Zoom optical system, optical device, and method of manufacturing zoom optical system

Abstract

To provide a zoom optical system which offers good optical performance, an optical device, and a method of manufacturing the zoom optical system.SOLUTION: A zoom optical system provided herein comprises six or more lens groups consisting of a first lens group having positive refractive power and a rear group disposed on the image side of the first lens group, and is configured such that distances between the lens groups change while zooming, where the first lens group consists of two or less lenses. The six or more lens groups are configured so as to satisfy the following conditional expressions: 8.00<f1 / D1<27.00, 1.00<M1 / D1<12.00, where f1 represents a focal length of the first lens group, D1 represents an optical axial thickness of the first lens group, and M1 represents a displacement of the first lens group while zooming from the wide-angle end to the telephoto end.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a zoom optical system, an optical device, and a method for manufacturing a zoom optical system.

Background Art

[0002] Conventionally, zoom optical systems used in optical devices such as photographic cameras, digital still cameras, and video cameras have been proposed (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

[0004] The zoom optical system of the present disclosure has a plurality of lens groups of six or more groups. The plurality of lens groups includes a first lens group having a positive refractive power and a rear group disposed on the image side of the first lens group. During zooming, the distance between each lens group changes. The first lens group consists of two or fewer lenses and satisfies the following conditional expressions. 8.00 < f1 / D1 < 27.00 1.00 < M1 / D1 < 12.00 However, f1: Focal length of the first lens group D1: Thickness on the optical axis of the first lens group M1: Movement amount of the first lens group during zooming from the wide-angle end state to the telephoto end state

[0005] The method for manufacturing a zoom optical system of the present disclosure is a method for manufacturing a zoom optical system having a plurality of lens groups of six or more groups. The plurality of lens groups includes a first lens group having a positive refractive power and a rear group disposed on the image side of the first lens group. During zooming, the distance between each lens group changes. The first lens group consists of two or fewer lenses and is arranged so as to satisfy the following conditional expressions. 8.00 < f1 / D1 < 27.00 1.00 < M1 / D1 < 12.00 However, f1: Focal length of the first lens group D1: Thickness on the optical axis of the first lens group M1: Movement amount of the first lens group during zooming from the wide-angle end state to the telephoto end state

Brief Description of the Drawings

[0006]

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Embodiments for Carrying Out the Invention

[0007] Hereinafter, the zoom optical system, the optical apparatus, and the manufacturing method of the zoom optical system according to the embodiments of the present application will be described.

[0008] The zoom optical system of this embodiment has a plurality of lens groups of 6 groups or more. The plurality of lens groups consists of a first lens group having a positive refractive power and a rear group arranged on the image side with respect to the first lens group. During zooming, the interval between each lens group changes. The first lens group consists of 2 or fewer lenses and satisfies the following conditional expressions. (1) 8.00 < f1 / D1 < 27.00 (2) 1.00 < M1 / D1 < 12.00 However, f1: Focal length of the first lens group D1: Thickness on the optical axis of the first lens group M1: Movement amount of the first lens group during zooming from the wide-angle end state to the telephoto end state

[0009] By making the first lens group consist of 2 or fewer lenses, the zoom optical system of this embodiment can achieve a lightweight zoom optical system.

[0010] Conditional expression (1) defines the ratio of the focal length of the first lens group to the thickness on the optical axis of the first lens group. By satisfying conditional expression (1), the zoom optical system of the present embodiment can appropriately suppress fluctuations in various aberrations including spherical aberration during zooming.

[0011] In the zoom optical system of the present embodiment, when the value of conditional expression (1) exceeds the upper limit value, the thickness on the optical axis of the first lens group becomes too small, making it difficult to appropriately suppress fluctuations in various aberrations including spherical aberration during zooming.

[0012] In the zoom optical system of the present embodiment, by setting the upper limit value of conditional expression (1) to 27.00, the effects of the present embodiment can be made more certain. Further, in order to make the effects of the present embodiment more certain, it is preferable to set the upper limit value of conditional expression (1) to 26.50, 26.25, 26.10, 25.00, 22.50, 20.00, 17.50, 15.00, and further 14.00.

[0013] Also, in the zoom optical system of the present embodiment, when the value of conditional expression (1) is below the lower limit value, the refractive power of the first lens group becomes too strong, making it difficult to appropriately suppress fluctuations in various aberrations including spherical aberration during zooming.

[0014] In the zoom optical system of the present embodiment, by setting the lower limit value of conditional expression (1) to 8.00, the effects of the present embodiment can be made more certain. Further, in order to make the effects of the present embodiment more certain, it is preferable to set the lower limit value of conditional expression (1) to 8.20, 8.40, 8.50, 8.75, 9.00, 9.10, 9.20, and further 9.30.

[0015] Conditional expression (2) defines the ratio of the movement amount of the first lens group during zooming from the wide-angle end state to the telephoto end state to the thickness on the optical axis of the first lens group. By satisfying conditional expression (2), the zoom optical system of the present embodiment can appropriately suppress fluctuations in various aberrations including spherical aberration during zooming.

[0016] In the zoom optical system of this embodiment, if the value of conditional expression (2) exceeds the upper limit value, the thickness on the optical axis of the first lens group becomes too small, and it becomes difficult to appropriately suppress fluctuations in various aberrations including spherical aberration during zooming.

[0017] In the zoom optical system of this embodiment, by setting the upper limit value of conditional expression (2) to 12.00, the effects of this embodiment can be made more certain. Further, in order to make the effects of this embodiment more certain, it is preferable to set the upper limit value of conditional expression (2) to 11.75, 11.50, 11.25, 11.00, 10.90, 10.80, and further 10.70.

[0018] Also, in the zoom optical system of this embodiment, if the value of conditional expression (2) is less than the lower limit value, the movement amount of the first lens group becomes too large, and it becomes difficult to appropriately suppress fluctuations in various aberrations including spherical aberration during zooming.

[0019] In the zoom optical system of this embodiment, by setting the lower limit value of conditional expression (2) to 1.00, the effects of this embodiment can be made more certain. Further, in order to make the effects of this embodiment more certain, it is preferable to set the lower limit value of conditional expression (2) to 1.25, 1.50, 1.75, 2.00, 2.25, 2.50, and further 2.60.

[0020] In a zoom optical system that satisfies both conditional expression (1) and conditional expression (2), fluctuations in various aberrations including spherical aberration during zooming can be appropriately suppressed.

[0021] Also, in the zoom optical system of this embodiment, the rear group has a first negative lens group having a negative refractive power, and preferably satisfies the following conditional expression. (3) 1.00 < f1 / (-fN1) < 8.00 However, fN1: Focal length of the first negative lens group

[0022] Conditional expression (3) defines the ratio of the focal length of the first lens group to the focal length of the first negative lens group. By satisfying conditional expression (3), the varifocal optical system of the present embodiment can appropriately suppress fluctuations in various aberrations including spherical aberration during varifocal operation.

[0023] In the varifocal optical system of the present embodiment, when the value of conditional expression (3) exceeds the upper limit value, the refractive power of the first negative lens group becomes too strong, making it difficult to appropriately suppress fluctuations in various aberrations including spherical aberration during varifocal operation.

[0024] In the varifocal optical system of the present embodiment, by setting the upper limit value of conditional expression (3) to 8.00, the effects of the present embodiment can be made more reliable. Further, in order to make the effects of the present embodiment more reliable, it is preferable to set the upper limit value of conditional expression (3) to 7.75, 7.50, 7.25, 7.00, 6.85, 6.75, and further 6.65.

[0025] Also, in the varifocal optical system of the present embodiment, when the value of conditional expression (3) is below the lower limit value, the refractive power of the first lens group becomes too strong, making it difficult to appropriately suppress fluctuations in various aberrations including spherical aberration during varifocal operation.

[0026] In the varifocal optical system of the present embodiment, by setting the lower limit value of conditional expression (3) to 1.00, the effects of the present embodiment can be made more reliable. Further, in order to make the effects of the present embodiment more reliable, it is preferable to set the lower limit value of conditional expression (3) to 1.25, 1.50, 1.75, 2.00, 2.25, 2.50, 2.75, 3.00, 3.25, and further 3.50.

[0027] Also, in the varifocal optical system of the present embodiment, the rear group includes a first negative lens group having a negative refractive power and a second negative lens group having a negative refractive power disposed on the image side of the first negative lens group, and preferably satisfies the following formula. (4) 0.10 < f1 / (-fN2) < 5.00 However, fN2: Focal length of the second negative lens group

[0028] Conditional expression (4) defines the ratio of the focal length of the first lens group to the focal length of the second negative lens group. By satisfying conditional expression (4), the zoom optical system of the present embodiment can appropriately suppress fluctuations in various aberrations including spherical aberration during zooming.

[0029] In the zoom optical system of the present embodiment, when the value of conditional expression (4) exceeds the upper limit value, the refractive power of the second negative lens group becomes too strong, making it difficult to appropriately suppress fluctuations in various aberrations including spherical aberration during zooming.

[0030] In the zoom optical system of the present embodiment, by setting the upper limit value of conditional expression (4) to 5.00, the effects of the present embodiment can be made more certain. Further, in order to make the effects of the present embodiment more certain, it is preferable to set the upper limit value of conditional expression (4) to 4.85, 4.75, 4.60, 4.50, 4.25, and further 4.00.

[0031] Also, in the zoom optical system of the present embodiment, when the value of conditional expression (4) is below the lower limit value, the refractive power of the first lens group becomes too strong, making it difficult to appropriately suppress fluctuations in various aberrations including spherical aberration during zooming.

[0032] In the zoom optical system of the present embodiment, by setting the lower limit value of conditional expression (4) to 0.10, the effects of the present embodiment can be made more certain. Further, in order to make the effects of the present embodiment more certain, it is preferable to set the lower limit value of conditional expression (4) to 0.11, 0.12, 0.25, 0.30, 0.50, 0.75, 1.00, 1.25, 1.75, and further 2.00.

[0033] Also, in the zoom optical system of the present embodiment, the rear group has a first negative lens group having a negative refractive power and a second negative lens group having a negative refractive power disposed on the image side of the first negative lens group, and preferably satisfies the following formula. (5) 0.01 < fN1 / fN2 < 1.00 However, fN1: Focal length of the first negative lens group fN2: Focal length of the second negative lens group

[0034] The conditional expression (5) defines the ratio between the focal length of the first negative lens group and the focal length of the second negative lens group. By satisfying the conditional expression (5), the varifocal optical system of the present embodiment can appropriately suppress fluctuations in various aberrations including spherical aberration during varifocal operation.

[0035] When the value of the conditional expression (5) exceeds the upper limit value in the varifocal optical system of the present embodiment, the refractive power of the second negative lens group becomes too strong, making it difficult to appropriately suppress fluctuations in various aberrations including spherical aberration during varifocal operation.

[0036] In the varifocal optical system of the present embodiment, by setting the upper limit value of the conditional expression (5) to 1.00, the effects of the present embodiment can be made more certain. Further, in order to make the effects of the present embodiment more certain, it is preferable to set the upper limit value of the conditional expression (5) to 0.95, 0.90, 0.85, 0.80, 0.75, 0.70, and further 0.65.

[0037] Also, when the value of the conditional expression (5) is below the lower limit value in the varifocal optical system of the present embodiment, the refractive power of the first negative lens group becomes too strong, making it difficult to appropriately suppress fluctuations in various aberrations including spherical aberration during varifocal operation.

[0038] In the varifocal optical system of the present embodiment, by setting the lower limit value of the conditional expression (5) to 0.01, the effects of the present embodiment can be made more certain. Further, in order to make the effects of the present embodiment more certain, it is preferable to set the lower limit value of the conditional expression (5) to 0.02, 0.05, 0.10, 0.15, 0.20, 0.25, and further 0.30.

[0039] Also, in the varifocal optical system of the present embodiment, it is preferable that the first negative lens group is the lens group arranged closest to the object side among the lens groups having negative refractive power within the rear group.

[0040] By having such a configuration, the zoom optical system of the present embodiment can appropriately suppress fluctuations in various aberrations including spherical aberration during zooming.

[0041] Further, in the zoom optical system of the present embodiment, it is preferable that the rear group has a first positive lens group having a positive refractive power and satisfies the following conditional expression. (6) 0.75 < f1 / fP1 < 5.00 However, fP1: Focal length of the first positive lens group

[0042] Conditional expression (6) defines the ratio of the focal length of the first lens group to the focal length of the first positive lens group. By satisfying conditional expression (6), the zoom optical system of the present embodiment can appropriately suppress fluctuations in various aberrations including spherical aberration during zooming.

[0043] When the value of conditional expression (6) exceeds the upper limit value in the zoom optical system of the present embodiment, the refractive power of the first positive lens group becomes too strong, and it becomes difficult to appropriately suppress fluctuations in various aberrations including spherical aberration during zooming.

[0044] In the zoom optical system of the present embodiment, by setting the upper limit value of conditional expression (6) to 5.00, the effects of the present embodiment can be made more reliable. Further, in order to make the effects of the present embodiment more reliable, it is preferable to set the upper limit value of conditional expression (6) to 4.90, 4.80, 4.75, 4.70, 4.60, 4.50, and further 4.45.

[0045] Also, when the value of conditional expression (6) is below the lower limit value in the zoom optical system of the present embodiment, the refractive power of the first lens group becomes too strong, and it becomes difficult to appropriately suppress fluctuations in various aberrations including spherical aberration during zooming.

[0046] In the zoom optical system of the present embodiment, by setting the lower limit value of conditional expression (6) to 0.75, the effects of the present embodiment can be made more certain. Further, in order to make the effects of the present embodiment more certain, it is preferable to set the lower limit value of conditional expression (6) to 0.80, 0.85, 0.90, 0.95, 1.00, 1.05, 1.10, 1.15, and further 1.20.

[0047] In the zoom optical system of the present embodiment, the rear group has a first positive lens group having a positive refractive power and a first negative lens group having a negative refractive power disposed on the image side of the first positive lens group, and preferably satisfies the following conditional expression. (7) 0.75 < fP1 / (-fN1) < 4.50 However, fP1: Focal length of the first positive lens group fN1: Focal length of the first negative lens group

[0048] Conditional expression (7) defines the ratio of the focal length of the first positive lens group to the focal length of the first negative lens group. By satisfying conditional expression (7), the zoom optical system of the present embodiment can appropriately suppress fluctuations in various aberrations including spherical aberration during zooming.

[0049] When the value of conditional expression (7) exceeds the upper limit value in the zoom optical system of the present embodiment, the refractive power of the first negative lens group becomes too strong, and it becomes difficult to appropriately suppress fluctuations in various aberrations including spherical aberration during zooming.

[0050] In the zoom optical system of the present embodiment, by setting the upper limit value of conditional expression (7) to 4.50, the effects of the present embodiment can be made more certain. Further, in order to make the effects of the present embodiment more certain, it is preferable to set the upper limit value of conditional expression (7) to 4.35, 4.25, 4.10, 4.00, 3.90, and further 3.85.

[0051] In addition, in the zoom optical system of the present embodiment, when the value of conditional expression (7) is less than the lower limit value, the refractive power of the first positive lens group becomes too strong, and it becomes difficult to appropriately suppress fluctuations in various aberrations including spherical aberration during zooming.

[0052] In the zoom optical system of the present embodiment, by setting the lower limit value of conditional expression (7) to 0.75, the effects of the present embodiment can be made more certain. Further, in order to make the effects of the present embodiment more certain, it is preferable to set the lower limit value of conditional expression (7) to 0.85, 0.95, 1.00, 1.10, 1.20, 1.50, 1.70, and further 2.00.

[0053] In addition, in the zoom optical system of the present embodiment, the rear group includes a first positive lens group having a positive refractive power and a first negative lens group having a negative refractive power disposed on the image side of the first positive lens group, and it is preferable to satisfy the following conditional expression. (8) 1.00 < MP1 / MN1 < 20.00 However, MP1: Movement amount of the first positive lens group during zooming from the wide-angle end state to the telephoto end state MN1: Movement amount of the first negative lens group during zooming from the wide-angle end state to the telephoto end state

[0054] Conditional expression (8) defines the ratio of the movement amount of the first positive lens group during zooming to the movement amount of the first negative lens group during zooming. The zoom optical system of the present embodiment can appropriately suppress fluctuations in various aberrations including spherical aberration during zooming by satisfying conditional expression (8).

[0055] In the zoom optical system of the present embodiment, when the value of conditional expression (8) exceeds the upper limit value, the movement amount of the first negative lens group becomes too small, and it becomes difficult to appropriately suppress fluctuations in various aberrations including spherical aberration during zooming.

