Variable power optical system and imaging device

Abstract

To provide a variable power optical system which is structured in a compact size, whose F number is small in the entire variable power range, and which holds good optical performance in the entire variable power range, and an imaging device that is equipped with the variable power optical system.SOLUTION: The variable power optical system comprises a front group, an intermediate group, and a rear group in order from the object side. The front group is composed of two or less lens groups having positive refractive power. The intermediate group is composed of two or less lens groups having negative refractive power. The rear group is composed of a plurality of lens groups. The lens group of the rear group that is most object side has positive refractive power. During variable power, the lens group of the front group that is most object side moves and all intervals in the adjacent lens groups change. The variable power optical system satisfies a predetermined conditional expression.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The technology of the present disclosure relates to a variable magnification optical system and an imaging apparatus. [Background technology]

[0002] 2. Description of the Related Art Conventionally, a variable magnification optical system that can be used in an imaging device such as a digital camera is disclosed in Japanese Patent Application Laid-Open No. 2003-233696. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2022-028060 Summary of the Invention [Problem to be solved by the invention]

[0004] There is a demand for variable magnification optical systems that are compact, have a small F-number over the entire range of magnification, and maintain good optical performance over the entire range of magnification. These demands are becoming higher every year.

[0005] The present disclosure provides a variable magnification optical system that is compact, has a small F-number over the entire range of magnification change, and maintains good optical performance over the entire range of magnification change, and an imaging device that includes this variable magnification optical system. [Means for solving the problem]

[0006] A first aspect of the present disclosure is a variable magnification optical system comprising, in order from the object side to the image side, a front group, an intermediate group, and a rear group, the front group consisting of two or less lens groups having positive refractive power, the intermediate group consisting of two or less lens groups having negative refractive power, the rear group consisting of a plurality of lens groups, the lens group closest to the object in the rear group having positive refractive power, and during magnification variation, the lens group closest to the object in the front group moves and all of the intervals between adjacent lens groups change; 5 <TLw / (fw×tanωw)<12 (1) 0.5 <Bfw / (fw×tanωw)<2.5 (2) 1.8 <Fnot×(TLt / ft)<5 (3) The conditional expressions (1), (2), and (3) expressed by the following formulae are satisfied. The symbols in conditional expressions (1), (2), and (3) are defined as follows. When an object at infinity is focused on at the wide-angle end, the sum of the distance on the optical axis from the lens surface of the front group closest to the object to the lens surface of the rear group closest to the image, and the back focus in the air-equivalent distance of the entire system is defined as TLw. When an object at infinity is focused on at the wide-angle end, the focal length of the entire system is defined as fw. When an object at infinity is focused on at the wide-angle end, the maximum half angle of view is defined as ωw. When an object at infinity is focused on at the wide-angle end, the back focus in the air-equivalent distance of the entire system is defined as Bfw. When an object at infinity is focused on at the telephoto end, the maximum F-number is defined as Fnot. When an object at infinity is focused on at the telephoto end, the sum of the distance on the optical axis from the lens surface of the front group closest to the object to the lens surface of the rear group closest to the image, and the back focus in the air-equivalent distance of the entire system is defined as TLt. The focal length of the entire system when focused on an object at infinity at the telephoto end is ft.

[0007] A second aspect of the present disclosure provides a variable magnification optical system according to the first aspect, 1.9 <Fnot×(TLt / ft)<4.6 (3-1) The condition (3-1) is satisfied.

[0008] A third aspect of the present disclosure provides a variable magnification optical system according to the second aspect, 2 <Fnot×(TLt / ft)<4.3 (3-2) The condition (3-2) is satisfied.

[0009] A fourth aspect of the present disclosure is a variable magnification optical system according to the third aspect, 2.2 <Fnot×(TLt / ft)<4 (3-3) The condition (3-3) is satisfied.

[0010] A fifth aspect of the present disclosure provides a variable magnification optical system according to the first aspect, 0.34<(fw×TLw×Fnot) / ft 2 <0.97 (4) The condition (4) is satisfied.

[0011] A sixth aspect of the present disclosure is a variable magnification optical system according to the fifth aspect, 0.36<(fw×TLw×Fnot) / ft 2 <0.92 (4-1) The condition (4-1) is satisfied.

[0012] A seventh aspect of the present disclosure is a variable magnification optical system according to the sixth aspect, 0.38<(fw×TLw×Fnot) / ft 2 <0.87 (4-2) The condition (4-2) is satisfied.

[0013] An eighth aspect of the present disclosure is a variable magnification optical system according to the seventh aspect, 0.41<(fw×TLw×Fnot) / ft 2 <0.8 (4-3) The condition (4-3) is satisfied.

