 and a negative meniscus lens L22 with its convex surface facing the object. 【0141】 The seventh lens group G7 consists of a negative meniscus lens L23 with its convex surface facing the image side, and a biconvex lens L24. 【0142】 The eighth lens group G8 consists of a cemented lens comprising a negative meniscus lens L25 with its convex surface facing the object, a biconvex lens L26, and a biconcave lens L27. 【0143】 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 θgF Object surface ∞ (d0) 1 215.1296 3.0000 1.87070 40.73 0.5682 2 124.8790 9.8003 1.49700 81.61 0.5389 3 3400.0000 0.8633 4 127.1376 9.4372 1.43700 95.10 0.5336 5 2500.0000 (d5) 6 129.3746 4.8627 1.80809 22.76 0.6287 7 -407.0541 1.5000 1.87070 40.73 0.5682 8 58.6936 5.1655 9 -770.1059 1.5000 1.87070 40.73 0.5682 10 174.0071 (d10) 11 499.2646 6.5780 1.51742 52.15 0.5590 12 -34.1285 1.0500 1.68960 31.14 0.6031 13 -51.7326 0.6000 14 39.1873 3.1552 1.51742 52.15 0.5590 15 79.3359 4.3918 16 -223.2457 0.9000 1.59349 67.00 0.5366 17 44.8211 5.6115 18 -37.9862 0.9000 1.59349 67.00 0.5366 19 61.4654 3.6689 1.78880 28.43 0.6009 20 -660.9910 (d20) 21 158.8273 3.6321 1.80518 25.46 0.6157 22 -119.7253 0.1531 23 44.3534 7.0228 1.49700 81.61 0.5389 24 -72.7176 1.0500 2.00100 29.13 0.5995 25 265.8361 3.2654 26 (aperture) ∞ 7.7345 27 -973.4472 2.8587 1.80518 25.46 0.6157 28 -78.9131 0.3000 29 46.8597 1.0000 1.85896 22.73 0.6284 30 23.3106 9.5137 1.51742 52.15 0.5590 31 -53.8014 1.0000 1.88100 40.14 0.5700 32 232.4469 (d32) 33 54.7990 3.4266 1.57135 52.95 0.5553 34 -525.5775 (d34) 35 135.8395 2.5693 1.77047 29.74 0.5951 36 -141.3625 0.1500 37 175.4711 1.0000 1.88100 40.14 0.5700 38 28.5412 (d38) 39 -30.8538 1.0000 1.43700 95.10 0.5336 40 -150.5606 0.1500 41 58.9535 3.9341 1.67270 32.17 0.5963 42 -215.0257 (d42) 43 317.0675 1.0000 1.59282 68.62 0.5440 44 68.5321 5.4149 1.74077 27.76 0.6078 45 -62.0799 1.6099 46 -47.0107 1.0000 2.05090 26.94 0.6052 47 248.7953 32.7606 48 ∞ 2.1000 1.51680 64.20 0.5343 49 ∞ (BF) Image plane ∞ [Various Data] Wide-angle, Medium, Telephoto Focal length 62.00 190.20 580.00 F-numbers: 4.64, 5.51, 6.50 Full angle of view 2ω 38.05 12.64 4.16 Image height Y 21.63 21.63 21.63 Lens length: 295.55 x 349.01 x 394.25 [Variable interval data] Wide-angle, Medium, Telephoto d0 ∞ ∞ ∞ d5 3.6800 87.7853 138.0228 d10 41.7728 11.1333 6.1323 d20 47.3981 27.8969 2.3585 d32 23.9114 21.4930 38.3010 d34 3.0420 6.2734 3.0420 d38 16.0798 15.9858 22.1863 d42 2.0330 20.8151 26.5764 BF 1.0000 1.0000 1.0000 [Lens group data] Group starting plane focal length G1 1 240.93 G2 6 -67.91 G3 11 -140.93 G4 21 58.18 G5 33 87.04 G6 35 -70.17 G7 39 288.00 G8 43 -102.51 G3a 11 61.53 G3b 16 -35.66 [Examples] 【0144】 Figure 51 is a lens configuration diagram of the variable magnification imaging optical system of Embodiment 6 of the present invention. 【0145】 Starting from the object side, the lens system consists of a first lens group G1 with positive refractive power, a second lens group G2 with negative refractive power, a third lens group G3 with negative refractive power, a fourth lens group G4 with positive refractive power, and a subsequent lens group GR consisting of multiple lens groups. The subsequent lens group GR is composed of a fifth lens group G5 with positive refractive power, a sixth lens group G6 with negative refractive power, a seventh lens group G7 with positive refractive power, and an eighth lens group G8 with negative refractive power. 【0146】 When changing magnification 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 third lens group G3 remains fixed relative to the image plane, the fourth lens group G4 moves toward the object, the fifth lens group G5 moves toward the object, the sixth lens group G6 moves toward the object, the seventh lens group G7 moves toward the object, and the eighth lens group G8 remains fixed relative to the image plane. Also, when focusing from an object at infinity to an object at close range, the fifth lens group G5 moves toward the object along the optical axis. 【0147】 The first lens group G1 consists of a cemented lens comprising a negative meniscus lens L1 with its convex surface facing the object and a positive meniscus lens L2 with its convex surface facing the object, and a positive meniscus lens L3 with its convex surface facing the object. 【0148】 The second lens group G2 consists of a cemented lens comprising a biconvex lens L4 and a biconcave lens L5, and a biconcave lens L6. 【0149】 The third lens group G3 consists of the third lens group G3a with positive refractive power and the third lens group G3b with negative refractive power. The third lens group G3b corresponds to the vibration isolation lens group, and vibration isolation is performed by displacing the third lens group G3b in a direction approximately perpendicular to the optical axis. The third lens group G3a consists of a cemented lens consisting of a biconvex lens L7 and a negative meniscus lens L8 with its convex surface facing the image side, and a positive meniscus lens L9 with its convex surface facing the object side. The third lens group G3b consists of a biconcave lens L10 and a cemented lens consisting of a biconcave lens L11 and a biconvex lens L12. 