[0056] In the zoom optical system of the present embodiment, by setting the upper limit value of the conditional expression (8) to 20.00, the effects of the present embodiment can be made more certain. Further, in order to make the effects of the present embodiment more certain, it is preferable to set the upper limit value of the conditional expression (8) to 18.00, 15.00, 12.25, 10.00, 9.00, 7.50, 6.00, 5.50, 5.00, 4.50, 4.00, and further 3.50.

[0057] Further, in the zoom optical system of the present embodiment, when the value of the conditional expression (8) is less than the lower limit value, the moving amount of the first positive lens group becomes too small, and it becomes difficult to appropriately suppress fluctuations in various aberrations including spherical aberration during zooming.

[0058] In the zoom optical system of the present embodiment, by setting the lower limit value of the conditional expression (8) to 1.00, the effects of the present embodiment can be made more certain. Further, in order to make the effects of the present embodiment more certain, it is preferable to set the lower limit value of the conditional expression (8) to 1.10, 1.25, 1.40, 1.50, 1.60, 1.75, and further 1.90.

[0059] Further, in the zoom optical system of the present embodiment, it is preferable that the rear group includes a first positive lens group having a positive refractive power and a second positive lens group having a positive refractive power disposed on the image side of the first positive lens group.

[0060] By having such a configuration, the zoom optical system of the present embodiment can appropriately suppress fluctuations in various aberrations including spherical aberration during zooming.

[0061] Further, it is preferable that the zoom optical system of the present embodiment satisfies the following conditional expression. (9) 0.25 < fP1 / fP2 < 3.50 However, fP1: Focal length of the first positive lens group fP2: Focal length of the second positive lens group

[0062] The conditional expression (9) defines the ratio of the focal length of the first positive lens group to the focal length of the second positive lens group. By satisfying the conditional expression (9), the zoom optical system of the present embodiment can appropriately suppress fluctuations in various aberrations including spherical aberration during zooming.

[0063] In the zoom optical system of the present embodiment, when the value of the conditional expression (9) exceeds the upper limit value, the refractive power of the second positive lens group becomes too strong, and it becomes difficult to appropriately suppress fluctuations in various aberrations including spherical aberration during zooming.

[0064] In the zoom optical system of the present embodiment, by setting the upper limit value of the conditional expression (9) to 3.50, the effects of the present embodiment can be made more reliable. Further, in order to make the effects of the present embodiment more reliable, it is preferable to set the upper limit value of the conditional expression (9) to 3.45, 3.40, 3.35, 3.30, 3.25, and further 3.20.

[0065] Also, in the zoom optical system of the present embodiment, when the value of the conditional expression (9) is less than the lower limit value, the refractive power of the first positive lens group becomes too strong, and it becomes difficult to appropriately suppress fluctuations in various aberrations including spherical aberration during zooming.

[0066] In the zoom optical system of the present embodiment, by setting the lower limit value of the conditional expression (9) to 0.25, the effects of the present embodiment can be made more reliable. Further, in order to make the effects of the present embodiment more reliable, it is preferable to set the lower limit value of the conditional expression (9) to 0.28, 0.30, 0.35, 0.45, 0.50, 0.60, and further 0.75.

[0067] Also, in the zoom optical system of the present embodiment, it is preferable that the first positive lens group is the lens group arranged closest to the object side among the lens groups having positive refractive power within the rear group.

[0068] By having such a configuration, the zoom optical system of the present embodiment can appropriately suppress fluctuations in various aberrations including spherical aberration during zooming.

[0069] In addition, in the zoom optical system of the present embodiment, the rear group has a positive focusing group that has a positive refractive power and moves along the optical axis during focusing, and it is preferable to satisfy the following conditional expression. (10) 0.75 < f1 / fFP < 4.50 However, fFP: Focal length of the positive focusing group

[0070] The conditional expression (10) defines the ratio of the focal length of the first lens group to the focal length of the positive focusing group. By satisfying the conditional expression (10), the zoom optical system of the present embodiment can appropriately suppress fluctuations in various aberrations such as spherical aberration during focusing and zooming.

[0071] In the zoom optical system of the present embodiment, when the value of the conditional expression (10) exceeds the upper limit value, the refractive power of the positive focusing group becomes too strong, and it becomes difficult to appropriately suppress fluctuations in various aberrations such as spherical aberration during focusing.

[0072] In the zoom optical system of the present embodiment, by setting the upper limit value of the conditional expression (10) to 4.50, the effects of the present embodiment can be made more reliable. Further, in order to make the effects of the present embodiment more reliable, it is preferable to set the upper limit value of the conditional expression (10) to 4.25, 4.15, 4.00, 3.50, 3.25, 3.00, 2.75, 2.60, 2.25, and further 2.00.

[0073] In addition, in the zoom optical system of the present embodiment, when the value of the conditional expression (10) is below the lower limit value, the refractive power of the first lens group becomes too strong, and it becomes difficult to appropriately suppress fluctuations in various aberrations such as spherical aberration during zooming.

[0074] In the zoom optical system of the present embodiment, by setting the lower limit value of the conditional expression (10) to 0.75, the effects of the present embodiment can be made more reliable. Further, in order to make the effects of the present embodiment more reliable, it is preferable to set the lower limit value of the conditional expression (10) to 0.80, 0.90, 0.95, and further 1.00.

[0075] In addition, in the zoom optical system of the present embodiment, the rear group has a positive focusing group that has a positive refractive power and moves along the optical axis during focusing, and it is preferable to satisfy the following conditional expression. (11) -3.50 < fFP / fRPw < -0.50 However, fFP: Focal length of the positive focusing group fRPw: Composite focal length in the wide-angle end state of the lens group arranged on the image side with respect to the positive focusing group

[0076] The conditional expression (11) defines the ratio between the focal length of the positive focusing group and the composite focal length in the wide-angle end state of the lens group arranged on the image side with respect to the positive focusing group. By satisfying the conditional expression (11), the zoom optical system of the present embodiment can appropriately suppress various aberrations including coma aberration in the wide-angle end state, and can appropriately suppress fluctuations in various aberrations including spherical aberration during focusing.

[0077] When the value of the conditional expression (11) exceeds the upper limit value in the zoom optical system of the present embodiment, the refractive power in the wide-angle end state of the lens group arranged on the image side with respect to the positive focusing group becomes too strong, and it becomes difficult to appropriately suppress various aberrations including coma aberration in the wide-angle end state.

[0078] In the zoom optical system of the present embodiment, by setting the upper limit value of the conditional expression (11) to -0.50, the effects of the present embodiment can be made more certain. Further, in order to make the effects of the present embodiment more certain, it is preferable to set the upper limit value of the conditional expression (11) to -0.55, -0.60, -0.65, and further -0.70.

[0079] In addition, when the value of the conditional expression (11) is lower than the lower limit value in the zoom optical system of the present embodiment, the refractive power of the positive focusing group becomes too strong, and it becomes difficult to appropriately suppress fluctuations in various aberrations including spherical aberration during focusing.

[0080] In the zoom optical system of the present embodiment, by setting the lower limit value of the conditional expression (11) to -3.50, the effects of the present embodiment can be made more certain. Further, in order to make the effects of the present embodiment more certain, it is preferable to set the lower limit value of the conditional expression (11) to -3.40, -3.30, -3.25, -3.20, and further -3.15.

[0081] Further, in the zoom optical system of the present embodiment, the rear group has a negative focusing group that has a negative refractive power and moves along the optical axis during focusing, and it is preferable to satisfy the following conditional expression. (12) 0.10 < f1 / (-fFN) < 4.00 However, fFN: Focal length of the negative focusing group

[0082] The conditional expression (12) defines the ratio of the focal length of the first lens group to the focal length of the negative focusing group. By satisfying the conditional expression (12), the zoom optical system of the present embodiment can appropriately suppress fluctuations in various aberrations such as spherical aberration during focusing and zooming.

[0083] When the value of the conditional expression (12) exceeds the upper limit value in the zoom optical system of the present embodiment, the refractive power of the negative focusing group becomes too strong, and it becomes difficult to appropriately suppress fluctuations in various aberrations such as spherical aberration during focusing.

[0084] In the zoom optical system of the present embodiment, by setting the upper limit value of the conditional expression (12) to 4.00, the effects of the present embodiment can be made more certain. Further, in order to make the effects of the present embodiment more certain, it is preferable to set the upper limit value of the conditional expression (12) to 3.90, 3.80, 3.55, 3.25, and further 3.00.

[0085] Further, when the value of the conditional expression (12) is below the lower limit value in the zoom optical system of the present embodiment, the refractive power of the first lens group becomes too strong, and it becomes difficult to appropriately suppress fluctuations in various aberrations such as spherical aberration during zooming.

[0086] In the zoom optical system of this embodiment, by setting the lower limit value of conditional expression (12) to 0.10, the effects of this embodiment can be made more certain. Further, in order to make the effects of this embodiment more certain, it is preferable to set the lower limit value of conditional expression (12) to 0.12, 0.25, 0.50, 0.75, 1.00, and further 1.25.

[0087] Further, in the zoom optical system of this embodiment, the rear group has a negative focusing group that has a negative refractive power and moves along the optical axis during focusing, and it is preferable to satisfy the following conditional expression. (13) -25.00 < (-fFN) / fRNw < 1.00 However, fFN: Focal length of the negative focusing group fRNw: Composite focal length in the wide-angle end state of the lens group arranged on the image side of the negative focusing group

[0088] Conditional expression (13) defines the ratio of the focal length of the negative focusing group to the focal length in the wide-angle end state of the lens group arranged on the image side of the negative focusing group. By satisfying conditional expression (13), the zoom optical system of this embodiment can appropriately suppress various aberrations including coma aberration in the wide-angle end state, and can appropriately suppress fluctuations in various aberrations including spherical aberration during focusing.

[0089] When the value of conditional expression (13) exceeds the upper limit value in the zoom optical system of this embodiment, the refractive power in the wide-angle end state of the lens group arranged on the image side of the negative focusing group becomes too strong, and it becomes difficult to appropriately suppress various aberrations including coma aberration in the wide-angle end state.

[0090] In the zoom optical system of this embodiment, by setting the upper limit value of conditional expression (13) to 1.00, the effects of this embodiment can be made more certain. Further, in order to make the effects of this embodiment more certain, it is preferable to set the upper limit value of conditional expression (13) to 0.90, 0.80, 0.75, 0.70, 0.65, 0.60, 0.55, and further 0.50.

[0091] In addition, in the zoom optical system of the present embodiment, when the value of conditional expression (13) is less than the lower limit value, the refractive power of the negative defocus group becomes too strong, and it becomes difficult to appropriately suppress fluctuations in various aberrations including spherical aberration during focusing.

[0092] In the zoom optical system of the present embodiment, by setting the lower limit value of conditional expression (13) to -25.00, the effects of the present embodiment can be made more certain. Further, in order to make the effects of the present embodiment more certain, it is preferable to set the lower limit value of conditional expression (13) to -24.00, -20.00, -17.50, -15.00, -12.25, -10.00, -7.50, -5.00, -2.50, and further -1.50.

[0093] In addition, in the zoom optical system of the present embodiment, the final lens group arranged closest to the image side among the lens groups in the rear group has a negative refractive power, and it is preferable to satisfy the following conditional expression. (14) 0.10 < f1 / (-fR) < 5.00 However, fR: Focal length of the final lens group

[0094] Conditional expression (14) defines the ratio of the focal length of the first lens group to the focal length of the final lens group. By satisfying conditional expression (14), the zoom optical system of the present embodiment can appropriately suppress fluctuations in various aberrations including spherical aberration during zooming.

[0095] In the zoom optical system of the present embodiment, when the value of conditional expression (14) exceeds the upper limit value, the refractive power of the final lens group becomes too strong, and it becomes difficult to appropriately suppress fluctuations in various aberrations including coma aberration during zooming.

[0096] In the zoom optical system of the present embodiment, by setting the upper limit value of conditional expression (14) to 5.00, the effects of the present embodiment can be made more certain. Further, in order to make the effects of the present embodiment more certain, it is preferable to set the upper limit value of conditional expression (14) to 4.95, 4.90, 4.85, 4.50, 4.25, 4.00, and further 3.75.

[0097] Further, in the zoom optical system of the present embodiment, when the value of conditional expression (14) is lower than the lower limit value, the refractive power of the first lens group becomes too strong, and it becomes difficult to appropriately suppress fluctuations in various aberrations including spherical aberration during zooming.

[0098] In the zoom optical system of the present embodiment, by setting the lower limit value of conditional expression (14) to 0.10, the effects of the present embodiment can be made more certain. Further, in order to make the effects of the present embodiment more certain, it is preferable to set the lower limit value of conditional expression (14) to 0.25, 0.40, 0.50, 0.60, 0.70, and further 0.75.

[0099] Further, in the zoom optical system of the present embodiment, among the lens groups in the rear group, the final lens group arranged closest to the image side has a positive refractive power and preferably satisfies the following conditional expression. (15) 0.10 < f1 / fR < 1.50 However, fR: Focal length of the final lens group

[0100] Conditional expression (15) defines the ratio of the focal length of the first lens group to the focal length of the final lens group. By satisfying conditional expression (15), the zoom optical system of the present embodiment can appropriately suppress fluctuations in various aberrations including spherical aberration during zooming.

[0101] In the zoom optical system of the present embodiment, when the value of conditional expression (15) exceeds the upper limit value, the refractive power of the final lens group becomes too strong, and it becomes difficult to appropriately suppress fluctuations in various aberrations including coma aberration during zooming.

[0102] In the zoom optical system of the present embodiment, by setting the upper limit value of conditional expression (15) to 1.50, the effects of the present embodiment can be made more certain. Further, in order to make the effects of the present embodiment more certain, it is preferable to set the upper limit value of conditional expression (15) to 1.40, 1.30, 1.25, 1.20, 1.15, 1.10, and further 1.05.

[0103] In addition, in the zoom optical system of the present embodiment, when the value of conditional expression (15) is lower than the lower limit value, the refractive power of the first lens group becomes too strong, and it becomes difficult to appropriately suppress fluctuations in various aberrations including spherical aberration during zooming.

[0104] In the zoom optical system of the present embodiment, by setting the lower limit value of conditional expression (15) to 0.10, the effects of the present embodiment can be made more reliable. Further, in order to make the effects of the present embodiment more reliable, it is preferable to set the lower limit value of conditional expression (15) to 0.15, 0.20, 0.25, 0.30, and further 0.35.

[0105] In addition, in the zoom optical system of the present embodiment, the first lens group preferably has at least one lens that satisfies both of the following conditional expressions. (16) 1.45 < nd1 < 2.10 (17) 20.00 < νd1 < 75.00 However, nd1: Refractive index of the lens in the first lens group with respect to the d-line νd1: Abbe number of the lens in the first lens group based on the d-line

[0106] Conditional expression (16) defines the refractive index of the lens in the first lens group with respect to the d-line, and conditional expression (17) defines the Abbe number of the lens in the first lens group based on the d-line. The zoom optical system of the present embodiment can favorably correct various aberrations including spherical aberration and chromatic aberration in the telephoto state by having at least one lens in the first lens group that satisfies both conditional expression (16) and conditional expression (17).

[0107] In the zoom optical system of the present embodiment, when the value of conditional expression (16) exceeds the upper limit value, the refractive power of the final lens group becomes too strong, and it becomes difficult to appropriately suppress fluctuations in various aberrations including coma aberration during zooming.

[0108] In the zoom optical system of this embodiment, by setting the upper limit value of conditional expression (16) to 2.10, the effects of this embodiment can be made more certain. Further, in order to make the effects of this embodiment more certain, it is preferable to set the upper limit value of conditional expression (16) to 2.05, 2.00, and further 1.98.

[0109] Also, in the zoom optical system of this embodiment, when the value of conditional expression (16) is below the lower limit value, the refractive power of the lenses in the first lens group becomes too weak, and it becomes difficult to correct various aberrations such as spherical aberration in the telephoto end state well.

[0110] In the zoom optical system of this embodiment, by setting the lower limit value of conditional expression (16) to 1.45, the effects of this embodiment can be made more certain. Further, in order to make the effects of this embodiment more certain, it is preferable to set the lower limit value of conditional expression (16) to 1.48, 1.50, 1.53, 1.55, and further 1.57.

[0111] In the zoom optical system of this embodiment, when the value of conditional expression (17) exceeds the upper limit value, the dispersion of the lenses in the first lens group becomes too small, and it becomes difficult to correct chromatic aberration in the telephoto end state well.