[0014] A ninth aspect of the present disclosure is a variable magnification optical system according to the first aspect, in which, when the maximum aperture F-number in a state in which the lens is focused on an object at infinity at the wide-angle end is Fnow, 0.075 <tanωw / Fnow<0.3 (5) The condition (5) is satisfied.

[0015] A tenth aspect of the present disclosure is the variable magnification optical system of the ninth aspect, 0.092 <tanωw / Fnow<0.27 (5-1) The condition (5-1) is satisfied.

[0016] An eleventh aspect of the present disclosure is a variable power optical system according to the tenth aspect, 0.105 <tanωw / Fnow<0.25 (5-2) The condition (5-2) is satisfied.

[0017] A twelfth aspect of the present disclosure is a variable power optical system according to the first aspect, 1.1 <TLt / TLw<1.9 (6) Condition (6) expressed by the following formula (6) is satisfied.

[0018] A thirteenth aspect of the present disclosure is a variable power optical system according to the twelfth aspect, 1.15 <TLt / TLw<1.48 (6-1) The condition (6-1) is satisfied.

[0019] A fourteenth aspect of the present disclosure is a variable power optical system according to the twelfth aspect, 2.2 <Fnot×(TLt / ft)<4 (3-3) The condition (3-3) is satisfied.

[0020] A fifteenth aspect of the present disclosure is a variable power optical system according to the fourteenth aspect, 0.41<(fw×TLw×Fnot) / ft 2 <0.8 (4-3) The condition (4-3) is satisfied.

[0021] A sixteenth aspect of the present disclosure is a variable power optical system according to the fifteenth aspect, 0.105 <tanωw / Fnow<0.25 (5-2) The condition (5-2) is satisfied.

[0022] A seventeenth aspect of the present disclosure is a variable power optical system according to the third aspect, in which, when the focal length of the front group when focused on an object at infinity at the wide-angle end is fFw, and the focal length of the middle group when focused on an object at infinity at the wide-angle end is fMw, 0.8 <fFw / (-fMw)<8 (7) Condition (7) expressed by the following formula (7) is satisfied.

[0023] An eighteenth aspect of the present disclosure is a variable power optical system according to the seventeenth aspect, 1.1 <fFw / (-fMw)<5.3 (7-1) The condition (7-1) is satisfied.

[0024] A nineteenth aspect of the present disclosure is a variable power optical system according to the eighteenth aspect, 0.8 <TLw / ft<1.5 (8) The condition (8) is satisfied.

[0025] A twentieth aspect of the present disclosure is a variable power optical system according to the nineteenth aspect, 1.15 <TLt / TLw<1.48 (6-1) The condition (6-1) is satisfied.

[0026] A twenty-first aspect of the present disclosure is a variable power optical system according to the twentieth aspect, 0.38<(fw×TLw×Fnot) / ft 2 <0.87 (4-2) The condition (4-2) is satisfied.

[0027] A twenty-second aspect of the present disclosure is a variable power optical system according to the twenty-first aspect, 0.092 <tanωw / Fnow<0.27 (5-1) The condition (5-1) is satisfied.

[0028] A twenty-third aspect of the present disclosure is a variable magnification optical system according to the second aspect, 0.36<(fw×TLw×Fnot) / ft 2 <0.92 (4-1) The condition (4-1) is satisfied.

[0029] A twenty-fourth aspect of the present disclosure is a variable power optical system according to the twenty-third aspect, 0.092 <tanωw / Fnow<0.27 (5-1) The condition (5-1) is satisfied.

[0030] A twenty-fifth aspect of the present disclosure is a variable power optical system according to the twenty-third aspect, 0.105 <tanωw / Fnow<0.25 (5-2) The condition (5-2) is satisfied.

[0031] A 26th aspect of the present disclosure is a variable power optical system according to the 25th aspect, wherein the rear group includes an Lp1 lens having positive refractive power, and an Ln1 lens having negative refractive power and disposed adjacent to the image side of the Lp1 lens. The image side surface of the Lp1 lens is aspheric in shape in which the refractive power at the position of the maximum effective diameter is shifted in the negative direction compared to the refractive power in the paraxial region. The object side surface of the Ln1 lens is aspheric in shape in which the refractive power at the position of the maximum effective diameter is shifted in the positive direction compared to the refractive power in the paraxial region.

[0032] A 27th aspect of the present disclosure is a variable power optical system according to the 24th aspect, wherein the rear group includes an Ln2 lens having negative refractive power and an Lp2 lens having positive refractive power and disposed adjacent to the image side of the Ln2 lens. The object side surface of the Ln2 lens is aspheric in shape in which the refractive power at the position of the maximum effective diameter is shifted in the negative direction compared to the refractive power in the paraxial region. The image side surface of the Ln2 lens is aspheric in shape in which the refractive power at the position of the maximum effective diameter is shifted in the positive direction compared to the refractive power in the paraxial region.