【0150】 The fourth lens group G4 consists of a biconvex lens L13, a cemented lens comprising a biconvex lens L14 and a biconcave lens L15, a positive meniscus lens L16 with its convex surface facing the image side, and a three-element cemented lens comprising a negative meniscus lens L17 with its convex surface facing the object side, a biconvex lens L18, and a biconcave lens L19. An aperture diaphragm S is also provided between the biconcave lens L15 and the positive meniscus lens L16. 【0151】 The fifth lens group G5 consists of a cemented lens comprising a negative meniscus lens L20 with its convex surface facing the object and a biconvex lens L21. 【0152】 The sixth lens group G6 consists of a biconvex lens L22 and a negative meniscus lens L23 with its convex surface facing the object. 【0153】 The seventh lens group G7 consists of a negative meniscus lens L24 with its convex surface facing the image side, and a biconvex lens L25. 【0154】 The eighth lens group G8 consists of a cemented lens comprising a biconcave lens L26 and a biconvex lens L27, and a negative meniscus lens L28 with its convex surface facing the image side. 【0155】 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 θgF Object surface ∞ (d0) 1 212.6095 3.0000 1.87070 40.73 0.5682 2 123.9388 9.8021 1.49700 81.61 0.5389 3 2764.4455 0.2101 4 126.9456 9.4427 1.43700 95.10 0.5336 5 2500.0000 (d5) 6 137.6864 4.8176 1.80809 22.76 0.6287 7 -350.3252 1.5000 1.87070 40.73 0.5682 8 60.3571 5.4626 9 -351.3250 1.5000 1.87070 40.73 0.5682 10 239.8547 (d10) 11 523.6759 6.6465 1.51742 52.15 0.5590 12 -34.1871 0.9284 1.68960 31.14 0.6031 13 -50.9216 0.6000 14 38.8202 3.2437 1.51742 52.15 0.5590 15 84.1155 4.4366 16 -169.0366 0.9000 1.59349 67.00 0.5366 17 44.2243 5.4148 18 -39.9971 0.9000 1.59349 67.00 0.5366 19 58.5110 3.6300 1.78880 28.43 0.6009 20 -1381.9873 (d20) 21 144.5152 3.6359 1.80518 25.46 0.6157 22 -127.0864 0.1983 23 44.8136 6.8960 1.49700 81.61 0.5389 24 -72.3187 1.6179 2.00100 29.13 0.5995 25 250.8711 3.2802 26 (aperture) ∞ 8.1844 27 -6678.1063 2.9139 1.80518 25.46 0.6157 28 -79.5642 0.3000 29 47.0059 1.0000 1.85896 22.73 0.6284 30 23.0882 9.3677 1.51742 52.15 0.5590 31 -54.3406 0.9000 1.88100 40.14 0.5700 32 202.7394 (d32) 33 52.1345 0.8000 1.54814 45.82 0.5700 34 31.6445 4.3989 1.57099 50.80 0.5588 35 -959.4267 (d35) 36 114.4601 2.5986 1.77047 29.74 0.5951 37 -177.8043 0.2783 38 156.2465 0.9150 1.88100 40.14 0.5700 39 27.5435 (d39) 40 -34.6676 0.9000 1.43700 95.10 0.5336 41 -267.3057 0.1500 42 53.4022 3.8925 1.67270 32.17 0.5963 43 -552.5330 (d43) 44 -535.8164 1.0133 1.59282 68.62 0.5440 45 85.5612 5.9237 1.74077 27.76 0.6078 46 -46.1697 1.6349 47 -38.2166 0.9000 2.05090 26.94 0.6052 48 -757.8533 30.3841 49 ∞ 2.1000 1.51680 64.20 0.5343 50 ∞ (BF) Image plane ∞ [Various Data] Wide-angle, Medium, Telephoto Focal length 62.00 190.61 580.00 F-numbers: 4.63, 5.52, 6.50 Full angle of view 2ω 38.17 12.61 4.15 Image height Y 21.63 21.63 21.63 Lens length: 295.52 x 348.34 x 394.65 [Variable interval data] Wide-angle, Medium, Telephoto d0 ∞ ∞ ∞ d5 4.1846 88.2169 138.5203 d10 40.8897 9.6778 5.6802 d20 47.1676 28.1325 2.4339 d32 23.9430 20.6453 39.3465 d35 3.0473 6.3211 3.0389 d39 15.8656 14.7248 20.7983 d43 2.8055 23.0052 27.2114 BF 1.0000 1.0000 1.0000 [Lens group data] Group starting plane focal length G1 1 240.99 G2 6 -67.84 G3 11 -144.19 G4 21 58.96 G5 33 84.71 G6 36 -67.91 G7 40 335.19 G8 44 -114.78 G3a 11 59.15 G3b 16 -34.72 [Examples] 【0156】 Figure 61 is a lens configuration diagram of the variable magnification imaging optical system of Embodiment 7 of the present invention. 【0157】 Starting from the object side, the lens system consists of a first lens group G1 with positive refractive power, a second lens group G2 with negative refractive power, a third lens group G3 with negative refractive power, a fourth lens group G4 with positive refractive power, and a subsequent lens group GR consisting of multiple lens groups. The subsequent lens group GR is composed of a fifth lens group G5 with positive refractive power, a sixth lens group G6 with negative refractive power, a seventh lens group G7 with positive refractive power, and an eighth lens group G8 with negative refractive power. 【0158】 When changing magnification 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 third lens group G3 remains fixed relative to the image plane, the fourth lens group G4 moves toward the object, the fifth lens group G5 moves toward the object, the sixth lens group G6 moves toward the object, the seventh lens group G7 moves toward the object, and the eighth lens group G8 remains fixed relative to the image plane. Also, when focusing from an object at infinity to an object at close range, the fifth lens group G5 moves toward the object along the optical axis. 