[0112] In the zoom optical system of this embodiment, by setting the upper limit value of conditional expression (17) to 75.00, the effects of this embodiment can be made more certain. Further, in order to make the effects of this embodiment more certain, it is preferable to set the upper limit value of conditional expression (17) to 74.00, 72.50, 71.00, 70.00, and further 68.50.

[0113] Also, in the zoom optical system of this embodiment, when the value of conditional expression (17) is below the lower limit value, the dispersion of the lenses in the first lens group becomes too small, and it becomes difficult to correct chromatic aberration in the telephoto end state well.

[0114] In the zoom optical system of this embodiment, by setting the lower limit value of conditional expression (17) to 20.00, the effects of this embodiment can be made more certain. Further, in order to make the effects of this embodiment more certain, it is preferable to set the lower limit value of conditional expression (17) to 21.00, 22.50, and further 23.00.

[0115] Further, in the zoom optical system of this embodiment, it is preferable that the lens arranged closest to the image side satisfies the following conditional expression. (18) -12.00 < (r2 - r1) / (r2 + r1) < 2.00 However, r1: The radius of curvature of the object-side lens surface of the lens arranged closest to the image side r1: The radius of curvature of the image-side lens surface of the lens arranged closest to the image side

[0116] Conditional expression (18) defines the shape factor of the lens arranged closest to the image side. By satisfying conditional expression (18), the zoom optical system of this embodiment can appropriately suppress fluctuations in various aberrations including coma aberration during zooming.

[0117] When the value of conditional expression (18) exceeds the upper limit value in the zoom optical system of this embodiment, the coma aberration cannot be appropriately corrected by the lens arranged closest to the image side, and it becomes difficult to appropriately suppress fluctuations in various aberrations including coma aberration during zooming.

[0118] In the zoom optical system of this embodiment, by setting the upper limit value of conditional expression (18) to 2.00, the effects of this embodiment can be made more certain. Further, in order to make the effects of this embodiment more certain, it is preferable to set the upper limit value of conditional expression (18) to 1.90, 1.80, and further 1.75.

[0119] Also, when the value of conditional expression (18) is below the lower limit value in the zoom optical system of this embodiment, the coma aberration cannot be appropriately corrected by the lens arranged closest to the image side, and it becomes difficult to appropriately suppress fluctuations in various aberrations including coma aberration during zooming.

[0120] In the zoom optical system of this embodiment, by setting the lower limit value of conditional expression (18) to -12.00, the effects of this embodiment can be made more certain. Further, in order to make the effects of this embodiment more certain, it is preferable to set the lower limit value of conditional expression (18) to -11.75, -11.50, -11.25, -10.00, -7.50, -5.00, and further to -3.00.

[0121] Further, in the zoom optical system of this embodiment, the rear group has a negative focusing group that has a negative refractive power and moves along the optical axis during focusing, and it is preferable to satisfy the following conditional expression. (19) 0.75 < fN / fFN < 30.00 However, fN: The focal length of the lens group with the weakest refractive power among the lens groups having a negative refractive power within the rear group fFN: The focal length of the negative focusing group

[0122] Conditional expression (19) defines the ratio of the focal length of the lens group with the weakest refractive power among the lens groups having a negative refractive power within the rear group to the focal length of the negative focusing group. By satisfying conditional expression (19), the zoom optical system of this embodiment can appropriately suppress fluctuations in various aberrations including spherical aberration during focusing and zooming.

[0123] When the value of conditional expression (19) exceeds the upper limit value in the zoom optical system of this embodiment, the refractive power of the negative focusing group becomes too strong, and it becomes difficult to appropriately suppress fluctuations in various aberrations including spherical aberration during focusing.

[0124] In the zoom optical system of this embodiment, by setting the upper limit value of conditional expression (19) to 30.00, the effects of this embodiment can be made more certain. Further, in order to make the effects of this embodiment more certain, it is preferable to set the upper limit value of conditional expression (19) to 28.00, 27.00, 25.00, 20.00, 17.50, 15.00, 12.25, 10.00, 7.50, 5.00, and further to 3.50.

[0125] In addition, in the zoom optical system of the present embodiment, when the value of conditional expression (19) is lower than the lower limit value, the refractive power of the lens group with the weakest refractive power among the lens groups having negative refractive power in the rear group becomes too strong, and it becomes difficult to appropriately suppress fluctuations in various aberrations including spherical aberration during zooming.

[0126] In the zoom optical system of the present embodiment, by setting the lower limit value of conditional expression (19) to 0.75, the effects of the present embodiment can be made more certain. Further, in order to make the effects of the present embodiment more certain, it is preferable to set the lower limit value of conditional expression (19) to 0.80, 0.85, 0.90, and further 0.95.

[0127] In addition, the zoom optical system of the present embodiment preferably satisfies the following conditional expression. (20) Fnot < 7.00 However, Fnot: F-number of the zoom optical system in the telephoto end state

[0128] Conditional expression (20) defines the F-number of the zoom optical system in the telephoto end state. By satisfying conditional expression (20), the zoom optical system of the present embodiment can increase the amount of light it captures.

[0129] In the zoom optical system of the present embodiment, by setting the upper limit value of conditional expression (20) to 7.00, the effects of the present embodiment can be made more certain. Further, in order to make the effects of the present embodiment more certain, it is preferable to set the upper limit value of conditional expression (20) to 6.90, 6.80, 6.70, 6.60, 6.00, 5.00, and further 4.50.

[0130] In addition, in the zoom optical system of the present embodiment, among the lens groups in the rear group, the lens group arranged second from the image side is preferably moved along the optical axis during focusing.

[0131] In the zoom optical system of the present embodiment, by having such a configuration, fluctuations in various aberrations including spherical aberration during focusing can be appropriately suppressed.

[0132] In addition, the zoom optical system of this embodiment preferably satisfies the following conditional expression. (21) 0.10 < Bfw / fw < 0.95 However, Bfw: Back focus in the wide-angle end state of the zoom optical system fw: Focal length in the wide-angle end state of the zoom optical system

[0133] The conditional expression (21) defines the ratio of the back focus in the wide-angle end state of the zoom optical system to the focal length in the wide-angle end state of the zoom optical system. By satisfying the conditional expression (21), the zoom optical system of this embodiment can satisfactorily correct various aberrations including coma aberration in the wide-angle end state while avoiding an increase in the size of the optical system.

[0134] If the value of the conditional expression (21) exceeds the upper limit value in the zoom optical system of this embodiment, the back focus becomes too long, making it difficult to avoid an increase in the size of the optical system.

[0135] In the zoom optical system of this embodiment, by setting the upper limit value of the conditional expression (21) to 0.95, the effects of this embodiment can be made more certain. Further, in order to make the effects of this embodiment more certain, it is preferable to set the upper limit value of the conditional expression (21) to 0.90, 0.85, 0.80, and further 0.75.

[0136] Also, if the value of the conditional expression (21) is less than the lower limit value in the zoom optical system of this embodiment, the position of the exit pupil approaches the image plane too much, making it difficult to satisfactorily correct various aberrations including coma aberration in the wide-angle end state.

[0137] In the zoom optical system of this embodiment, by setting the lower limit value of the conditional expression (21) to 0.10, the effects of this embodiment can be made more certain. Further, in order to make the effects of this embodiment more certain, it is preferable to set the lower limit value of the conditional expression (21) to 0.15, 0.20, 0.25, 0.30, 0.35, and further 0.40.

[0138] In addition, in the zoom optical system of this embodiment, when zooming from the wide-angle end state to the telephoto end state, it is preferable that the first lens group moves toward the object side.

[0139] In the zoom optical system of this embodiment, by having such a configuration, while miniaturizing the zoom optical system, it is possible to appropriately suppress fluctuations in various aberrations including spherical aberration during zooming.

[0140] In addition, in the zoom optical system of this embodiment, it is preferable that the first lens group is composed of a negative lens and a positive lens in order from the object side.

[0141] In the zoom optical system of this embodiment, by having such a configuration, while reducing the weight of the zoom optical system, it is possible to favorably correct various aberrations including spherical aberration in the telephoto end state.

[0142] In addition, in the zoom optical system of this embodiment, it is preferable that the first lens group is composed of positive lenses.

[0143] In the zoom optical system of this embodiment, by having such a configuration, while reducing the weight of the zoom optical system, it is possible to favorably correct various aberrations including spherical aberration in the telephoto end state.

[0144] In addition, in the zoom optical system of this embodiment, it is preferable that the rear group has a first focusing group and a second focusing group that move along the optical axis during focusing, respectively.

[0145] In the zoom optical system of this embodiment, by having such a configuration, it is possible to appropriately suppress fluctuations in various aberrations including spherical aberration during focusing.

[0146] In addition, it is preferable that the zoom optical system of this embodiment satisfies the following conditional expression. (22) 0.20 < |fF1| / |fF2| < 30.00 However, fF1: Focal length of the first focusing group fF2: Focal length of the second focusing group

[0147] Conditional expression (22) defines the ratio between the focal length of the first focusing group and the focal length of the second focusing group. By satisfying conditional expression (22), the zoom optical system of this embodiment can appropriately suppress fluctuations in various aberrations including spherical aberration during focusing.

[0148] In the zoom optical system of this embodiment, when the value of conditional expression (22) exceeds the upper limit value, the refractive power of the second focusing group becomes too strong, making it difficult to appropriately suppress fluctuations in various aberrations including spherical aberration during focusing.

[0149] In the zoom optical system of this embodiment, by setting the upper limit value of conditional expression (22) to 30.00, the effects of this embodiment can be made more certain. Further, in order to make the effects of this embodiment more certain, it is preferable to set the upper limit value of conditional expression (22) to 27.00, 25.00, 10.00, 2.00, 1.95, 1.90, 1.85, 1.80, and further 1.75.

[0150] Also, in the zoom optical system of this embodiment, when the value of conditional expression (22) is below the lower limit value, the refractive power of the first focusing group becomes too strong, making it difficult to appropriately suppress fluctuations in various aberrations including spherical aberration during zooming.

[0151] In the zoom optical system of this embodiment, by setting the lower limit value of conditional expression (22) to 0.20, the effects of this embodiment can be made more certain. Further, in order to make the effects of this embodiment more certain, it is preferable to set the lower limit value of conditional expression (22) to 0.25, 0.30, 0.35, 0.40, 0.45, and further 0.50.

[0152] Also, in the zoom optical system of this embodiment, it is preferable that at least one of the positive lenses in the rear group satisfies the following first dispersion conditional expression. (23) νdP1 < 45.00 However, νdP1: Abbe number based on the d-line of the positive lens in the rear group

[0153] The first dispersion conditional expression (23) defines the Abbe number based on the d-line of the positive lens in the rear group. The variable magnification optical system of the present embodiment can correct chromatic aberration well by having a positive lens that satisfies the first dispersion conditional expression (23) in the rear group.

[0154] In the variable magnification optical system of the present embodiment, by setting the upper limit value of the first dispersion conditional expression (23) to 45.00, the effects of the present embodiment can be made more certain. Also, in order to make the effects of the present embodiment more certain, it is preferable to set the upper limit value of the first dispersion conditional expression (23) to 43.00, 40.00, 35.00, 30.00, and further 28.50.

[0155] Also, in the variable magnification optical system of the present embodiment, the positive lens that satisfies the first dispersion conditional expression (23) is preferably included in the negative lens group having a negative refractive power among the lens groups in the rear group.

[0156] In the variable magnification optical system of the present embodiment, by having such a configuration, chromatic aberration can be corrected better.

[0157] Also, in the variable magnification optical system of the present embodiment, at least one of the negative lenses in the rear group preferably satisfies the following second dispersion conditional expression. (24) 60.00 < νdN However, νdN: Abbe number based on the d-line of the negative lens in the rear group

[0158] The second dispersion conditional expression (24) defines the Abbe number based on the d-line of the negative lens in the rear group. The variable magnification optical system of the present embodiment can correct chromatic aberration well by having a negative lens that satisfies the second dispersion conditional expression (24).

[0159] In the zoom optical system of this embodiment, by setting the lower limit value of the second dispersion conditional expression (24) to 60.00, the effects of this embodiment can be made more certain. Further, in order to make the effects of this embodiment more certain, it is preferable to set the lower limit value of the second dispersion conditional expression (24) to 62.50, 65.00, 67.50, and further 75.00.

[0160] Further, in the zoom optical system of this embodiment, the negative lens that satisfies the second dispersion conditional expression (24) is preferably included in the final lens group disposed on the most image side among the lens groups in the rear group.

[0161] In the zoom optical system of this embodiment, by having such a configuration, chromatic aberration can be corrected better.

[0162] Further, in the zoom optical system of this embodiment, at least one of the lens groups having positive refractive power among the lens groups in the rear group preferably has a positive lens that satisfies the following third dispersion conditional expression. (25) 60.00 < νdP2 However, νdP2: Abbe number based on the d-line of the positive lens in the rear group

[0163] The third dispersion conditional expression (25) defines the Abbe number based on the d-line of the positive lens in the rear group. In the zoom optical system of this embodiment, since the lens group having positive refractive power has a positive lens that satisfies the third dispersion conditional expression (25), chromatic aberration can be corrected well.

[0164] In the zoom optical system of this embodiment, by setting the lower limit value of the third dispersion conditional expression (25) to 60.00, the effects of this embodiment can be made more certain. Further, in order to make the effects of this embodiment more certain, it is preferable to set the lower limit value of the third dispersion conditional expression (25) to 62.50, 65.00, 67.50, and further 75.00.

[0165] With the above configuration, a zoom optical system that is small-sized and has good imaging performance can be realized.

[0166] The optical device of this embodiment has a zoom optical system with the above-described configuration. As a result, an optical device having good optical performance can be realized.

[0167] The manufacturing method of the zoom optical system of this embodiment has a plurality of lens groups of six or more groups. The plurality of lens groups include a first lens group having a positive refractive power and a rear group disposed on the image side with respect to the first lens group. The manufacturing method of the zoom optical system is such that, during zooming, the interval between each lens group changes, the first lens group consists of two or fewer lenses, and they are arranged so as to satisfy all of the following conditional expressions. (1) 8.00 < f1 / D1 < 27.00 (2) 1.00 < M1 / D1 < 12.00 However, f1: Focal length of the first lens group D1: Thickness on the optical axis of the first lens group M1: Movement amount of the first lens group during zooming from the wide-angle end state to the telephoto end state

[0168] By such a manufacturing method of the zoom optical system, a zoom optical system having good optical performance can be manufactured.

[0169] (Numerical Example) Hereinafter, examples of the present application will be described with reference to the drawings.

[0170] (First Example) FIG. 1 is a cross-sectional view of the zoom optical system of the first example when focusing on an infinite object in the wide-angle end state.

[0171] The zoom optical system of this example includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, an aperture stop S, a third lens group G3 having a positive refractive power, a fourth lens group G4 having a positive refractive power, a fifth lens group G5 having a positive refractive power, a sixth lens group G6 having a positive refractive power, and a seventh lens group G7 having a negative refractive power.

[0172] The first lens group G1 consists of a cemented positive lens formed by, in order from the object side, a negative meniscus lens L1 with its convex surface facing the object side and a positive meniscus lens L2 with its convex surface facing the object side.

[0173] The second lens group G2 consists of, in order from the object side, a negative meniscus lens L3 with its convex surface facing the object side, a biconcave negative lens L4, a biconvex positive lens L5, and a negative meniscus lens L6 with its concave surface facing the object side.

[0174] The third lens group G3 consists of a positive meniscus lens L7 with its convex surface facing the object side and a biconvex positive lens L8.

[0175] The fourth lens group G4 consists of a cemented positive lens formed by, in order from the object side, a negative meniscus lens L9 with its convex surface facing the object side and a biconvex positive lens L10.

[0176] The fifth lens group G5 consists of, in order from the object side, a negative meniscus lens L11 with its concave surface facing the object side and a biconvex positive lens L12.

[0177] The sixth lens group G6 consists of a positive meniscus lens L13 with its concave surface facing the object side.

[0178] The seventh lens group G7 consists of, in order from the object side, a positive meniscus lens L14 with its concave surface facing the object side, a biconcave negative lens L15, and a negative meniscus lens L16 with its concave surface facing the object side.

[0179] An imaging device (not shown) composed of a CCD, a CMOS, or the like is disposed on the image plane I.