[0033] A twenty-eighth aspect of the present disclosure is a variable power optical system according to the first aspect, 2.1 <ft / fw<6 (9) Condition (9) expressed by the following formula (9) is satisfied.

[0034] A 29th aspect of the present disclosure is a variable power optical system according to the first aspect, in which, when the focal length of the lens group closest to the object side in the front group is fF1, 1.5 <fF1 / fw<12 (10) Condition (10) expressed by the following formula is satisfied.

[0035] A 30th aspect of the present disclosure is a variable power optical system according to the first aspect, in which, assuming that the focal length of the lens group closest to the object side in the front group is fF1 and the focal length of the middle group when focused on an object at infinity at the wide-angle end is fMw, 2 <fF1 / (-fMw)<13 (11) satisfies conditional expression (11) expressed by:

[0036] A thirty-first aspect of the present disclosure is a variable power optical system according to the first aspect, in which, when the focal length of the lens group closest to the object side in the front group is fF1, 0.7 <fF1 / (fw×ft) 1 / 2 <4.7 (12) The condition (12) is satisfied.

[0037] A thirty-second aspect of the present disclosure is a variable power optical system according to the first aspect, wherein, when the focal length of the middle group at the wide-angle end is focused on an object at infinity, fMw is: 0.18<(-fMw) / (fw×ft) 1 / 2 <0.8 (13) The condition (13) is satisfied.

[0038] A thirty-third aspect of the present disclosure provides a variable power optical system according to the fifth aspect, in which, when the focal length of the lens group closest to the object side in the front group is fF1, 1.3 <fF1 / (ft / Fnot)<8 (14) The condition (14) is satisfied.

[0039] A thirty-fourth aspect of the present disclosure is the variable magnification optical system of the thirty-third aspect, 1.75 <fF1 / (ft / Fnot)<2.7 (14-1) The condition (14-1) expressed by the following formula is satisfied.

[0040] A thirty-fifth aspect of the present disclosure is the variable magnification optical system of the thirty-fourth aspect, 0.75 <Bfw / (fw×tanωw)<1.84 (2-1) The condition (2-1) is satisfied.

[0041] A thirty-sixth aspect of the present disclosure is a variable power optical system according to the thirty-fifth aspect, 0.092 <tanωw / Fnow<0.27 (5-1) The condition (5-1) is satisfied.

[0042] A thirty-seventh aspect of the present disclosure is the variable magnification optical system of the thirty-sixth aspect, 1.1 <TLt / TLw<1.9 (6) Condition (6) expressed by the following formula (6) is satisfied.

[0043] A thirty-eighth aspect of the present disclosure is the variable magnification optical system of the thirty-seventh aspect, 0.8 <TLw / ft<1.5 (8) The condition (8) is satisfied.

[0044] A thirty-ninth aspect of the present disclosure is a variable magnification optical system according to the first aspect, wherein the variable magnification optical system includes an aperture stop on the image side of the lens surface of the intermediate group closest to the image side, and when focused on an object at infinity at the wide-angle end, the distance on the optical axis from the lens surface of the front group closest to the object side to the aperture stop is DDL1STw, and the focal length of the lens group closest to the object side in the front group is fF1, 0.1 <DDL1STw / fF1<0.9 (15) The condition (15) is satisfied.

[0045] A fortieth aspect of the present disclosure is a variable magnification optical system according to the first aspect, wherein the variable magnification optical system includes an aperture stop, and when the distance on the optical axis from the lens surface of the front group closest to the object to the aperture stop in a state focused on an object at infinity at the wide-angle end is DDL1STw, 0.18 <DDL1STw / TLw<0.75 (16) Satisfies condition (16) expressed by:

[0046] A forty-first aspect of the present disclosure is a variable power optical system according to the first aspect, in which, when the focal length of the rear group at the wide-angle end is focused on an object at infinity, fRw is: 0.7 <fw / fRw<3 (17) Satisfies condition (17) expressed by:

[0047] A forty-second aspect of the present disclosure is a variable power optical system according to the first aspect, wherein, when the focal length of the rear group at the telephoto end is focused on an object at infinity, fRt is: 1.1 <ft / fRt<7 (18) Condition (18) expressed by the following formula is satisfied.

[0048] A forty-third aspect of the present disclosure is a variable power optical system according to the first aspect, in which, when the focal length of the lens unit closest to the object side in the rear group is fR1, 0.05 <fR1 / (fw×ft) 1 / 2 <3 (19) satisfies conditional expression (19) expressed by:

[0049] A forty-fourth aspect of the present disclosure is a variable power optical system according to the first aspect, in which, when the focal length of the lens unit in the rear group closest to the object side is fR1, 0.05 <fw / fR1<2.5 (20) Satisfies condition (20) expressed by:

[0050] A forty-fifth aspect of the present disclosure is such that, in the variable power optical system of the first aspect, at least one lens group that does not move during variable power is disposed between the front group and the lens group in the rear group that is closest to the image side.