【0159】 The first lens group G1 consists of a cemented lens comprising a negative meniscus lens L1 and a biconvex lens L2, both with their convex surfaces facing the object, and a positive meniscus lens L3 with its convex surface facing the object. 【0160】 The second lens group G2 consists of a cemented lens comprising a biconvex lens L4 and a biconcave lens L5, and a negative meniscus lens L6 with its convex surface facing the object. 【0161】 The third lens group G3 consists of the third lens group G3a with positive refractive power and the third lens group G3b with negative refractive power. The third lens group G3b corresponds to the vibration isolation lens group, and vibration isolation is performed by displacing the third lens group G3b in a direction approximately perpendicular to the optical axis. The third lens group G3a consists of a cemented lens consisting of a biconvex lens L7 and a negative meniscus lens L8 with its convex surface facing the image side, and a positive meniscus lens L9 with its convex surface facing the object side. The third lens group G3b consists of a biconcave lens L10 and a cemented lens consisting of a biconcave lens L11 and a biconvex lens L12. 【0162】 The fourth lens group G4 consists of a biconvex lens L13, a cemented lens comprising a biconvex lens L14 and a biconcave lens L15, a positive meniscus lens L16 with its convex surface facing the image side, and a three-element cemented lens comprising a negative meniscus lens L17 with its convex surface facing the object side, a biconvex lens L18, and a biconcave lens L19. An aperture diaphragm S is also provided between the biconcave lens L15 and the positive meniscus lens L16. 【0163】 The fifth lens group G5 consists of a positive meniscus lens L20 with its convex surface facing the object. 【0164】 The sixth lens group G6 consists of a biconvex lens L21 and a negative meniscus lens L22 with its convex surface facing the object. 【0165】 The seventh lens group G7 consists of a biconcave lens L23 and a positive meniscus lens L24 with its convex side facing the object. 【0166】 The eighth lens group G8 consists of a cemented lens comprising a negative meniscus lens L25 with its convex surface facing the object, a biconvex lens L26, and a biconcave lens L27. 【0167】 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 θgF Object surface ∞ (d0) 1 288.3149 3.0000 1.87070 40.73 0.5682 2 149.5726 9.3709 1.55032 75.50 0.5401 3 -1694.2256 0.1500 4 149.0104 8.3485 1.41390 101.00 0.5340 5 3471.9217 (d5) 6 232.8959 4.1854 1.80000 29.84 0.6017 7 -355.3672 1.5000 1.87070 40.73 0.5682 8 93.3943 3.1089 9 410.7374 1.5000 1.87070 40.73 0.5682 10 93.1779 (d10) 11 133.7607 7.2377 1.51742 52.15 0.5590 12 -39.8480 0.9000 1.70154 41.15 0.5770 13 -59.6229 0.6000 14 41.6569 2.6540 1.58144 40.89 0.5767 15 55.1781 5.1172 16 -243.5081 0.9000 1.59349 67.00 0.5366 17 49.3703 4.9377 18 -41.2902 0.9000 1.59349 67.00 0.5366 19 73.5371 3.3426 1.78472 25.72 0.6158 20 -569.2055 (d20) 21 99.9463 3.6422 1.76182 26.61 0.6123 22 -219.5506 2.0857 23 42.6965 8.1167 1.49700 81.61 0.5389 24 -65.5899 0.9000 1.90366 31.32 0.5948 25 168.7356 8.0360 26 (aperture) ∞ 2.3176 27 -315.3672 2.9407 1.85478 24.80 0.6122 28 -68.2304 0.1501 29 48.2213 0.9000 1.84666 23.78 0.6192 30 22.7765 8.3177 1.51742 52.15 0.5590 31 -46.4260 0.9000 1.87070 40.73 0.5682 32 224.4209 (d32) 33 56.5454 3.0658 1.69680 55.46 0.5426 34 774.8517 (d34) 35 85.3491 2.5822 1.73800 32.33 0.5900 36 -495.9109 0.1500 37 117.3577 0.9000 1.76385 48.49 0.5589 38 25.3401 (d38) 39 -61.3710 0.9005 1.43700 95.10 0.5336 40 200.4033 0.1767 41 44.7870 3.1319 1.67270 32.17 0.5963 42 186.1613 (d42) 43 259.7717 0.9000 1.59282 68.62 0.5440 44 31.4221 9.1721 1.64769 33.84 0.5924 45 -32.3020 0.1501 46 -32.8147 0.9000 2.05090 26.94 0.6052 47 628.2881 29.9255 48 ∞ 2.1000 1.51680 64.20 0.5343 49 ∞ (BF) Image plane ∞ [Various Data] Wide-angle, Medium, Telephoto Focal length 62.00 199.60 673.00 F-number 4.83 6.11 7.37 Full angle of view 2ω 38.02 11.92 3.55 Image height Y 21.63 21.63 21.63 Lens length: 306.97 x 371.31 x 422.13 [Variable interval data] Wide-angle, Medium, Telephoto d0 ∞ ∞ ∞ d5 2.6800 94.1396 152.8706 d10 38.8614 11.7396 3.8305 d20 61.6871 34.4471 2.0000 d32 29.6237 31.0729 54.0507 d34 3.0044 5.7546 3.0037 d38 17.1585 9.9554 9.1333 d42 2.8451 33.0886 46.1311 BF 1.0000 1.0000 1.0000 [Lens group data] Group starting plane focal length G1 1 260.18 G2 6 -75.20 G3 11 -156.73 G4 21 65.36 G5 33 87.38 G6 35 -77.37 G7 39 453.64 G8 43 -108.89 G3a 11 68.23 G3b 16 -39.23 [Examples] 【0168】 Figure 71 is a lens configuration diagram of the variable magnification imaging optical system of Embodiment 8 of the present invention. 