[0180] The zoom optical system of this embodiment performs focusing by moving the fifth lens group G5 and the sixth lens group G6 along the optical axis. When focusing from an infinitely focused state to a nearby object, the fifth lens group G5 and the sixth lens group G6 are each moved from the image side toward the object side.

[0181] In the zoom optical system of this embodiment, the second lens group G2, the third lens group G3, the fourth lens group G4, the fifth lens group G5, the sixth lens group G6, and the seventh lens group G7 belong to the rear group, and the seventh lens group G7 belongs to the final lens group. Also, the second lens group G2 belongs to the first negative lens group, the third lens group G3 belongs to the first positive lens group, the fourth lens group G4 belongs to the second positive lens group, and the seventh lens group G7 belongs to the second negative lens group. Further, the fifth lens group G5 belongs to the first focusing group, the sixth lens group G6 belongs to the second focusing group, and the fifth lens group G5 and the sixth lens group G6 belong to the positive focusing group.

[0182] The following Table 1 lists the values of the specifications of the zoom optical system of this embodiment.

[0183] In Table 1, fw is the focal length of the wide-angle end state of the zoom optical system, ft is the focal length of the telephoto end state of the zoom optical system, Fnow is the F-number of the wide-angle end state of the zoom optical system, and Fnot indicates the F-number of the wide-angle end state of the zoom optical system. Also, TL is the overall optical length of the zoom optical system when focusing on an infinite object in the wide-angle end state, and Bf indicates the back focus of the zoom optical system.

[0184] In Table 1, m is the order of the optical surface counted from the object side, r is the radius of curvature, d is the surface interval, nd is the refractive index with respect to the d-line (wavelength 587.6 nm), and νd indicates the Abbe number with respect to the d-line. The radius of curvature r = ∞ indicates a plane. Also, in [Lens Specifications], the optical surface marked with "*" indicates an aspherical surface. Also, in [Lens Specifications], the lenses corresponding to the positive lens P1 in conditional expression (23), the negative lens N in conditional expression (24), and the positive lens P2 in conditional expression (25) are shown respectively.

[0185] In Table 1, m is the optical surface corresponding to the aspherical data, K is the conic constant, and A4 to A14 indicate the aspherical coefficients.

[0186] For the aspherical surface, with the height in the direction perpendicular to the optical axis being y, the distance along the optical axis from the tangent plane at the vertex of each aspherical surface to the aspherical surface at height y (sag amount) being S(y), the radius of curvature of the reference spherical surface (paraxial radius of curvature) being r, the conic constant being K, and the aspherical coefficient of the nth order being An, it is expressed by the following formula (a). In each embodiment, the aspherical coefficient A2 of the second order is 0. Also, "E-n" means "×10 -n ".

[0187] (a) S(y) = (y 2 / r) / { 1 + (1 - K×y 2 / r 2 ) 1 / 2} + A4×y 4 + A6×y 6 + A8×y 8 + A10×y 10 + A12×y 12 + A14×y 14

[0188] The units of the focal lengths fw, ft, the radius of curvature r, and other lengths described in Table 1 are "mm". However, since the same optical performance can be obtained even if the zoom optical system is proportionally enlarged or reduced, it is not limited to this.

[0189] The symbols in Table 1 described above are used in the same way in the tables of other embodiments described later.

[0190] (Table 1) [Overall specifications] fw 24.75 ft 67.90 Fnow 2.92 Fnot 2.92 [Lens specifications] m r d nd νd (23) (24) (25) 1) 63.844 2.500 1.854505 25.15 2) 43.986 8.128 1.816000 46.59 3) 142.193 d3 * 4) 296.632 2.000 1.743890 49.53 5) 19.447 9.683 6) -100.452 1.300 1.834810 42.73 P1 7) 55.939 0.394 8) 38.386 6.222 1.728250 28.38 9) -56.749 2.082 10) -28.124 1.300 1.593490 67.00 N 11) -72.000 d11 12> ∞ 2.257 (Open aperture) *13) 45.234 2.437 1.820980 42.50 P1 14) 60.836 0.297 15) 39.871 5.325 1.593190 67.90 P2 16) -156.624 d16 17) 58.428 1.300 1.737999 32.33 18) 19.539 9.700 1.497820 82.57 P2 19) -57.826 d19 20) -24.303 1.200 1.720467 34.71 21) -64.092 0.200 22) 86.286 6.081 1.593490 67.00 P2 23) -33.001 d23 24) -72.398 2.669 1.791890 45.04 *25) -38.022 d25 26) -44.000 3.018 1.945944 17.98 27) -32.214 0.200 *28) -84.205 1.500 1.816000 46.59 29) 107.497 7.335 30) -26.834 1.400 1.592700 35.27 31) -54.107 Bf [Aspherical data] m K A4 A6 A8 A10 A12 4) 0.0000 5.67E-06 -6.48E-09 1.59E-11 -2.46E-14 1.99E-17 13) 0.0000 -3.46E-06 2.89E-09 -1.52E-11 2.39E-14 25) 0.0000 1.23E-05 -1.23E-08 2.75E-11 3.33E-14 -1.60E-16 28) 0.0000 -2.18E-06 -1.57E-08 -1.32E-11 1.50E-14 [Focal length data for each group] Group Starting surface Focal length G1 1 138.68 G2 4 -24.42 G3 13 43.63 G4 17 111.65 G5 20 124.10 G6 24 97.77 G7 26 -47.85 [Variable interval data] Wide-angle end state Telephoto end state d3 1.800 32.239 d11 22.304 2.000 d16 8.637 1.500 d19 5.489 19.095 d23 3.541 2.935 d25 5.473 2.073 Bf 11.855 28.555

[0191] FIG. 2A is a diagram of various aberrations when focusing on an infinite object in the wide-angle end state of the zoom optical system of the first embodiment, FIG. 2B is a diagram of various aberrations when focusing on an infinite object in the intermediate focal length state of the zoom optical system of the first embodiment, and FIG. 2C is a diagram of various aberrations when focusing on an infinite object in the telephoto end state of the zoom optical system of the first embodiment.

[0192] In each aberration diagram, FNO indicates the F-number and Y indicates the image height. Specifically, in the spherical aberration diagram, the value of the F-number corresponding to the maximum aperture is shown, in the astigmatism diagram and the distortion aberration diagram, the maximum value of the image height is shown, and in the coma aberration diagram, the value of each image height is shown. d indicates the d-line and g indicates the g-line (wavelength 435.8 nm). In the astigmatism diagram, the solid line indicates the sagittal image plane and the dashed line indicates the meridional image plane. The same reference signs as those in the aberration diagrams of the present embodiment are used in the aberration diagrams of other embodiments to be described later.

[0193] From each aberration diagram, it can be seen that the zoom optical system of the present embodiment effectively suppresses aberration variations during focusing and zooming and has high optical performance.

[0194] (Second Embodiment) FIG. 3 is a cross-sectional view of the zoom optical system of the second embodiment when focusing on an infinite object in the wide-angle end state.

[0195] The zoom optical system of the present embodiment includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, an aperture stop S, a third lens group G3 having a positive refractive power, a fourth lens group G4 having a positive refractive power, a fifth lens group G5 having a negative refractive power, and a sixth lens group G6 having a negative refractive power.

[0196] The first lens group G1 includes, in order from the object side, a cemented positive lens composed of a negative meniscus lens L1 with a convex surface facing the object side and a positive meniscus lens L2 with a convex surface facing the object side.

[0197] The second lens group G2 includes, in order from the object side, a negative meniscus lens L3 with a convex surface facing the object side, a biconcave negative lens L4, and a biconvex positive lens L5.

[0198] The third lens group G3 consists of a cemented positive lens formed by, in order from the object side, a positive meniscus lens L6 with its convex surface facing the object side, a negative meniscus lens L7 with its convex surface facing the object side, and a biconvex positive lens L8, and a cemented negative lens formed by a biconcave negative lens L9 and a biconvex positive lens L10.

[0199] The fourth lens group G4 consists of, in order from the object side, a negative meniscus lens L11 with its concave surface facing the object side and a biconvex positive lens L12.

[0200] The fifth lens group G5 consists of a biconcave negative lens L13.

[0201] The sixth lens group G6 consists of a biconcave negative lens L14.

[0202] An image pickup device (not shown) composed of a CCD, a CMOS, or the like is disposed on the image plane I.

[0203] A filter FL1 is disposed between the optical system of this embodiment and the image plane I.

[0204] The zoom optical system of this embodiment performs focusing by moving the fourth lens group G4 and the fifth lens group G5 along the optical axis. When focusing from an infinitely focused state to a close-distance object, the fourth lens group G4 is moved from the image side to the object side, and the fifth lens group G5 is moved from the object side to the image side.

[0205] In the zoom optical system of this embodiment, the second lens group G2, the third lens group G3, the fourth lens group G4, the fifth lens group G5, and the sixth lens group G6 correspond to the rear group, and the sixth lens group G6 corresponds to the final lens group. Also, the second lens group G2 corresponds to the first negative lens group, the third lens group G3 corresponds to the first positive lens group, the fourth lens group G4 corresponds to the second positive lens group, and the fifth lens group G5 corresponds to the second negative lens group. Also, the fourth lens group G4 corresponds to the first focusing group and the positive focusing group, and the fifth lens group G5 corresponds to the second focusing group and the negative focusing group.

[0206] Table 2 below lists the specifications of the zoom optical system of this embodiment.

[0207] In Table 2, Bfw represents the back focus at the air-equivalent length of the zoom optical system in the wide-angle state, and Bft represents the back focus at the air-equivalent length of the zoom optical system in the telephoto state.

[0208] (Table 2) [Overall specifications] fw 24.84 ft 67.00 Fnow 4.10 Fnot 4.10 Bfw 12.06 Bft 37.58 [Lens specifications] m r d nd νd (23) (24) (25) 1) 67.159 1.200 1.846660 23.80 2) 45.296 8.873 1.755000 52.34 3) 304.642 d3 4) 127.887 1.919 1.743890 49.53 * 5) 15.932 14.912 6) -57.698 1.500 1.755000 52.34 7) 199.334 1.013 8) 69.130 3.648 2.000690 25.46 P1 9) -155.105 d9 10> ∞ 1.500 (Aperture stop) *11) 19.502 5.108 1.553319 71.68 P2 12) 441.866 0.254 13) 58.720 1.200 1.834810 42.73 14) 23.155 5.413 1.618000 63.34 P2 15) -53.323 1.992 16) -47.176 1.200 1.816000 46.59 17) 13.539 6.663 1.593190 67.90 P2 18) -44.547 d18 19) -22.465 1.200 1.801000 34.92 P1 20) -31.837 4.063 21) 37.168 5.930 1.592014 67.02 *22) -36.742 d22 23) -110.866 1.200 1.589130 61.25 N *24) 82.217 d24 25) -154.025 1.200 1.618000 63.34 N 26) 58.288 d26 27) ∞ 1.600 1.516800 64.13 28) ∞ 0.200 [Aspherical Data] m K A4 A6 A8 A10 A12 A14 5) -1.0000 2.25E-05 4.00E-08 -2.54E-11 1.56E-12 -7.84E-15 1.86E-17 11) 0.0000 -8.04E-06 -1.10E-08 -6.04E-11 -2.10E-14 22) 0.0000 1.64E-05 -1.39E-08 3.12E-11 -2.27E-13 24) 0.0000 6.46E-06 6.55E-09 -3.77E-11 3.26E-13 [Focal Length Data for Each Group] Group Starting Surface Focal Length G1 1 120.85 G2 4 -31.99 G3 11 38.78 G4 19 42.07 G5 23 -79.95 G6 25 -68.28 [Variable interval data] Wide-angle end state Telephoto end state d3 1.520 26.769 d9 25.467 6.262 d18 1.666 8.929 d22 5.905 0.358 d24 6.655 3.050 d26 12.200 37.722

[0209] FIG. 4A is a diagram of various aberrations when focusing on an infinite object in the wide-angle end state of the zoom optical system of the second embodiment, FIG. 4B is a diagram of various aberrations when focusing on an infinite object in the intermediate focal length state of the zoom optical system of the second embodiment, and FIG. 4C is a diagram of various aberrations when focusing on an infinite object in the telephoto end state of the zoom optical system of the second embodiment.

[0210] From each aberration diagram, it can be seen that the zoom optical system of this embodiment effectively suppresses aberration variations during focusing and zooming and has high optical performance.

[0211] (Third Embodiment) FIG. 5 is a cross-sectional view of the zoom optical system of the third embodiment when focusing on an infinite object in the wide-angle end state.

[0212] The zoom optical system of this embodiment has, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, an aperture stop S, a third lens group G3 having a positive refractive power, a fourth lens group G4 having a positive refractive power, a fifth lens group G5 having a negative refractive power, a sixth lens group G6 having a positive refractive power, and a seventh lens group G7 having a negative refractive power.

[0213] The first lens group G1 consists of a positive meniscus lens L1 with a convex surface facing the object side.

[0214] The second lens group G2 consists of, in order from the object side, a negative lens L2 with a plano-concave shape having a concave surface facing the image side, a negative meniscus lens L3 with a convex surface facing the object side, a cemented positive lens formed by a positive meniscus lens L4 with a convex surface facing the object side, and a negative meniscus lens L5 with a concave surface facing the object side.

[0215] The third lens group G3 consists of, in order from the object side, a biconvex positive lens L6, a positive meniscus lens L7 with a convex surface facing the object side, and a negative meniscus lens L8 with a concave surface facing the object side.

[0216] The fourth lens group G4 consists of, in order from the object side, a biconvex positive lens L9, a cemented positive lens formed by a negative meniscus lens L10 with a convex surface facing the object side and a biconvex positive lens L11.

[0217] The fifth lens group G5 consists of a negative meniscus lens L12 with a convex surface facing the object side.

[0218] The sixth lens group G6 consists of, in order from the object side, a biconvex positive lens L13 and a biconvex positive lens L14.

[0219] The seventh lens group G7 consists of a biconcave negative lens L15.

[0220] An imaging device (not shown) composed of a CCD, a CMOS, or the like is disposed on the image plane I.

[0221] The zoom optical system of this embodiment performs focusing by moving the fifth lens group G5 along the optical axis. When focusing from an infinitely focused state to a near-distance object, the fifth lens group G5 is moved from the object side toward the image side.

[0222] In the zoom optical system of this embodiment, the second lens group G2, the third lens group G3, the fourth lens group G4, the fifth lens group G5, the sixth lens group G6, and the seventh lens group G7 belong to the rear group, and the seventh lens group G7 belongs to the final lens group. Further, the second lens group G2 belongs to the first negative lens group, the third lens group G3 belongs to the first positive lens group, the fourth lens group G4 belongs to the second positive lens group, and the fifth lens group G5 belongs to the second negative lens group. Further, the fifth lens group G5 belongs to the negative focusing group.

[0223] The following Table 3 lists the values of the specifications of the zoom optical system of this embodiment.

[0224] (Table 3) [Overall specifications] fw 24.70 ft 101.90 Fnow 4.00 Fnot 4.12 [Lens specifications] m r d nd νd (23) (24) (25) 1) 69.070 5.474 1.752087 52.47 2) 439.840 d2 * 3) ∞ 1.500 1.885373 40.28 4) 22.109 4.545 5) 42.147 1.000 1.489549 80.93 N 6) 21.170 4.738 1.861167 25.66 P1 7) 41.657 5.230 8) -25.535 1.011 1.803585 46.74 9) -37.107 d9 10> ∞ 1.400 (Aperture stop) 11) 295.856 1.867 1.835571 24.07 P1 12) -113.960 0.200 13) 32.140 2.337 1.602919 62.63 P2 14) 125.086 2.085 15) -33.735 2.334 1.919001 29.19 16) -58.214 d16 *17) 30.409 6.839 1.508562 76.49 P2 18) -49.408 0.200 19) 84.317 1.002 1.890613 32.29 20) 19.543 6.528 1.588613 64.15 P2 *21) -88.251 d21 22) 1009.066 1.000 1.930813 30.21 23) 43.640 d23 24) 65.370 3.678 1.855614 24.40 P1 25) -632.954 0.380 26) 80.628 3.324 1.883000 40.66 27) -2737.698 d27 28) -140.459 1.000 1.456000 91.38 N 29) 28.388 Bf [Aspherical Data] m K A4 A6 A8 A10 3) 0.0000 4.90E-06 -1.37E-09 -5.21E-13 5.68E-15 17) 0.0000 -3.60E-06 1.38E-08 -4.49E-11 5.49E-14 21) 0.0000 1.56E-05 2.61E-08 9.57E-12 2.95E-13 [Focal Length Data for Each Group] Group Starting Surface Focal Length G1 1 108.26 G2 3 -23.31 G3 11 72.07 G4 17 36.45 G5 22 -49.03 G6 24 39.51 G7 28 -51.69 [Variable interval data] Wide-angle end state Telephoto end state d2 1.500 38.142 d9 23.111 1.850 d16 10.315 1.500 d21 7.006 2.000 d23 2.971 33.465 d27 4.024 4.217 Bf 18.056 39.081

[0225] FIG. 6A is a diagram of various aberrations when focusing on an infinite object in the wide-angle end state of the zoom optical system of the third embodiment, FIG. 6B is a diagram of various aberrations when focusing on an infinite object in the intermediate focal length state of the zoom optical system of the third embodiment, and FIG. 6C is a diagram of various aberrations when focusing on an infinite object in the telephoto end state of the zoom optical system of the third embodiment.

[0226] From each aberration diagram, it can be seen that the zoom optical system of this embodiment effectively suppresses aberration fluctuations during focusing and zooming and has high optical performance.

[0227] (Fourth Embodiment) FIG. 7 is a cross-sectional view of the zoom optical system of the fourth embodiment when focusing on an infinite object in the wide-angle end state.

[0228] The zoom optical system of this embodiment includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, an aperture stop S, a third lens group G3 having a positive refractive power, a fourth lens group G4 having a positive refractive power, a fifth lens group G5 having a negative refractive power, a sixth lens group G6 having a positive refractive power, a seventh lens group G7 having a positive refractive power, and an eighth lens group G8 having a negative refractive power.

[0229] The first lens group G1 consists of a positive meniscus lens with a convex surface facing the object side.

[0230] The second lens group G2 consists of, in order from the object side, a negative lens L2 with a plano-concave shape having a concave surface facing the image side, a negative meniscus lens L3 with a convex surface facing the object side, a cemented positive lens formed by a positive meniscus lens L4 with a convex surface facing the object side, and a negative meniscus lens L5 with a concave surface facing the object side.

[0231] The third lens group G3 consists of, in order from the object side, a positive meniscus lens L6 with a convex surface facing the object side, a positive lens L7 with a biconvex shape, and a negative meniscus lens L8 with a concave surface facing the object side.

[0232] The fourth lens group G4 consists of, in order from the object side, a positive lens L9 with a biconvex shape, a negative meniscus lens L10 with a convex surface facing the object side, and a cemented positive lens formed by a positive lens L11 with a biconvex shape.

[0233] The fifth lens group G5 consists of a negative meniscus lens L12 with a convex surface facing the object side.

[0234] The sixth lens group G6 consists of a positive lens L13 with a biconvex shape.

[0235] The seventh lens group G7 consists of a positive lens L14 with a biconvex shape.

[0236] The eighth lens group G8 consists of a negative lens L15 with a biconcave shape.

[0237] On the image plane I, an image sensor (not shown) composed of a CCD, a CMOS, or the like is arranged.

[0238] The zoom optical system of this embodiment performs focusing by moving the fifth lens group G5 and the sixth lens group G6 along the optical axis. When focusing from an infinite focus state to a close object, the fifth lens group G5 is moved from the object side to the image side, and the sixth lens group G6 is moved from the image side to the object side.

[0239] In the zoom optical system of this embodiment, the second lens group G2, the third lens group G3, the fourth lens group G4, the fifth lens group G5, the sixth lens group G6, the seventh lens group G7, and the eighth lens group G8 belong to the rear group, and the eighth lens group G8 belongs to the final lens group. Further, the second lens group G2 belongs to the first negative lens group, the third lens group G3 belongs to the first positive lens group, the fourth lens group G4 belongs to the second positive lens group, and the fifth lens group G5 belongs to the second negative lens group. Further, the fifth lens group G5 belongs to the first focusing group and the negative focusing group, and the sixth lens group G6 belongs to the second focusing group and the positive focusing group.

[0240] The following Table 4 lists the values of the specifications of the zoom optical system of this embodiment.

[0241] (Table 4) [Overall specifications] fw 24.70 ft 116.50 Fnow 4.00 Fnot 4.12 [Lens specifications] m r d nd νd (23) (24) (25) 1) 77.446 5.210 1.727296 53.67 2) 584.308 d2 * 3) ∞ 1.000 1.862652 41.96 4) 27.504 4.699 5) 130.462 1.752 1.484196 82.34 N 6) 26.180 4.599 1.857087 24.50 P1 7) 67.904 4.302 8) -30.859 1.000 1.820730 45.17 * 9) -53.767 d9 10> ∞ 1.400 (Aperture stop) 11) 107.826 1.676 1.848261 23.90 P1 12) 621.616 0.200 13) 33.878 3.203 1.620766 60.92 P2 14) -929.742 2.057 15) -32.817 1.000 1.943635 31.37 16) -77.769 d16 *17) 29.728 6.798 1.520726 74.04 P2 18) -46.669 0.371 19) 50.503 1.040 1.892112 32.72 20) 19.569 7.642 1.588166 64.20 P2 *21) -135.546 d21 22) 207.734 1.000 1.953434 32.29 23) 34.501 d23 24) 72.467 2.748 1.846660 23.80 P1 25) -4031.890 d25 26) 760.138 2.738 1.855244 24.37 27) -90.866 d27 28) -56.111 1.000 1.511730 70.00 N 29) 46.882 Bf [Aspherical Data] m K A4 A6 A8 A10 3) 0.0000 4.80E-06 -1.03E-09 1.15E-12 5.58E-15 9) 0.0000 2.15E-06 -3.33E-09 3.17E-11 -6.65E-14 17) 0.0000 -4.97E-06 1.08E-08 -4.23E-11 4.57E-14 21) 0.0000 2.09E-05 3.18E-08 -4.07E-11 5.57E-13 [Focal Length Data for Each Group] Group starting surface focal length G1 1 122.23 G2 3 -25.06 G3 11 95.16 G4 17 29.99 G5 22 -43.51 G6 24 84.11 G7 26 95.04 G8 28 -49.75 [Variable interval data] Wide-angle end state Telephoto end state d2 1.500 42.085 d9 25.504 1.850 d16 11.841 1.500 d21 6.232 2.092 d23 3.379 34.095 d25 1.500 1.500 d27 4.340 7.175 Bf 15.724 34.724

[0242] Figure 8A is a diagram of various aberrations when focusing on an infinite object in the wide-angle end state of the zoom optical system of the fourth embodiment, Figure 8B is a diagram of various aberrations when focusing on an infinite object in the intermediate focal length state of the zoom optical system of the fourth embodiment, and Figure 8C is a diagram of various aberrations when focusing on an infinite object in the telephoto end state of the zoom optical system of the fourth embodiment.

[0243] From each aberration diagram, it can be seen that the zoom optical system of this embodiment effectively suppresses aberration fluctuations during focusing and zooming and has high optical performance.

[0244] (Fifth embodiment) Figure 9 is a cross-sectional view of the zoom optical system of the fifth embodiment when focusing on an infinite object in the wide-angle end state.

[0245] The zoom optical system of this embodiment includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, an aperture stop S, a third lens group G3 having a positive refractive power, a fourth lens group G4 having a positive refractive power, a fifth lens group G5 having a positive refractive power, a sixth lens group G6 having a positive refractive power, and a seventh lens group G7 having a negative refractive power.

[0246] The first lens group G1 consists of a cemented positive lens formed by, in order from the object side, a negative meniscus lens L1 with its convex surface facing the object side and a positive meniscus lens L2 with its convex surface facing the object side.

[0247] The second lens group G2 consists of, in order from the object side, a negative meniscus lens L3 with its convex surface facing the object side, a biconcave negative lens L4, a biconvex positive lens L5, and a negative meniscus lens L6 with its concave surface facing the object side.

[0248] The third lens group G3 consists of, in order from the object side, a positive meniscus lens L7 with its convex surface facing the object side and a positive meniscus lens L8 with its convex surface facing the object side.

[0249] The fourth lens group G4 consists of, in order from the object side, a biconvex positive lens L9 and a cemented negative lens formed by a negative meniscus lens L10 with its convex surface facing the object side and a positive meniscus lens L11 with its convex surface facing the object side.

[0250] The fifth lens group G5 consists of, in order from the object side, a negative meniscus lens L12 with its concave surface facing the object side and a biconvex positive lens L13.

[0251] The sixth lens group G6 consists of a positive meniscus lens L14 with its concave surface facing the object side.

[0252] The seventh lens group G7 consists of a cemented negative lens formed by, in order from the object side, a biconcave negative lens L15 and a positive meniscus lens L16 with its convex surface facing the object side.

[0253] On the image plane I, an imaging element (not shown) composed of a CCD, a CMOS, or the like is disposed.

[0254] The zoom optical system of this embodiment performs focusing by moving the fifth lens group G5 and the sixth lens group G6 along the optical axis. When focusing from an infinitely focused state to a close-distance object, the fifth lens group G5 and the sixth lens group G6 are each moved from the image side toward the object side.

[0255] In the zoom optical system of this embodiment, the second lens group G2, the third lens group G3, the fourth lens group G4, the fifth lens group G5, the sixth lens group G6, and the seventh lens group G7 correspond to the rear group, and the seventh lens group G7 corresponds to the final lens group. Also, the second lens group G2 corresponds to the first negative lens group, the third lens group G3 corresponds to the first positive lens group, the fourth lens group G4 corresponds to the second positive lens group, and the seventh lens group G7 corresponds to the second negative lens group. Further, the fifth lens group G5 corresponds to the first focusing group, the sixth lens group G6 corresponds to the second focusing group, and the fifth lens group G5 and the sixth lens group G6 correspond to the positive focusing group.

[0256] The following Table 5 lists the specifications of the zoom optical system of this embodiment.

[0257] (Table 5) [Overall specifications] fw 24.70 ft 116.50 Fnow 4.00 Fnot 4.12 [Lens specifications] m r d nd νd (23) (24) (25) 1) 61.204 1.800 1.903660 31.27 2) 43.500 9.290 1.618000 63.34 3) 599.325 d3 * 4) 8892.243 1.400 1.775030 47.31 5) 21.486 7.770 6) -67.187 1.500 1.834000 37.18 7) 139.906 0.230 8) 60.170 4.730 1.854510 25.15 P1 9) -60.170 1.960 10) -27.165 1.100 1.497820 82.57 N 11) -128.171 d11 12> ∞ 0.880 (Open aperture) *13) 34.508 3.660 1.593060 66.97 P2 14) 131.359 0.200 15) 51.576 2.030 1.618000 63.34 P2 16) 76.388 d16 17) 33.398 5.600 1.497820 82.57 P2 18) -112.939 1.450 19) 51.317 1.100 1.900430 37.38 20) 17.933 6.550 1.497820 82.57 P2 21) 1939.354 d21 22) -28.100 1.100 1.784720 25.64 23) -52.294 0.200 24) 156.708 4.090 1.772500 49.62 25) -53.421 d25 26) -214.076 3.800 1.553320 71.67 P2 *27) -36.775 d27 *28) -43.094 1.300 1.775030 47.31 29) 37.433 3.600 1.922860 20.88 P1 30) 81.956 Bf [Aspherical data] m K A4 A6 A8 A10 A12 A14 4) 0.0000 6.78E-06 -9.11E-09 2.14E-11 -6.61E-15 -7.48E-17 1.46E-19 13) 0.0000 -7.33E-06 1.12E-09 -3.78E-12 -5.24E-15 27) 0.0000 1.69E-05 -8.63E-09 5.71E-12 -9.88E-15 28) 0.0000 2.41E-06 1.50E-09 -1.37E-10 6.99E-13 -1.28E-15 -1.88E-19 [Focus distance data for each group] Group Starting surface Focus distance G1 1 136.58 G2 4 -24.06 G3 13 59.44 G4 17 67.49 G5 22 135.76 G6 26 79.64 G7 28 -38.93 [Variable interval data] Wide-angle end state Telephoto end state d3 1.525 46.708 d11 24.145 2.370 d16 9.007 1.400 d21 6.277 18.040 d25 2.000 5.177 d27 9.107 1.773 Bf 13.555 45.147

[0258] FIG. 10A is a diagram of various aberrations when focusing on an infinite object in the wide-angle end state of the zoom optical system of the fifth embodiment, FIG. 10B is a diagram of various aberrations when focusing on an infinite object in the intermediate focal length state of the zoom optical system of the fifth embodiment, and FIG. 10C is a diagram of various aberrations when focusing on an infinite object in the telephoto end state of the zoom optical system of the fifth embodiment.

[0259] From each aberration diagram, it can be seen that the zoom optical system of this embodiment effectively suppresses the aberration variations during focusing and zooming, and has high optical performance.

[0260] (Sixth Embodiment) FIG. 11 is a cross-sectional view of the zoom optical system of the sixth embodiment when focusing on an infinite object in the wide-angle end state.

[0261] The zoom optical system of this embodiment includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, an aperture stop S, a third lens group G3 having a positive refractive power, a fourth lens group G4 having a negative refractive power, a fifth lens group G5 having a positive refractive power, a sixth lens group G6 having a negative refractive power, and a seventh lens group G7 having a positive refractive power.

[0262] The first lens group G1 is composed of a cemented positive lens including a negative meniscus lens L1 with its convex surface facing the object side and a biconvex positive lens L2, in order from the object side.

[0263] The second lens group G2 is composed of a cemented negative lens including a negative meniscus lens L3 with its convex surface facing the object side and a negative meniscus lens L4 with its convex surface facing the object side, a cemented positive lens including a biconcave negative lens L5 and a biconvex positive lens L6, and a negative meniscus lens L7 with its concave surface facing the object side, in order from the object side.

[0264] The third lens group G3 is composed of a biconvex positive lens L8 and a biconvex positive lens L9, in order from the object side.

[0265] The fourth lens group G4 is composed of a cemented negative lens including a biconcave negative lens L10 and a positive meniscus lens L11 with its convex surface facing the object side, and a positive meniscus lens L12 with its convex surface facing the object side, in order from the object side.

[0266] The fifth lens group G5 consists of, in order from the object side, a biconvex positive lens L13, a cemented negative lens composed of a biconvex positive lens L14 and a biconcave negative lens L15, a cemented negative lens composed of a negative meniscus lens L16 with its convex surface facing the object side and a biconvex positive lens L17, and a biconvex positive lens L18.

[0267] The sixth lens group G6 consists of, in order from the object side, a positive meniscus lens L19 with its concave surface facing the object side and a biconcave negative lens L20.

[0268] The seventh lens group G7 consists of a positive meniscus lens L21 with its convex surface facing the object side.

[0269] An imaging device (not shown) composed of a CCD, a CMOS, or the like is disposed on the image plane I.

[0270] In the zoom optical system of this embodiment, focusing is performed by moving the sixth lens group G6 along the optical axis. When the sixth lens group G6 is focused from an infinite state to a close object, it is moved from the object side toward the image side.

[0271] In the zoom optical system of this embodiment, the second lens group G2, the third lens group G3, the fourth lens group G4, the fifth lens group G5, the sixth lens group G6, and the seventh lens group G7 correspond to the rear group, and the seventh lens group G7 corresponds to the final lens group. Also, the second lens group G2 corresponds to the first negative lens group, the third lens group G3 corresponds to the first positive lens group, the fourth lens group G4 corresponds to the second negative lens group, and the fifth lens group G5 corresponds to the second positive lens group. Also, the sixth lens group G6 corresponds to the negative focusing group.

[0272] The following Table 6 lists the values of the specifications of the zoom optical system of this embodiment.