【0169】 Starting from the object side, the lens system consists of a first lens group G1 with positive refractive power, a second lens group G2 with negative refractive power, a third lens group G3 with negative refractive power, a fourth lens group G4 with positive refractive power, and a subsequent lens group GR consisting of multiple lens groups. The subsequent lens group GR is composed of a fifth lens group G5 with positive refractive power, a sixth lens group G6 with negative refractive power, a seventh lens group G7 with positive refractive power, and an eighth lens group G8 with negative refractive power. 【0170】 When changing magnification 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 third lens group G3 remains fixed relative to the image plane, the fourth lens group G4 moves toward the object, the fifth lens group G5 moves toward the object, the sixth lens group G6 moves toward the object, the seventh lens group G7 moves toward the object, and the eighth lens group G8 remains fixed relative to the image plane. Also, when focusing from an object at infinity to an object at close range, the fifth lens group G5 moves toward the object along the optical axis. 【0171】 The first lens group G1 consists of a cemented lens comprising a negative meniscus lens L1 and a biconvex lens L2, both with their convex surfaces facing the object, and a positive meniscus lens L3 with its convex surface facing the object. 【0172】 The second lens group G2 consists of a cemented lens comprising a biconvex lens L4 and a biconcave lens L5, and a biconcave lens L6. 【0173】 The third lens group G3 consists of the third lens group G3a with positive refractive power and the third lens group G3b with negative refractive power. The third lens group G3b corresponds to the vibration isolation lens group, and vibration isolation is performed by displacing the third lens group G3b in a direction approximately perpendicular to the optical axis. The third lens group G3a consists of a cemented lens consisting of a positive meniscus lens L7 with a convex surface facing the image side and a negative meniscus lens L8 with a convex surface facing the image side, and a positive meniscus lens L9 with a convex surface facing the object side. The third lens group G3b consists of a biconcave lens L10 and a cemented lens consisting of a biconcave lens L11 and a biconvex lens L12. 【0174】 The fourth lens group G4 consists of a biconvex lens L13, a cemented lens consisting of a biconvex lens L14 and a biconcave lens L15, a biconvex lens L16, and a three-element cemented lens consisting of a negative meniscus lens L17 with its convex surface facing the object, a biconvex lens L18, and a biconcave lens L19. In addition, an aperture diaphragm S is provided adjacent to the object side of the biconvex lens L13. 【0175】 The fifth lens group G5 consists of a biconvex lens L20. 【0176】 The sixth lens group G6 consists of a biconvex lens L21 and a negative meniscus lens L22 with its convex surface facing the object. 【0177】 The seventh lens group G7 consists of a negative meniscus lens L23 with its convex surface facing the image side and a positive meniscus lens L24 with its convex surface facing the object side. 【0178】 The eighth lens group G8 consists of a cemented lens comprising a negative meniscus lens L25 with its convex surface facing the object, a biconvex lens L26, and a biconcave lens L27. 【0179】 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 θgF Object surface ∞ (d0) 1 233.8673 3.0000 1.80610 40.73 0.5672 2 132.8985 9.9988 1.39395 106.47 0.5351 3 -2239.1599 0.1500 4 133.3062 9.0990 1.49700 81.61 0.5389 5 3139.8567 (d5) 6 191.5776 4.8721 1.80809 22.76 0.6287 7 -221.4702 1.5000 1.87070 40.73 0.5682 8 69.6233 4.6045 9 -631.8719 1.5000 1.83481 42.72 0.5647 10 192.5478 (d10) 11 -982.3179 5.8578 1.51742 52.15 0.5590 12 -31.5180 0.9032 1.68430 26.81 0.6232 13 -45.6983 0.1500 14 38.0925 3.7863 1.51680 64.20 0.5343 15 107.1068 3.8659 16 -301.8209 0.9000 1.61999 69.35 0.5336 17 41.9279 5.4723 18 -35.4782 0.9000 1.61999 69.35 0.5336 19 61.9383 3.3888 1.85478 24.80 0.6122 20 -5009.4928 (d20) 21 (aperture) ∞ 2.0000 22 143.2232 3.5559 1.80809 22.76 0.6287 23 -135.2310 0.1686 24 43.1764 6.2997 1.49700 81.61 0.5389 25 -81.3409 0.9000 2.10092 26.11 0.6078 26 626.6190 10.3300 27 442.1398 2.9709 1.85451 25.15 0.6103 28 -105.9296 0.1500 29 46.4655 0.9005 1.84666 23.78 0.6192 30 21.4774 8.2088 1.51823 58.96 0.5442 31 -57.0767 0.9000 1.87070 40.73 0.5682 32 170.9855 (d32) 33 46.7238 3.4782 1.51742 52.15 0.5590 34 -1945.6113 (d34) 35 125.5970 2.5815 1.85451 25.15 0.6103 36 -137.5059 0.1500 37 323.2397 0.9000 1.80450 39.64 0.5715 38 25.3518 (d38) 39 -32.6591 1.0729 1.39395 106.47 0.5351 40 -179.5020 0.1525 41 47.7598 3.4680 1.68960 31.14 0.6031 42 502.4743 (d42) 43 121.0655 0.9000 1.76385 48.49 