[0273] (Table 6) [Overall specifications] fw 24.70 ft 116.50 Fnow 4.10 Fnot 4.10 [Lens Specifications] m r d nd νd (23) (24) (25) * 1) 60.967 2.000 1.953750 32.33 2) 42.237 8.537 1.618000 63.34 3) -3319.753 d3 4) 426.783 0.100 1.560930 36.64 5) 278.283 1.200 1.883000 40.69 6) 22.697 6.425 7) -70.255 1.200 1.618000 63.34 N 8) 28.843 4.893 1.850250 30.05 P1 9) -92.169 1.309 10) -37.069 1.000 1.755000 52.34 11) -200.602 d11 12> ∞ 1.500 (Aperture Stop) 13) 41.043 3.957 1.497820 82.57 P2 14) -112.702 0.200 15) 50.383 3.908 1.593240 67.90 P2 *16) -73.304 d16 17) -44.208 1.000 1.696800 55.52 18) 54.606 0.100 1.560930 36.64 *19) 54.619 0.200 20) 32.260 2.040 1.846660 23.80 P1 21) 50.118 d21 *22) 38.298 4.049 1.593240 67.90 P2 23) -50.338 0.200 24) 66.052 4.718 1.755000 52.34 25) -25.774 1.000 1.950000 29.37 26) 36.234 1.627 27) 328.661 1.000 1.950000 29.37 28) 25.731 5.492 1.487490 70.31 P2 29) -46.438 0.200 30) 38.196 4.498 1.850000 27.03 P1 31) -143.789 d31 32) -102.642 2.859 1.672700 32.19 P1 33) -40.067 4.819 34) -33.105 1.200 1.696800 55.52 35) 33.390 d35 36) 90.269 2.873 1.846660 23.80 P1 37) 637.643 Bf [Aspherical Data] m K A4 A6 A8 A10 1) -1.0000 2.89E-06 -2.02E-09 7.60E-12 -1.67E-14 16) 0.0000 6.47E-06 -4.63E-09 -3.91E-12 2.63E-14 19) 0.0000 -5.70E-06 2.86E-08 -6.41E-11 5.59E-14 22) 0.0000 -1.01E-05 1.59E-08 -7.06E-11 1.42E-13 [Focal Length Data for Each Group] Group Starting Surface Focal Length G1 1 125.04 G2 4 -21.06 G3 13 28.56 G4 17 -52.12 G5 22 34.93 G6 32 -33.33 G7 36 123.90 [Variable interval data] Wide-angle end state Telephoto end state d3 1.500 41.533 d11 24.224 1.500 d16 2.407 11.409 d21 10.502 1.500 d31 2.120 2.268 d35 4.113 23.421 Bf 14.555 27.789

[0274] Figure 12A is a diagram of various aberrations when focusing on an infinite object in the wide-angle end state of the zoom optical system of the sixth embodiment, Figure 12B is a diagram of various aberrations when focusing on an infinite object in the intermediate focal length state of the zoom optical system of the sixth embodiment, and Figure 12C is a diagram of various aberrations when focusing on an infinite object in the telephoto end state of the zoom optical system of the sixth embodiment.

[0275] From each aberration diagram, it can be seen that the zoom optical system of this embodiment effectively suppresses aberration fluctuations during focusing and zooming and has high optical performance.

[0276] (Seventh embodiment) Figure 13 is a cross-sectional view of the zoom optical system of the seventh embodiment when focusing on an infinite object in the wide-angle end state.

[0277] The zoom optical system of this embodiment includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, an aperture stop S, a third lens group G3 having a positive refractive power, a fourth lens group G4 having a positive refractive power, a fifth lens group G5 having a negative refractive power, a sixth lens group G6 having a positive refractive power, a seventh lens group G7 having a positive refractive power, and an eighth lens group G8 having a negative refractive power.

[0278] The first lens group G1 consists of a positive meniscus lens L1 with a convex surface facing the object side.

[0279] The second lens group G2 includes, in order from the object side, a biconcave negative lens L2, a negative meniscus lens L3 with its convex surface facing the object side, a cemented positive lens composed of a positive meniscus lens L4 with its convex surface facing the object side, and a negative meniscus lens L5 with its concave surface facing the object side.

[0280] The third lens group G3 includes, in order from the object side, a biconvex positive lens L6, a positive meniscus lens L7 with its convex surface facing the object side, and a negative meniscus lens L8 with its concave surface facing the object side.

[0281] The fourth lens group G4 includes, in order from the object side, a biconvex positive lens L9, a negative meniscus lens L10 with its convex surface facing the object side, and a cemented positive lens composed of two biconvex positive lenses L11.

[0282] The fifth lens group G5 consists of a negative meniscus lens L12 with its convex surface facing the object side.

[0283] The sixth lens group G6 includes, in order from the object side, a biconvex positive lens L13 and a negative meniscus lens L14 with its convex surface facing the object side.

[0284] The seventh lens group G7 consists of a biconvex positive lens L15.

[0285] The eighth lens group G8 consists of a biconcave negative lens L16.

[0286] An image sensor (not shown) composed of a CCD, a CMOS, or the like is disposed on the image plane I.

[0287] In the zoom optical system of this embodiment, focusing is performed by moving the fifth lens group G5 and the seventh lens group G7 along the optical axis. When focusing from an infinite focus state to a close object, the fifth lens group G5 is moved from the object side toward the image side, and the seventh lens group G7 is moved from the image side toward the object side.

[0288] In the zoom optical system of this embodiment, the second lens group G2, the third lens group G3, the fourth lens group G4, the fifth lens group G5, the sixth lens group G6, the seventh lens group G7, and the eighth lens group G8 belong to the rear group, and the eighth lens group G8 belongs to the final lens group. Further, the second lens group G2 belongs to the first negative lens group, the third lens group G3 belongs to the first positive lens group, the fourth lens group G4 belongs to the second positive lens group, and the fifth lens group G5 belongs to the second negative lens group. Further, the fifth lens group G5 belongs to the first focusing group and the negative focusing group, and the seventh lens group G7 belongs to the second focusing group and the positive focusing group.

[0289] The following Table 7 lists the values of the specifications of the zoom optical system of this embodiment.

[0290] (Table 7) [Overall specifications] fw 24.70 ft 116.50 Fnow 4.00 Fnot 4.12 [Lens specifications] m r d nd νd (23) (24) (25) 1) 79.267 5.328 1.610028 61.92 2) 1211.020 d2 * 3) -666.001 1.000 1.846765 43.08 4) 28.956 4.106 5) 119.464 1.000 1.488366 81.23 N 6) 23.990 5.694 1.859720 25.58 P1 7) 75.610 3.523 8) -40.022 1.000 1.858890 42.22 * 9) -119.737 d9 10> ∞ 1.400 (Aperture stop) 11) 118.226 1.928 1.887426 26.67 P1 12) -502.479 0.200 13) 32.921 3.197 1.619109 61.07 P2 14) 3093.936 1.947 15) -36.444 1.000 1.951916 32.14 16) -121.050 d16 *17) 31.693 6.478 1.527617 72.77 P2 18) -45.685 0.200 19) 50.306 1.000 1.888302 31.72 20) 17.709 7.435 1.590315 63.96 P2 *21) -188.818 d21 22) 1078.096 1.000 1.952697 32.41 23) 53.346 d23 24) 45.805 3.800 1.846660 23.80 P1 25) -165.803 0.200 26) 83.490 1.000 1.863249 41.92 27) 32.358 d27 28) 520.111 3.315 1.786942 48.44 29) -71.011 d29 30) -27.595 1.000 1.456000 91.38 N 31) 102.771 Bf [Aspherical Data] m K A4 A6 A8 A10 3) 0.0000 5.62E-06 -2.41E-09 1.96E-12 3.09E-15 9) 0.0000 3.88E-06 -2.95E-09 1.22E-12 17) 0.0000 -4.03E-06 -5.75E-10 -1.45E-11 21) 0.0000 1.68E-05 9.33E-09 2.56E-11 [Focus distance data for each group] Group Starting surface Focus distance G1 1 138.79 G2 3 -25.57 G3 11 86.31 G4 17 32.32 G5 22 -58.94 G6 24 121.47 G7 28 79.59 G8 30 -47.59 [Variable interval data] Wide-angle end state Telephoto end state d2 1.500 45.179 d9 25.296 1.850 d16 11.979 1.400 d21 4.517 2.000 d23 3.091 27.107 d27 4.991 12.096 d29 5.275 4.684 Bf 12.055 29.388

[0291] FIG. 14A is a diagram of various aberrations when focusing on an infinite object in the wide-angle end state of the zoom optical system of the seventh embodiment, FIG. 14B is a diagram of various aberrations when focusing on an infinite object in the intermediate focus distance state of the zoom optical system of the seventh embodiment, and FIG. 14C is a diagram of various aberrations when focusing on an infinite object in the telephoto end state of the zoom optical system of the seventh embodiment.

[0292] From each aberration diagram, it can be seen that the zoom optical system of this embodiment effectively suppresses the aberration variation during focusing and zooming and has high optical performance.

[0293] (Eighth embodiment) FIG. 15 is a cross-sectional view of the zoom optical system of the eighth embodiment when focusing on an infinite object in the wide-angle end state.

[0294] The zoom optical system of this embodiment includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, an aperture stop S, a third lens group G3 having a positive refractive power, a fourth lens group G4 having a positive refractive power, a fifth lens group G5 having a negative refractive power, and a sixth lens group G6 having a negative refractive power.

[0295] The first lens group G1 consists of a cemented positive lens formed by, in order from the object side, a negative meniscus lens L1 with its convex surface facing the object side and a positive meniscus lens L2 with its convex surface facing the object side.

[0296] The second lens group G2 consists of, in order from the object side, a negative meniscus lens L3 with its convex surface facing the object side, a biconcave negative lens L4, a biconvex positive lens L5, and a biconcave negative lens L6.

[0297] The third lens group G3 consists of, in order from the object side, a biconvex positive lens L7, a cemented positive lens formed by a negative meniscus lens L8 with its convex surface facing the object side and a biconvex positive lens L9, and a negative meniscus lens L10 with its concave surface facing the object side.

[0298] The fourth lens group G4 consists of, in order from the object side, a cemented positive lens formed by a biconvex positive lens L11 and a negative meniscus lens L12 with its concave surface facing the object side, and a cemented positive lens formed by a negative meniscus lens L13 with its convex surface facing the object side and a biconvex positive lens L14.

[0299] The fifth lens group G5 consists of, in order from the object side, a cemented negative lens formed by a biconvex positive lens L15 and a biconcave negative lens L16.

[0300] The sixth lens group G6 consists of, in order from the object side, a biconcave negative lens L17 and a biconvex positive lens L18.

[0301] An imaging device (not shown) composed of a CCD, a CMOS, or the like is disposed on the image plane I.

[0302] The zoom optical system of this embodiment performs focusing by moving the fifth lens group G5 along the optical axis. When focusing from an infinitely focused state to a nearby object, the fifth lens group G5 is moved from the object side to the image side.

[0303] In the zoom optical system of this embodiment, the second lens group G2, the third lens group G3, the fourth lens group G4, the fifth lens group G5, and the sixth lens group G6 belong to the rear group, and the sixth lens group G6 belongs to the final lens group. Also, the second lens group G2 belongs to the first negative lens group, the third lens group G3 belongs to the first positive lens group, the fourth lens group G4 belongs to the second positive lens group, and the fifth lens group G5 belongs to the second negative lens group. Further, the fifth lens group G5 belongs to the negative focusing group.

[0304] The following Table 8 lists the values of the specifications of the zoom optical system of this embodiment.

[0305] (Table 8) [Overall specifications] fw 24.75 ft 193.60 Fnow 4.00 Fnot 6.50 [Lens specifications] m r d nd νd (23) (25) 1) 50.215 2.000 1.903660 31.27 2) 34.572 9.588 1.603000 65.44 3) 1311.519 d3 4) 734.769 1.307 1.953750 32.33 5) 18.756 4.799 6) -48.834 1.129 1.755000 52.33 7) 82.569 0.451 8) 35.539 3.409 1.922860 20.88 P1 9) -55.882 0.297 10) -40.429 1.015 1.816000 46.59 11) 149.588 d11 12> ∞ 2.016 (Aperture stop) 13) 45.792 2.740 1.902650 35.72 P1 14) -158.052 0.500 15) 51.626 1.000 2.001000 29.12 16) 25.348 3.645 1.579570 53.74 17) -47.120 1.756 18) -28.990 1.043 1.953750 32.33 19) -180.881 d19 20) 31.325 6.348 1.834810 42.73 P1 21) -46.677 1.000 1.903660 31.27 22) -434.420 0.175 23) 31.122 2.824 1.953750 32.33 24) 15.393 10.000 1.497100 81.49 P2 *25) -46.610 d25 26) 192.398 3.146 1.846660 23.80 P1 27) -50.784 1.017 1.851350 40.13 *28) 33.031 d28 29) -39.648 1.400 1.820800 42.51 *30) 237.062 0.232 31) 46.735 4.880 1.683760 37.57 P1 32) -359.761 Bf [Aspherical data] m K A4 A6 A8 A10 A12 25) 0.0000 3.31E-05 -5.07E-08 7.86E-10 -4.83E-12 1.35E-14 28) 0.0000 -3.68E-06 5.73E-08 -1.75E-10 -8.02E-13 5.32E-15 30) 0.0000 7.67E-06 -1.25E-08 6.72E-11 -1.62E-13 [Focus distance data for each group] Group Starting surface Focus distance G1 1 110.64 G2 4 -16.88 G3 13 59.63 G4 20 27.13 G5 26 -47.14 G6 29 -137.34 [Variable interval data] Wide-angle end state Telephoto end state d3 1.969 54.765 d11 17.288 1.166 d19 14.645 1.478 d25 4.685 2.612 d28 8.395 23.634 Bf 11.793 37.548

[0306] FIG. 16A is a diagram of various aberrations when focusing on an infinite object in the intermediate focal length state of the zoom optical system of the eighth embodiment, FIG. 16B is a diagram of various aberrations when focusing on an infinite object in the telephoto end state of the zoom optical system of the eighth embodiment, and FIG. 16C is a diagram of various aberrations when focusing on an infinite object in the wide-angle end state of the zoom optical system of the eighth embodiment.

[0307] From each aberration diagram, it can be seen that the zoom optical system of this embodiment effectively suppresses aberration fluctuations during focusing and zooming and has high optical performance.

[0308] (Ninth Embodiment) FIG. 17 is a cross-sectional view of the zoom optical system of the ninth embodiment when focusing on an infinite object in the wide-angle end state.

[0309] The zoom optical system of this embodiment includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, an aperture stop S, a third lens group G3 having a positive refractive power, a fourth lens group G4 having a positive refractive power, a fifth lens group G5 having a negative refractive power, and a sixth lens group G6 having a negative refractive power.

[0310] The first lens group G1 is composed of a cemented positive lens including, in order from the object side, a negative meniscus lens L1 with a convex surface facing the object side and a positive meniscus lens L2 with a convex surface facing the object side.

[0311] The second lens group G2 is composed of, in order from the object side, a negative meniscus lens L3 with a convex surface facing the object side, a biconcave negative lens L4, a biconvex positive lens L5, and a biconcave negative lens L6.

[0312] The third lens group G3 is composed of, in order from the object side, a biconvex positive lens L7, a cemented positive lens of a negative meniscus lens L8 with a convex surface facing the object side and a biconvex positive lens L9, and a negative meniscus lens L10 with a concave surface facing the object side.

[0313] The fourth lens group G4 is composed of, in order from the object side, a cemented positive lens of a biconvex positive lens L11 and a negative meniscus lens L12 with a concave surface facing the object side, and a cemented positive lens of a negative meniscus lens L13 with a convex surface facing the object side and a biconvex positive lens L14.

[0314] The fifth lens group G5 is composed of, in order from the object side, a cemented negative lens of a biconvex positive lens L15 and a biconcave negative lens L16.

[0315] The sixth lens group G6 is composed of, in order from the object side, a biconcave negative lens L17 and a biconvex positive lens L18.

[0316] An imaging device (not shown) composed of a CCD, a CMOS, or the like is disposed on the image plane I.

[0317] The zoom optical system of this embodiment performs focusing by moving the fourth lens group G4 and the fifth lens group G5 along the optical axis. When focusing from an infinite focus state to a close - distance object, the fourth lens group G4 and the fifth lens group G5 are each moved from the object side to the image side.

[0318] In the zoom optical system of this embodiment, the second lens group G2, the third lens group G3, the fourth lens group G4, the fifth lens group G5, and the sixth lens group G6 belong to the rear group, and the sixth lens group G6 belongs to the final lens group. Also, the second lens group G2 corresponds to the first negative lens group, the third lens group G3 corresponds to the first positive lens group, the fourth lens group G4 corresponds to the second positive lens group, and the fifth lens group G5 corresponds to the second negative lens group. Further, the fourth lens group G4 corresponds to the first focusing group and the positive focusing group, and the fifth lens group G5 corresponds to the second focusing group and the negative focusing group.

[0319] The following Table 9 lists the values of the specifications of the zoom optical system of this embodiment.