0.5589 44 37.0989 7.9505 1.69895 30.05 0.6029 45 -36.1172 0.3719 46 -34.8818 0.9000 2.10092 26.11 0.6078 47 432.6792 29.9324 48 ∞ 2.1000 1.51680 64.20 0.5343 49 ∞ (BF) Image plane ∞ [Various Data] Wide-angle, Medium, Telephoto Focal length 60.82 189.04 583.76 F-numbers: 4.75, 5.54, 6.49 Full angle of view 2ω 38.74 12.65 4.11 Image height Y 21.63 21.63 21.63 Lens length: 291.38 x 346.88 x 391.12 [Variable interval data] Wide-angle, Medium, Telephoto d0 ∞ ∞ ∞ d5 2.6821 90.8307 143.8117 d10 45.5805 12.9318 4.1835 d20 44.9798 26.4317 3.0975 d32 24.0633 21.4581 39.4876 d34 3.0580 7.1768 3.0634 d38 17.5883 16.9350 21.9052 d42 2.1406 19.8284 24.2763 BF 1.0000 1.0000 1.0000 [Lens group data] Group starting plane focal length G1 1 244.99 G2 6 -70.36 G3 11 -128.69 G4 21 55.65 G5 33 88.24 G6 35 -63.66 G7 39 296.44 G8 43 -104.87 G3a 11 54.74 G3b 16 -31.70 【0180】 The following is a list of corresponding values ​​for the conditional expressions in each of the above embodiments. [Conditional expression corresponding value] Conditional Expression / Examples ex1 ex2 ex3 ex4 (1) 4.0<β2T / β2W<15.0 7.3 10.2 5.5 5.6 (2) -15.0 <fT / f2<-5.0 -9.1 -8.0 -11.2 -10.7 (3) -8.0 <fT / f3<0.0 -3.6 -4.0 -1.0 -0.8 (4) 5.0 <fT / f3a<15.0 9.9 7.9 11.4 10.9 (5)3.5<|(1-βosT)×βRosT|<10.0 5.1 4.5 4.7 4.5 (6) -25.0 <fT / fos<-10.0 -15.9 -13.4 -14.6 -13.7 (7) νdosn-νdosp>30.0 36.8 37.4 35.7 37.6 (8) 4.0 <fT / f4<18.0 9.6 7.6 12.4 11.3 (9) *1 5.0 4.9 6.3 5.2 (10) 2.5 <EXPT / Ymax<6.0 4.2 4.5 4.2 4.2 (11) 1.0 <fT / f1<4.0 2.4 2.4 2.4 2.4 (12) νdmax1p>85.0 95.1 97.8 95.1 95.1 (13) *2 0.056 0.061 0.056 0.056 (14) 0.40 <LTT / fT<0.85 0.68 0.74 0.68 0.68 Conditional Expression / Examples ex5 ex6 ex7 ex8 (1) 4.0<β2T / β2W<15.0 8.8 8.9 9.8 10.0 (2) -15.0 <fT / f2<-5.0 -8.5 -8.5 -8.9 -8.3 (3) -8.0 <fT / f3<0.0 -4.1 -4.0 -4.3 -4.5 (4) 5.0 <fT / f3a<15.0 9.4 9.8 9.9 10.7 (5)3.5<|(1-βosT)×βRosT|<10.0 5.1 5.2 5.3 5.6 (6) -25.0 <fT / fos<-10.0 -16.3 -16.7 -17.2 -18.4 (7) νdosn-νdosp>30.0 38.6 38.6 41.3 44.6 (8) 4.0 <fT / f4<18.0 10.0 9.8 10.3 10.5 (9) *1 5.2 5.1 5.3 5.1 (10) 2.5 <EXPT / Ymax<6.0 4.1 4.2 4.2 4.1 (11) 1.0 <fT / f1<4.0 2.4 2.4 2.6 2.4 (12) νdmax1p>85.0 95.1 95.1 101.0 106.5 (13) *2 0.056 0.056 0.068 0.078 (14) 0.40 <LTT / fT<0.85 0.68 0.68 0.63 0.67 *1 is 3.5 < |(1-βfocT^2)×βRfocT^2| < 10.0 *2 is θgFmax1p - 0.6483 + 0.0018 × νdmax1p > 0.040 【0181】 <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 each of 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. 【0182】 Furthermore, although the above embodiments and examples have described a configuration consisting of substantially seven or eight lens groups, a configuration including an additional lens that substantially has no refractive power is also possible. 【0183】 This technology can take the following configuration. [1] Starting from the object side and moving towards the image side, the lens system consists of a first lens group with positive refractive power, a second lens group with negative refractive power, a third lens group with negative refractive power, a fourth lens group with positive refractive power, and a subsequent lens group consisting of multiple lens groups. When zooming from the wide-angle end to the telephoto end, the spacing between adjacent lens groups changes, the first lens group moves toward the object, and the second lens group moves toward the image. The third lens group has a group of vibration-damping lenses with negative refractive power, Vibration isolation is performed by displacing the aforementioned vibration-damping lens group in a direction substantially perpendicular to the optical axis, thereby moving the image perpendicular to the optical axis. The aforementioned group of subsequent lenses includes a group of focusing lenses that move when focusing from an object at infinity to an object at a close distance. The aforementioned focusing lens group is characterized by comprising two or fewer lenses, thereby enabling variable magnification imaging. [2] The second lens group comprises at least two negative lenses and at least one positive lens. The variable magnification imaging optical system described in [1] is characterized by satisfying the following conditional equation. (1) 4.0 < β2T / β2W < 15.0 (2) -15.0 <fT / f2<-5.0 however, β2T: Lateral magnification of the second lens group when focused at infinity at the telephoto end. β2W: Lateral magnification of the second lens group when focused at infinity at the wide-angle end. fT: Total focal length of the lens system when focused at infinity at the telephoto end. f2: Focal length of the second lens group [3] The third lens group consists of a third a lens group with positive refractive power and a third b lens group with negative refractive power, in order from the object side to the image side. The third b lens group is used as an anti-vibration lens group and is displaced in a direction approximately perpendicular to the optical axis, thereby performing vibration isolation by moving the image in a direction perpendicular to the optical axis. A variable-magnification imaging optical system according to [1] or [2], characterized by satisfying the following conditional formula. (3) -8.0 <fT / f3<0.0 (4) 5.0 <fT / f3a<15.0 however, fT: Total focal length of the lens system when focused at infinity at the telephoto end. f3: Focal length of the third lens group f3a: Focal length of the aforementioned 3a lens group [4] The aforementioned image-stabilizing lens group is fixed to the image plane when the magnification changes from the wide-angle end to the telephoto end, and consists of two negative lenses and one positive lens. A variable magnification imaging optical system according to any one of [1] to [3], characterized by satisfying the following conditional equations. (5) 3.5<|(1-βosT)×βRosT|<10.0 (6) -25.0 <fT / fos<-10.0 (7) νdosn-νdosp>30.0 however, βosT: Lateral magnification of the image-stabilizing lens group when focused at infinity at the telephoto end. βRosT: Lateral magnification of the lens system located on the image side of the aforementioned image-stabilizing lens group when focusing at infinity at the telephoto end. fT: Total focal length of the lens system when focused at infinity at the telephoto end. fos: Focal length of the aforementioned image-stabilizing lens group νdosn: The average value of the Abbe numbers for the d line of the two negative lenses included in the vibration-damping lens group. νdosp: Abbe number of one positive lens included in the vibration-damping lens group with respect to the d line. [5] The fourth lens group has an aperture diaphragm, A variable-magnification imaging optical system according to any one of [1] to [4], characterized in that it satisfies the following conditional equations. (8) 4.0 <fT / f4<18.0 however, fT: Total focal length of the lens system when focused at infinity at the telephoto end. f4: Focal length of the fourth lens group [6] The aforementioned focusing lens group consists of one lens or one set of cemented lenses. A variable magnification imaging optical system according to any one of [1] to [5], characterized by satisfying the following conditional formulas. (9) 3.5<|(1-βfocT^2)×βRfocT^2|<10.0 however, βfocT: Lateral magnification of the focusing lens group when infinity focus is achieved at the telephoto end. βRfocT: Lateral magnification of the lens system located on the image side of the focusing lens group when infinity focus is achieved at the telephoto end. [7] The aforementioned successor lens group has at least three lens groups whose spacing from each other changes when the magnification changes from the wide-angle end to the telephoto end, and has an image-side lens group with negative refractive power closest to the image. The aforementioned image-side lens group is fixed to the image plane when changing magnification from the wide-angle end to the telephoto end, and when focusing from an object at infinity to an object at close range. A variable magnification imaging optical system according to any one of [1] to [6], characterized in that it satisfies the following conditional formulas. (10) 2.5 <EXPT / Ymax<6.0 however, EXPT: Distance from the exit pupil position to the image plane when focusing at infinity at the telephoto end. Ymax: Maximum image height [8] The first lens group consists of one negative lens and two positive lenses. A variable magnification imaging optical system according to any one of [1] to [7], characterized in that it satisfies the following conditional formulas. (11) 1.0 <fT / f1<4.0 (12) νdmax1p>85.0 (13) θgFmax1p-0.6483+0.0018×νdmax1p>0.040 (14) 0.40 <LTT / fT<0.85 however, fT: Total focal length of the lens system when focused at infinity at the telephoto end. f1: Focal length of the first lens group νdmax1p: The Abbe number for the d line of the positive lens with the largest Abbe number among the positive lenses in the first lens group. θgFmax1p: The partial dispersion ratio of the g-line and F-line of the positive lens with the largest Abbe number among the positive lenses in the first lens group. LTT: The length from the object-side lens plane to the image plane of the entire lens system when focused at infinity at the telephoto end. [Explanation of symbols] 【0184】 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 GR successor lens series G3a 3a lens group G3b 3b lens group S Aperture diaphragm FL Optical Filter I image plane

Claims