[0320] (Table 9) [Overall specifications] fw 24.75 ft 193.60 Fnow 4.00 Fnot 6.50 [Lens specifications] m r d nd νd (23) (25) 1) 50.215 2.000 1.903660 31.27 2) 34.572 9.588 1.603000 65.44 3) 1311.519 d3 4) 734.769 1.307 1.953750 32.33 5) 18.756 4.799 6) -48.834 1.129 1.755000 52.33 7) 82.569 0.451 8) 35.539 3.409 1.922860 20.88 P1 9) -55.882 0.297 10) -40.429 1.015 1.816000 46.59 11) 149.588 d11 12> ∞ 2.016 (Aperture diaphragm) 13) 45.792 2.740 1.902650 35.72 P1 14) -158.052 0.500 15) 51.626 1.000 2.001000 29.12 16) 25.348 3.645 1.579570 53.74 17) -47.120 1.756 18) -28.990 1.043 1.953750 32.33 19) -180.881 d19 20) 31.325 6.348 1.834810 42.73 P1 21) -46.677 1.000 1.903660 31.27 22) -434.420 0.175 23) 31.122 2.824 1.953750 32.33 24) 15.393 10.000 1.497100 81.49 P2 *25) -46.610 d25 26) 192.398 3.146 1.846660 23.80 P1 27) -50.784 1.017 1.851350 40.13 *28) 33.031 d28 29) -39.648 1.400 1.820800 42.51 *30) 237.062 0.232 31) 46.735 4.880 1.683760 37.57 P1 32) -359.761 Bf [Aspherical data] m K A4 A6 A8 A10 A12 25) 0.0000 3.31E-05 -5.07E-08 7.86E-10 -4.83E-12 1.35E-14 28) 0.0000 -3.68E-06 5.73E-08 -1.75E-10 -8.02E-13 5.32E-15 30) 0.0000 7.67E-06 -1.25E-08 6.72E-11 -1.62E-13 [Focal distance data for each group] Group Starting surface Focal distance G1 1 110.64 G2 4 -16.88 G3 13 59.63 G4 20 27.13 G5 26 -47.14 G6 29 -137.34 [Variable interval data] Wide-angle end state Telephoto end state d3 1.969 54.765 d11 17.288 1.166 d19 14.645 1.478 d25 4.685 2.612 d28 8.395 23.634 Bf 11.793 37.548

[0321] FIG. 18A is a diagram of various aberrations when focusing on an infinite object in the intermediate focal length state of the zoom optical system of the ninth embodiment, FIG. 18B is a diagram of various aberrations when focusing on an infinite object in the telephoto end state of the zoom optical system of the ninth embodiment, and FIG. 18C is a diagram of various aberrations when focusing on an infinite object in the wide-angle end state of the zoom optical system of the ninth embodiment.

[0322] From each aberration diagram, it can be seen that the zoom optical system of this embodiment effectively suppresses the aberration fluctuations during focusing and zooming and has high optical performance.

[0323] (Tenth Embodiment) FIG. 19 is a cross-sectional view of the zoom optical system of the tenth embodiment when focusing on an infinite object in the wide-angle end state.

[0324] The zoom optical system of this embodiment includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, an aperture stop S, a third lens group G3 having a positive refractive power, a fourth lens group G4 having a positive refractive power, a fifth lens group G5 having a negative refractive power, a sixth lens group G6 having a negative refractive power, and a seventh lens group G7 having a positive refractive power.

[0325] The first lens group G1 consists of a cemented positive lens formed by, in order from the object side, a negative meniscus lens L1 with a convex surface facing the object side and a positive meniscus lens L2 with a convex surface facing the object side.

[0326] The second lens group G2 consists of, in order from the object side, a negative meniscus lens L3 with a convex surface facing the object side, a cemented positive lens formed by a biconcave negative lens L4 and a positive meniscus lens L5 with a convex surface facing the object side, and a negative meniscus lens L6 with a concave surface facing the object side.

[0327] The third lens group G3 consists of, in order from the object side, a positive meniscus lens L7 with a convex surface facing the object side and a positive meniscus lens L8 with a convex surface facing the object side.

[0328] The fourth lens group G4 consists of, in order from the object side, a cemented positive lens formed by a negative meniscus lens L9 with a convex surface facing the object side and a positive meniscus lens L10 with a convex surface facing the object side, a cemented negative lens formed by a biconvex positive lens L11 and a negative meniscus lens L12 with a concave surface facing the object side, and a biconvex positive lens L13.

[0329] The fifth lens group G5 consists of, in order from the object side, a positive meniscus lens L14 with a concave surface facing the object side and a biconcave negative lens L15.

[0330] The sixth lens group G6 consists of a biconcave negative lens L16.

[0331] The seventh lens group G7 consists of a positive meniscus lens L17 with a convex surface facing the object side.

[0332] An imaging element (not shown) composed of a CCD, a CMOS, or the like is disposed on the image plane I.

[0333] In the zoom optical system of this embodiment, focusing is performed by moving the fifth lens group G5 and the sixth lens group G6 along the optical axis. When focusing from an infinitely focused state to a close object, the fifth lens group G5 and the sixth lens group G6 are each moved from the object side to the image side.

[0334] In the zoom optical system of this embodiment, the second lens group G2, the third lens group G3, the fourth lens group G4, the fifth lens group G5, the sixth lens group G6, and the seventh lens group G7 correspond to the rear group, and the seventh lens group G7 corresponds to the final lens group. Further, the second lens group G2 corresponds to the first negative lens group, the third lens group G3 corresponds to the first positive lens group, the fourth lens group G4 corresponds to the second positive lens group, and the fifth lens group G5 corresponds to the second negative lens group. Further, the fifth lens group G5 corresponds to the first focusing group, the sixth lens group G6 corresponds to the second focusing group, and the fifth lens group G5 and the sixth lens group G6 correspond to the negative focusing group.

[0335] The following Table 10 lists the values of the specifications of the zoom optical system of this embodiment.

[0336] (Table 10) [Overall specifications] fw 28.00 ft 194.00 Fnow 4.37 Fnot 6.57 [Lens specifications] m r d nd νd (23) (24) (25) 1) 63.743 2.000 1.749500 35.25 2) 40.141 10.350 1.593190 67.90 3) 9735.642 d3 * 4) 158.701 1.500 1.773870 47.25 * 5) 22.089 5.915 6) -167.771 1.000 1.497820 82.57 N 7) 20.719 4.566 1.850000 27.03 P1 8) 79.584 2.363 9) -46.857 1.000 1.834810 42.73 10) -393.371 d10 11> ∞ 2.000 (Open aperture) *12) 25.238 2.790 1.592450 66.92 P2 13) 59.114 0.200 14) 26.374 2.366 1.617720 49.81 15) 38.522 d15 16) 23.189 2.580 1.902650 35.77 17) 13.857 5.703 1.497820 82.57 P2 18) 693.648 1.004 19) 752.104 4.789 1.517420 52.20 20) -18.856 1.000 2.000690 25.46 21) -60.570 0.200 *22) 443.772 4.473 1.517420 52.20 23) -23.063 d23 24) -308.609 5.485 1.945944 17.98 25) -37.228 1.504 26) -58.034 1.000 1.834000 37.18 27) 84.476 d27 *28) -39.484 1.500 1.773870 47.25 29) 108.384 d29 30) 38.120 2.261 1.834000 37.18 31) 43.033 Bf [Aspherical data] m K A4 A6 A8 A10 4) 0.0000 7.29E-07 2.06E-08 -4.49E-11 2.79E-14 5) 0.0000 2.28E-06 3.23E-08 4.83E-11 2.02E-13 12) 0.0000 -9.41E-06 -1.09E-09 4.05E-11 -1.20E-13 22) 0.0000 -3.09E-05 2.57E-08 -7.88E-12 3.97E-13 28) 0.0000 -6.15E-06 -1.61E-08 3.82E-11 -1.85E-14 [Focal length data for each group] Group Starting surface Focal length G1 1 127.24 G2 4 -21.51 G3 12 45.92 G4 16 42.44 G5 24 -980.13 G6 28 -37.23 G7 30 331.08 [Variable interval data] Wide-angle end state Telephoto end state d3 2.000 51.261 d10 25.674 2.000 d15 9.525 2.000 d23 3.205 2.269 d27 5.176 5.639 d29 4.174 37.020 Bf 13.579 36.718

[0337] FIG. 20A is a diagram of various aberrations when focusing on an infinite object in the wide-angle end state of the zoom optical system of the tenth embodiment, FIG. 20B is a diagram of various aberrations when focusing on an infinite object in the intermediate focal length state of the zoom optical system of the tenth embodiment, and FIG. 20C is a diagram of various aberrations when focusing on an infinite object in the telephoto end state of the zoom optical system of the tenth embodiment.

[0338] From each aberration diagram, it can be seen that the zoom optical system of this embodiment effectively suppresses aberration fluctuations during focusing and zooming and has high optical performance.

[0339] (Eleventh Embodiment) FIG. 21 is a cross-sectional view of the zoom optical system of the eleventh embodiment when focusing on an infinite object in the wide-angle end state.

[0340] The zoom optical system of this embodiment includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, an aperture stop S, a third lens group G3 having a positive refractive power, a fourth lens group G4 having a negative refractive power, a fifth lens group G5 having a positive refractive power, a sixth lens group G6 having a positive refractive power, and a seventh lens group G7 having a negative refractive power.

[0341] The first lens group G1 consists of a cemented positive lens formed by, in order from the object side, a negative meniscus lens L1 with a convex surface facing the object side and a biconvex positive lens L2.

[0342] The second lens group G2 consists of, in order from the object side, a biconcave negative lens L3, a biconcave negative lens L4, a biconvex positive lens L5, and a biconcave negative lens L6.

[0343] The third lens group G3 consists of, in order from the object side, a biconvex positive lens L7 and a cemented negative lens formed by a negative meniscus lens L8 with a convex surface facing the object side and a positive meniscus lens L9 with a convex surface facing the object side.

[0344] The fourth lens group G4 consists of, in order from the object side, a biconvex positive lens L10, a biconcave negative lens L11, and a cemented negative lens formed by a positive meniscus lens L12 with its convex surface facing the object side.

[0345] The fifth lens group G5 consists of, in order from the object side, a cemented positive lens formed by a negative meniscus lens L13 with its convex surface facing the object side and a positive meniscus lens L14 with its convex surface facing the object side.

[0346] The sixth lens group G6 consists of a biconvex positive lens L15.

[0347] The seventh lens group G7 consists of, in order from the object side, a biconcave negative lens L16, a biconvex positive lens L17, and a plano-concave negative lens L18 with its concave surface facing the object side.

[0348] On the image plane I, an imaging device (not shown) composed of a CCD, a CMOS, or the like is arranged.

[0349] The zoom optical system of this embodiment performs focusing by moving the fifth lens group G5 and the sixth lens group G6 along the optical axis. When focusing from an infinitely focused state to a close-distance object, the fifth lens group G5 and the sixth lens group G6 are each moved from the image side to the object side.

[0350] In the zoom optical system of this embodiment, the second lens group G2, the third lens group G3, the fourth lens group G4, the fifth lens group G5, the sixth lens group G6, and the seventh lens group G7 correspond to the rear groups, and the seventh lens group G7 corresponds to the final lens group. Also, the second lens group G2 corresponds to the first negative lens group, the third lens group G3 corresponds to the first positive lens group, the fourth lens group G4 corresponds to the second negative lens group, and the fifth lens group G5 corresponds to the second positive lens group. Also, the fifth lens group G5 corresponds to the first focusing group, the sixth lens group G6 corresponds to the second focusing group, and the fifth lens group G5 and the sixth lens group G6 correspond to the positive focusing groups.

[0351] The following Table 11 lists the values of the specifications of the zoom optical system of this embodiment.

[0352] (Table 11) [Overall specifications] fw 24.70 ft 233.00 Fnow 4.50 Fnot 6.57 [Lens specifications] m r d nd νd (23) (25) 1) 59.540 1.800 1.902650 35.77 2) 41.859 11.321 1.593190 67.90 3) -1956.315 d3 * 4) -379.614 1.500 1.773870 47.25 5) 21.088 6.883 6) -118.229 1.000 1.950000 29.37 7) 89.211 0.200 8) 38.887 5.729 1.860740 23.08 P1 9) -55.015 1.189 10) -34.049 1.000 1.816000 46.59 11) 19309.949 d11 12> ∞ 2.000 (Aperture stop) *13) 23.950 5.797 1.592450 66.92 P2 14) -162.098 0.200 15) 35.893 1.000 1.834810 42.73 16) 22.737 2.714 1.592700 35.27 P1 17) 30.251 d17 18) 26.148 5.048 1.593190 67.90 P2 19) -98.728 1.059 20) -84.013 1.000 2.000690 25.46 21) 20.844 4.119 1.593190 67.90 22) 163.041 d22 23) 23.630 1.000 1.902650 35.77 24) 12.909 6.589 1.728250 28.38 25) 150.766 d25 26) 48.329 2.746 1.548141 45.78 P1 *27) -404.148 d27 28) -65.371 1.000 1.816000 46.59 29) 26.189 0.850 30) 34.959 6.023 1.688930 31.16 P1 31) -33.122 1.371 *32) -22.123 1.300 1.773870 47.25 33) ∞ Bf [Aspherical Data] m K A4 A6 A8 A10 4) 0.0000 2.64E-06 -1.77E-09 5.14E-12 -3.69E-15 13) 0.0000 -1.00E-05 -3.09E-09 -1.67E-11 -9.99E-15 27) 0.0000 2.31E-05 -1.32E-09 -3.88E-11 -1.96E-12 32) 0.0000 6.59E-06 1.96E-08 -1.08E-10 5.11E-13 [Focal Length Data for Each Group] Group Starting Surface Focal Length G1 1 122.62 G2 4 -21.74 G3 13 41.87 G4 18 -326.91 G5 23 48.34 G6 26 78.92 G7 28 -25.48 [Variable interval data] Wide-angle end state Telephoto end state d3 2.000 51.859 d11 33.722 2.003 d17 9.826 2.000 d22 2.157 3.750 d25 2.446 6.907 d27 3.087 2.700 Bf 11.455 67.126

[0353] Figure 22A is a diagram of various aberrations when focusing on an infinite object in the wide-angle end state of the zoom optical system of the 11th embodiment, Figure 22B is a diagram of various aberrations when focusing on an infinite object in the intermediate focal length state of the zoom optical system of the 11th embodiment, and Figure 22C is a diagram of various aberrations when focusing on an infinite object in the telephoto end state of the zoom optical system of the 11th embodiment.

[0354] From each aberration diagram, it can be seen that the zoom optical system of this embodiment effectively suppresses aberration fluctuations during focusing and zooming and has high optical performance.

[0355] According to each of the above embodiments, a zoom optical system having good optical performance can be realized.

[0356] The conditional formula corresponding values of each embodiment are shown below.

[0357] f1 is the focal length of the first lens group, D1 is the thickness on the optical axis of the first lens group, and M1 is the movement amount of the first lens group during zooming from the wide-angle end state to the telephoto end state. fN1 is the focal length of the first negative lens group, fN2 is the focal length of the second negative lens group, fP1 is the focal length of the first positive lens group, and fP2 is the focal length of the second positive lens group. MP1 is the movement amount of the first positive lens group during zooming from the wide-angle end state to the telephoto end state, and MN1 is the movement amount of the first negative lens group during zooming from the wide-angle end state to the telephoto end state. fFP is the focal length of the front focusing group, and fRPw is the combined focal length in the wide-angle end state of the lens group arranged on the image side of the front focusing group. fFN is the focal length of the rear focusing group, and fRNw is the combined focal length in the wide-angle end state of the lens group arranged on the image side of the rear focusing group. fR is the focal length of the final lens group. nd1 is the refractive index of the lens in the first lens group with respect to the d-line, and νd1 is the Abbe number of the lens in the first lens group based on the d-line. r1 is the radius of curvature of the object-side lens surface of the lens arranged closest to the image side, and r2 is the radius of curvature of the image-side lens surface of the lens arranged closest to the image side. fN is the focal length of the lens group with the weakest refractive power among the lens groups having negative refractive power in the rear group, and Fnot is the F-number of the zoom optical system in the telephoto end state. Bfw is the back focus in the wide-angle end state of the zoom optical system, and fw is the focal length in the wide-angle end state of the zoom optical system. fF1 is the focal length of the first focusing group, and fF2 is the focal length of the second focusing group. νdP1 is the Abbe number of the positive lens in the rear group based on the d-line, νdN is the Abbe number of the negative lens in the rear group based on the d-line, and νdP2 is the Abbe number of the positive lens in the rear group based on the d-line.