[Claim 1] Starting from the object side and moving towards the image side, the lens system consists of a first lens group with positive refractive power, a second lens group with negative refractive power, a third lens group with negative refractive power, a fourth lens group with positive refractive power, and a subsequent lens group consisting of multiple lens groups. When zooming from the wide-angle end to the telephoto end, the spacing between adjacent lens groups changes, the first lens group moves towards the object, and the second lens group moves towards the image. The third lens group has a group of vibration-damping lenses with negative refractive power, Vibration isolation is performed by displacing the aforementioned vibration-damping lens group in a direction substantially perpendicular to the optical axis, thereby moving the image perpendicular to the optical axis. The aforementioned successor lens group has a focusing lens group that moves when focusing from an object at infinity to an object at close range, and has at least three lens groups whose spacing from each other changes when zooming from the wide-angle end to the telephoto end, and has an image-side lens group with negative refractive power closest to the image, and the image-side lens group is fixed to the image plane when focusing from an object at infinity to an object at close range. The aforementioned focusing lens group is characterized by comprising two or fewer lenses, thereby enabling variable magnification imaging. [Claim 2] Starting from the object side and moving towards the image side, the lens system consists of a first lens group with positive refractive power, a second lens group with negative refractive power, a third lens group with negative refractive power, a fourth lens group with positive refractive power, and a subsequent lens group consisting of multiple lens groups. When zooming from the wide-angle end to the telephoto end, the spacing between adjacent lens groups changes, the first lens group moves towards the object, and the second lens group moves towards the image. The third lens group has a group of vibration-damping lenses with negative refractive power, Vibration isolation is performed by displacing the aforementioned vibration-damping lens group in a direction substantially perpendicular to the optical axis, thereby moving the image perpendicular to the optical axis. The second lens group comprises at least two negative lenses and at least one positive lens. The aforementioned successor lens group has a focusing lens group that moves when focusing from an object at infinity to an object at a close distance, and has at least three lens groups whose spacing from each other changes when zooming from the wide-angle end to the telephoto end. The aforementioned focusing lens group consists of two or fewer lenses. A variable-magnification imaging optical system characterized by satisfying the following conditional equation. (12) νdmax1p>85.0 (13) θgFmax1p-0.6483+0.0018×νdmax1p>0.040 νdmax1p: The Abbe number for the d line of the positive lens with the largest Abbe number among the positive lenses in the first lens group. θgFmax1p: The partial dispersion ratio of the g-line and F-line of the positive lens with the largest Abbe number among the positive lenses in the first lens group. [Claim 3] The second lens group comprises at least two negative lenses and at least one positive lens. The variable magnification imaging optical system according to claim 1, characterized in that it satisfies the following conditional formula. (1) 4.0<β2T / β2W<15.0 (2) -15.0<fT / f2<-5.0 however, β2T: Lateral magnification of the second lens group when infinity focus is achieved at the telephoto end. β2W: Lateral magnification of the second lens group when focused at infinity at the wide-angle end. fT: Focal length of the entire lens system when focused at infinity at the telephoto end. f2: Focal length of the second lens group [Claim 4] The variable magnification imaging optical system according to claim 2, characterized in that it satisfies the following conditional formula. (1) 4.0<β2T / β2W<15.0 (2) -15.0<fT / f2<-5.0 however, β2T: Lateral magnification of the second lens group when infinity focus is achieved at the telephoto end. β2W: Lateral magnification of the second lens group when focused at infinity at the wide-angle end. fT: Focal length of the entire lens system when focused at infinity at the telephoto end. f2: Focal length of the second lens group [Claim 5] The third lens group consists of a third a lens group with positive refractive power and a third b lens group with negative refractive power, in order from the object side to the image side. The third b lens group is used as an anti-vibration lens group and is displaced in a direction approximately perpendicular to the optical axis, thereby performing vibration isolation by moving the image in a direction perpendicular to the optical axis. A variable magnification imaging optical system according to claim 1 or 2, characterized in that it satisfies the following conditional formula. (3) -8.0<fT / f3<0.0 (4) 5.0<fT / f3a<15.0 however, fT: Focal length