[0358] [Condition formula corresponding value] Condition formula | Example 1st 2nd 3rd 4th 5th 6th (1) f1 / D1 : 13.049 11.997 19.776 23.460 12.316 11.866 (2) M1 / D1 : 2.757 2.946 9.731 10.557 4.959 4.745 (3) f1 / (-fN1) : 5.679 3.777 4.645 4.878 5.677 5.938 (4) f1 / (-fN2) : 2.898 1.512 2.208 2.809 3.508 2.399 (5) fN1 / fN2 : 0.510 0.400 0.475 0.576 0.618 0.404 (6) f1 / fP1 : 3.178 3.116 1.502 1.284 2.298 4.379 (7) fP1 / (-fN1) : 1.787 1.212 3.092 3.798 2.470 1.356 (8) MP1 / MN1 : 16.793 5.337 2.278 2.641 3.218 3.280 (9) fP1 / fP2 : 0.391 0.922 1.977 3.173 0.881 0.817 (10) f1 / fFP : 1.117 2.873 - 1.453 1.006 - 1.418 1.715 (11) fFP / fRPw : -1.109 -1.200 - -0.719 -1.361 - -2.043 -2.046 (12) f1 / (-fFN) : - 1.512 2.208 2.809 - 3.751 (13) (-fFN) / fRNw : - -1.171 0.474 0.215 - 0.269 (14) f1 / (-fR) : 2.898 1.770 2.094 2.457 3.508 - (15) f1 / fR : - - - - - 1.009 (16) nd1 : 1.855 1.847 1.752 1.727 1.904 1.954 1.816 1.755 1.618 1.618 (17) νd1 : 25.15 23.70 52.47 53.67 31.27 32.33 46.59 52.30 63.34 63.34 (18)(r2 - r1) / (r2 + r1): 0.337 -2.218 -1.507 -11.160 0.373 0.752 (19)fN / fFN : - 1.000 1.054 1.143 - 1.564 (20)Fnot : 2.920 4.100 4.120 4.120 4.120 4.100 (21)Bfw / fw : 0.479 0.492 0.731 0.637 0.549 0.589 (22)|fF1| / |fF2| : 1.269 0.526 - 0.517 1.705 - (23)νdP1 : 42.73 25.46 25.66 24.50 25.15 30.05 42.50 34.92 24.07 23.90 20.88 23.80 24.40 23.80 27.03 32.19 23.80 (24)νdN : 67.00 61.25 80.93 82.34 82.57 63.34 63.34 91.38 70.00 (25)νdP2 : 67.90 71.68 62.63 60.92 66.97 82.57 82.57 63.34 76.49 74.04 63.34 67.90 67.00 67.90 64.15 64.20 82.57 67.90 82.57 70.31 71.67

[0359] Conditional formula | Example No. 7th 8th 9th 10th 11th (1)f1 / D1 : 26.049 9.548 9.548 10.302 9.345 (2)M1 / D1 : 10.323 5.387 5.387 5.957 5.461 (3)f1 / (-fN1) : 5.429 6.554 6.554 5.914 5.639 (4) f1 / (-fN2) : 2.355 2.347 2.347 0.130 0.375 (5) fN1 / fN2 : 0.434 0.358 0.358 0.022 0.067 (6) f1 / fP1 : 1.608 1.855 1.855 2.771 2.929 (7) fP1 / (-fN1) : 3.376 3.532 3.532 2.134 1.926 (8) MP1 / MN1 : 3.071 2.674 2.674 1.974 2.455 (9) fP1 / fP2 : 2.670 2.198 2.198 1.082 0.866 (10) f1 / fFP : 1.744 - 4.078 - 2.537 1.554 (11) fFP / fRPw : -1.672 - -0.795 - -1.110 -3.098 (12) f1 / (-fFN) : 2.355 2.347 2.347 0.130 - 3.417 (13) (-fFN) / fRNw : 0.180 -0.343 -0.343 -23.612 - 0.112 (14) f1 / (-fR) : 2.916 0.806 0.806 - 4.813 (15) f1 / fR : - - - 0.384 - (16) nd1 : 1.610 1.603 1.603 1.750 1.903 1.593 1.593 (17) νd1 : 61.93 65.44 65.44 35.25 35.77 67.90 67.90 (18) (r2 - r1) / (r2 + r1): 1.734 1.299 1.299 0.061 -1.000 (19) fN / fFN : 1.000 2.913 2.913 1.000 - 26.324 (20) Fnot: 4.120 6.480 6.480 6.569 6.574 (21) Bfw / fw: 0.488 0.476 0.476 0.485 0.464 (22) |fF1| / |fF2|: 0.740 - 0.575 - 0.612 (23) νdP1: 25.58 20.88 20.88 27.03 23.08 26.67 35.72 35.72 35.27 23.80 42.73 42.73 45.78 23.80 23.80 31.16 37.57 37.57 (24) νdN: 81.23 - - 82.57 - 91.38 (25) νdP2: 61.07 81.49 81.49 66.92 66.92 72.77 82.57 67.90 63.96

[0360] The above examples show specific examples of the present invention, and the present invention is not limited thereto. The following content can be appropriately adopted within the range that does not impair the optical performance of the variable magnification optical system of the embodiment of the present application.

[0361] Also, an antireflection film having a high transmittance in a wide wavelength range may be applied to the lens surfaces of the lenses constituting the variable magnification optical system of each of the above examples. Thereby, flare and ghost can be reduced, and high-contrast optical performance can be achieved.

[0362] Next, a camera equipped with the variable magnification optical system of the present embodiment will be described with reference to FIG. 23. FIG. 23 is a schematic diagram of a camera equipped with the variable magnification optical system of the present embodiment.

[0363] The camera 1 is a so-called mirrorless camera with interchangeable lenses, which includes the variable magnification optical system according to the first embodiment as the photographing lens 2.

[0364] In camera 1, light from an object (subject), not shown, is condensed by photographing lens 2 and reaches imaging device 3. Imaging device 3 converts the light from the subject into image data. The image data is displayed on electronic viewfinder 4. As a result, a photographer who positions his / her eye at eye point EP can observe the subject.

[0365] Also, when a release button, not shown, is pressed by the photographer, the image data is stored in a memory, not shown. In this way, the photographer can photograph the subject with camera 1.

[0366] Here, the zoom optical system of the first embodiment mounted as photographing lens 2 in camera 1 is a zoom optical system having good optical performance. Therefore, camera 1 can realize good optical performance. Note that even if a camera is configured with the zoom optical systems of the second to eleventh embodiments mounted as photographing lens 2, the same effects as those of camera 1 can be achieved.

[0367] Finally, an outline of the manufacturing method of the zoom optical system of the present embodiment will be described with reference to FIG. 24. FIG. 24 is a flowchart showing the outline of the manufacturing method of the zoom optical system of the present embodiment.

[0368] The manufacturing method of the zoom optical system of the present embodiment shown in FIG. 24 includes the following steps S1 to S4.

[0369] Step S1: Prepare a plurality of lens groups of six or more groups including a first lens group having a positive refractive power and a rear group disposed on the image side of the first lens group.

[0370] Step S2: Make the intervals between the respective lens groups change during zooming.

[0371] Step S3: Configure the first lens group with two or fewer lenses.

[0372] Step S4: Make the zoom optical system satisfy all of the following conditional expressions. (1) 8.00 < f1 / D1 < 27.00 (2) 1.00 < M1 / D1 < 12.00 However, f1: Focal length of the first lens group D1: Thickness on the optical axis of the first lens group M1: Movement amount of the first lens group during zooming from the wide-angle end state to the telephoto end state

[0373] According to the manufacturing method of the zoom optical system of the present embodiment, a zoom optical system having good imaging performance can be manufactured.

[0374] It should be understood by those skilled in the art that various changes, substitutions, and modifications can be made to this without departing from the spirit and scope of the present invention.

Explanation of reference signs

[0375] S Aperture stop I Image plane 1 Camera 2 Photographing lens 3 Image sensor

Claims

1. a plurality of lens groups of six or more, the plurality of lens groups being composed of a first lens group having a positive refractive power and a rear lens group disposed closer to the image side than the first lens group; the rear group includes, in order from the object side, a first negative lens group having negative refractive power, a second negative lens group having negative refractive power and disposed closer to the image side than the first negative lens group, and a first positive lens group having positive refractive power, During magnification change, the intervals between the lens groups change and the first negative lens group moves, the first lens group is composed of two or less lenses, the first negative lens group has a single lens having negative refractive power closest to the object side, A variable magnification optical system that satisfies both of the following conditions: 8.00 < f1 / D1 < 27.00 1.00 < M1 / D1 < 12.00 1.25 < f1 / (-fN2) < 4.00 1.50 < fP1 / (-fN1) < 4.50 however, f1: focal length of the first lens group D1: thickness of the first lens group on the optical axis M1: the movement amount of the first lens group when changing the magnification from the wide-angle end state to the telephoto end state fN2: focal length of the second negative lens unit fP1: focal length of the first positive lens group fN1: focal length of the first negative lens unit

2. 2. The variable magnification optical system according to claim 1, which satisfies the following condition: 1.00 < f1 / (-fN1) < 8.00

3. 3. The variable magnification optical system according to claim 1, wherein the following formula is satisfied: 0.01 < fN1 / fN2 < 1.00

4. 4. The variable magnification optical system according to claim 1, which satisfies the following condition: 0.75 < f1 / fP1 < 5.00

5. 5. A variable magnification optical system according to claim 1, which satisfies the following condition: 1.00 < MP1 / MN1 < 20.00 however, MP1: the movement amount of the first positive lens unit when changing magnification from the wide-angle end state to the telephoto end state MN1: the movement amount of the first negative lens unit when changing magnification from the wide-angle end state to the telephoto end state

6. 6. The variable magnification optical system according to claim 1, wherein the rear group further comprises a second positive lens group having positive refractive power, the second positive lens group being arranged closer to the image side than the first positive lens group.

7. 7. The variable magnification optical system according to claim 6, which satisfies the following condition: 0.25 < fP1 / fP2 < 3.50 however, fP2: focal length of the second positive lens unit

8. the rear group includes a positive focusing group that has a positive refractive power and moves along the optical axis during focusing; 8. A variable magnification optical system according to claim 1, which satisfies the following condition: 0.75 < f1 / fFP < 4.50 however, fFP: focal length of the focusing group

9. the rear group includes a positive focusing group that has a positive refractive power and moves along the optical axis during focusing; 9. A variable magnification optical system according to claim 1, which satisfies the following condition: -3.50 < fFP / fRPw < -0.50 however, fFP: focal length of the focusing group fRPw: the composite focal length in the wide-angle end state of the lens group disposed on the image side of the correct focusing group

10. the rear group includes a negative focusing group having negative refractive power and moving along the optical axis during focusing; 10. A variable magnification optical system according to claim 1, which satisfies the following condition: 0.10 < f1 / (-fFN) < 4.00 however, fFN: focal length of the negative focusing group

11. the rear group includes a negative focusing group having negative refractive power and moving along the optical axis during focusing; 11. A variable magnification optical system according to claim 1, which satisfies the following condition: -25.00 < (-fFN) / fRNw < 1.00 however, fFN: focal length of the negative focusing group fRNw: the composite focal length in the wide-angle end state of the lens group disposed on the image side of the negative focusing group

12. Among the lens groups in the rear group, the final lens group arranged closest to the image side has negative refractive power, 12. A variable magnification optical system according to claim 1, which satisfies the following condition: 0.10 < f1 / (-fR) < 5.00 however, fR: focal length of the final lens group

13. Among the lens groups in the rear group, the final lens group arranged closest to the image side has positive refractive power, 12. A variable magnification optical system according to claim 1, which satisfies the following condition: 0.10 < f1 / fR < 1.50 however, fR: focal length of the final lens group

14. 14. The variable magnification optical system according to claim 1, wherein the first lens group has at least one lens that satisfies all of the following conditional expressions: 1<x<x1, 1<x2, 1<x3, 1<x4, 1<x5, 1<x6, 1<x7, 1<x8, 1<x9, 1<x10, 1<x11, 1<x12, 1<x13, 1<x 1.45 < nd1 < 2.10 20.00 < νd1 < 75.00 however, nd1: refractive index of the lens in the first lens group with respect to the d line νd1: Abbe number of the lens in the first lens group based on the d line

15. 15. A variable magnification optical system according to claim 1, wherein the lens arranged closest to the image side satisfies the following condition: -12.00 < (r2-r1) / (r2+r1) < 2.00 however, r1: radius of curvature of the object-side lens surface of the lens disposed closest to the image r2: radius of curvature of the image-side lens surface of the lens disposed closest to the image

16. the rear group includes a negative focusing group having negative refractive power and moving along the optical axis during focusing; 16. A variable magnification optical system according to claim 1, which satisfies the following condition: 0.75 < fN / fFN < 30.00 however, fN: focal length of the lens group having the weakest negative refractive power among the lens groups in the rear group fFN: focal length of the negative focusing group

17. 17. A variable magnification optical system according to claim 1, which satisfies the following condition: Fnot < 7.00 however, Fnot: F-number of the variable magnification optical system in the telephoto end state

18. 18. A variable magnification optical system according to claim 1, wherein, of the lens groups in the rear group, the lens group second from the image side is moved along the optical axis during focusing.

19. 19. A variable magnification optical system according to claim 1, which satisfies the following condition: 0.10 < Bfw / fw < 0.95 however, Bfw: back focus of the variable magnification optical system in the wide-angle end state fw: focal length of the variable magnification optical system in the wide-angle end state

20. 20. The variable magnification optical system according to claim 1, wherein the first lens group moves toward the object side when varying magnification from the wide-angle end state to the telephoto end state.

21. 21. The variable magnification optical system according to claim 1, wherein the first lens group is composed of, in order from the object side, a negative lens and a positive lens.

22. The variable magnification optical system according to any one of claims 1 to 21, wherein the first lens group is made up of a positive lens.

23. 23. A variable power optical system according to claim 1, wherein the rear group comprises a first focusing group and a second focusing group each of which moves along the optical axis during focusing.

24. 24. The variable magnification optical system according to claim 23, which satisfies the following condition: 0.20 < | fF1 | / | fF2 | < 30.00 however, fF1: focal length of the first focusing group fF2: focal length of the second focusing group

25. 25. The variable magnification optical system according to claim 1, wherein at least one of the positive lenses in the rear group satisfies the following first dispersion condition: ##EQU1## νdP1 < 45.00 however, νdP1: Abbe number of the positive lens in the rear group based on the d line

26. 26. The variable magnification optical system according to claim 25, wherein the positive lens satisfying the first dispersion condition is included in a negative lens group having negative refractive power among the lens groups in the rear group.

27. 27. The variable magnification optical system according to claim 1, wherein at least one of the negative lenses in the rear group satisfies the following second dispersion condition: ##EQU1## 60.00 < vdN however, νdN: Abbe number of the negative lens in the rear group based on the d line

28. 28. The variable magnification optical system according to claim 27, wherein the negative lens satisfying the second dispersion condition is included in a final lens group that is disposed closest to the image side among the lens groups in the rear group.

29. 29. The variable magnification optical system according to claim 1, wherein at least one of the lens groups in the rear group having positive refractive power has a positive lens that satisfies the following third dispersion condition: ##EQU1## 60.00 < νdP2 however, νdP2: Abbe number of the positive lens in the rear group based on the d line

30. An optical instrument comprising a variable magnification optical system according to any one of claims 1 to 29.

31. A method for manufacturing a variable magnification optical system having six or more lens groups, the lens groups being composed of a first lens group having positive refractive power and a rear group disposed closer to an image side than the first lens group, comprising: the rear group includes, in order from the object side, a first negative lens group having negative refractive power, a second negative lens group having negative refractive power and disposed closer to the image side than the first negative lens group, and a first positive lens group having positive refractive power, During magnification change, the intervals between the lens groups change and the first negative lens group moves, the first lens group is composed of two or less lenses, the first negative lens group has a single lens having negative refractive power closest to the object side, A manufacturing method for a variable magnification optical system in which the lenses are arranged so as to satisfy both of the following conditional expressions: 8.00 < f1 / D1 < 27.00 1.00 < M1 / D1 < 12.00 1.25 < f1 / (-fN2) < 4.00 1.50 < fP1 / (-fN1) < 4.50 however, f1: focal length of the first lens group D1: thickness of the first lens group on the optical axis M1: the amount of movement of the first lens group when changing magnification from the wide-angle end state to the telephoto end state fN2: focal length of the second negative lens unit fP1: focal length of the first positive lens group fN1: focal length of the first negative lens unit

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