of the entire lens system when focused at infinity at the telephoto end. f3: Focal length of the third lens group f3a: Focal length of the 3a lens group [Claim 6] The aforementioned image-stabilizing lens group is fixed to the image plane when the magnification changes from the wide-angle end to the telephoto end, and consists of two negative lenses and one positive lens. A variable magnification imaging optical system according to claim 1 or 2, characterized in that it satisfies the following conditional formula. (5) 3.5<|(1-βosT)×βRosT|<10.0 (6) -25.0<fT / fos<-10.0 (7) νdosn−νdosp>30.0 however, βosT: Lateral magnification of the image-stabilizing lens group when focused at infinity at the telephoto end. βRosT: Lateral magnification of the lens system located on the image side of the aforementioned image-stabilizing lens group when focusing at infinity at the telephoto end. fT: Focal length of the entire lens system when focused at infinity at the telephoto end. fos: Focal length of the aforementioned vibration-damping lens group νdosn: The average value of the Abbe numbers for the d-line of the two negative lenses included in the vibration-damping lens group. νdosp: Abbe number of one positive lens included in the vibration-damping lens group with respect to the d line. [Claim 7] The fourth lens group has an aperture diaphragm, A variable magnification imaging optical system according to claim 1 or 2, characterized in that it satisfies the following conditional formula. (8) 4.0<fT / f4<18.0 however, fT: Focal length of the entire lens system when focused at infinity at the telephoto end. f4: Focal length of the fourth lens group [Claim 8] The aforementioned focusing lens group consists of one lens or one set of cemented lenses. A variable magnification imaging optical system according to claim 1 or 2, characterized in that it satisfies the following conditional formula. (9) 3.5<|(1-βfocT^2)×βRfocT^2|<10.0 however, βfocT: Lateral magnification of the focusing lens group when infinity focus is achieved at the telephoto end. βRFocT: Lateral magnification of the lens system located on the image side of the focusing lens group when infinity focus is achieved at the telephoto end. [Claim 9] The aforementioned image-side lens group is fixed to the image plane when the magnification is changed from the wide-angle end to the telephoto end. The variable magnification imaging optical system according to claim 1, characterized in that it satisfies the following conditional formula. (10) 2.5<EXPT / Ymax<6.0 however, EXPT: Distance from the exit pupil position to the image plane when infinity focus is achieved at the telephoto end. Ymax: Maximum image height [Claim 10] The aforementioned successor lens group has an image-side lens group with the most negative refractive power on the image side, The aforementioned image-side lens group is fixed to the image plane when changing magnification from the wide-angle end to the telephoto end, and when focusing from an object at infinity to an object at close range. The variable magnification imaging optical system according to claim 2, characterized in that it satisfies the following conditional formula. (10) 2.5<EXPT / Ymax<6.0 however, EXPT: Distance from the exit pupil position to the image plane when infinity focus is achieved at the telephoto end. Ymax: Maximum image height [Claim 11] The first lens group consists of one negative lens and two positive lenses. The variable magnification imaging optical system according to claim 1, characterized in that it satisfies the following conditional formula. (11) 1.0<fT / f1<4.0 (12) νdmax1p>85.0 (13) θgFmax1p-0.6483+0.0018×νdmax1p>0.040 (14) 0.40<LTT / fT<0.85 however, fT: Focal length of the entire lens system when focused at infinity at the telephoto end. f1: Focal length of the first lens group νdmax1p: The Abbe number for the d line of the positive lens with the largest Abbe number among the positive lenses in the first lens group. θgFmax1p: The partial dispersion ratio of the g-line and F-line of the positive lens with the largest Abbe number among the positive lenses in the first lens group. LTT: The length from the lens surface closest to the object to the image plane of the entire lens system when focused at infinity at the telephoto end. [Claim 12] The first lens group consists of one negative lens and two positive lenses. The variable magnification imaging optical system according to claim 2, characterized in that it satisfies the following conditional formula. (11) 1.0<fT / f1<4.0 (14) 0.40<LTT / fT<0.85 however, fT: Focal length of the entire lens system when focused at infinity at the telephoto end. f1: Focal length of the first lens group LTT: The length from the lens surface closest to the object to the image plane of the entire lens system when focused at infinity at the telephoto end.

Images