[0051] A 46th aspect of the present disclosure is a variable magnification optical system according to the first aspect, further comprising: a vibration reduction group that moves in a direction intersecting the optical axis during image blur correction, and is disposed on the image side of the front group; If the focal length of the vibration isolation group is fIS, 0.07<|fIS / ft|<0.5 (21) The condition (21) is satisfied.

[0052] A forty-seventh aspect of the present disclosure is the variable magnification optical system of the forty-sixth aspect, wherein the vibration reduction group is disposed in the intermediate group.

[0053] A forty-eighth aspect of the present disclosure is such that, in the variable power optical system of the first aspect, a focusing group that moves along the optical axis during focusing is disposed only in the rear group.

[0054] A forty-ninth aspect of the present disclosure is the variable power optical system of the forty-eighth aspect, wherein two focusing groups are disposed in the rear group.

[0055] A fiftieth aspect of the present disclosure is a variable power optical system according to the first aspect, wherein the front group includes a cemented lens in which a negative meniscus lens with a convex surface facing the object side and a positive lens with a convex surface facing the object side are cemented together in this order from the object side, and where the refractive index of the negative meniscus lens with respect to the d-line is Ndn and the Abbe number of the negative meniscus lens with reference to the d-line is νdn, 1.94 <Ndn+0.01×νdn<2.5 (22) The condition (22) is satisfied.

[0056] A fifty-first aspect of the present disclosure provides, in the variable power optical system of the fifty-first aspect, when the refractive index of the positive lens with respect to the d-line is Ndp and the Abbe number of the positive lens with respect to the d-line is νdp, 2 <Ndp+0.01×νdp<2.6 (23) The condition (23) is satisfied.

[0057] A fifty-second aspect of the present disclosure provides a variable power optical system according to the first aspect, where the average value of the Abbe numbers of all the positive lenses in the front group based on the d-line is νdFp_ave, 55<νdFp_ave<95 (24) Condition (24) expressed by the following formula is satisfied.

[0058] A fifty-third aspect of the present disclosure is a variable power optical system according to the first aspect, in which, assuming that the thickness on the optical axis of the lens unit closest to the object in the front group is dF1 and the focal length of the lens unit closest to the object in the front group is fF1, 0.03 <dF1 / fF1<0.35 (25) Satisfies condition (25) expressed by:

[0059] A fifty-fourth aspect of the present disclosure is a variable power optical system according to the first aspect, in which, when the average value of the specific gravities of all the lenses in the front group is taken as GFave, 2 <GFave<4.3 (26) Condition (26) expressed by the following formula is satisfied.

[0060] A 55th aspect of the present disclosure is a variable magnification optical system of the first aspect, in which the rear group consists, in order from the object side to the image side, of a first subsequent lens group having positive refractive power, a second subsequent lens group having negative refractive power, and a third subsequent lens group having positive refractive power.

[0061] A fifty-sixth aspect of the present disclosure provides a variable power optical system according to the fifty-fifth aspect, wherein, assuming that the focal length of the first subsequent lens group is fR1 and the focal length of the third subsequent lens group is fR3, 0.05 <fR1 / fR3<0.6 (27) Condition (27) expressed by the following formula is satisfied.

[0062] A fifty-seventh aspect of the present disclosure is a variable power optical system according to the fifty-fifth aspect, wherein, assuming that the focal length of the first subsequent lens group is fR1 and the focal length of the second subsequent lens group is fR2, 0.2 <fR1 / (-fR2)<1 (28) Satisfies condition (28) expressed by:

[0063] A 58th aspect of the present disclosure is a variable magnification optical system of the first aspect, in which the rear group consists, in order from the object side to the image side, of a first subsequent lens group having positive refractive power, a second subsequent lens group having positive refractive power, and a third subsequent lens group having negative refractive power.

[0064] A fifty-ninth aspect of the present disclosure is a variable power optical system according to the fifty-eighth aspect, wherein, assuming that the focal length of the first subsequent lens group is fR1 and the focal length of the third subsequent lens group is fR3, 0.5 <fR1 / (-fR3)<1.6 (29) Condition (29) expressed by the following formula is satisfied.

[0065] A 60th aspect of the present disclosure provides, in the variable power optical system of the 58th aspect, when the focal length of the second subsequent lens group is fR2 and the focal length of the third subsequent lens group is fR3, 0.8 <fR2 / (-fR3)<3 (30) Satisfies condition (30) expressed by:

[0066] A 61st aspect of the present disclosure is that in the variable magnification optical system of the first aspect, the rear group includes, in order from the object side to the image side, at least a first subsequent lens group having positive refractive power, a second subsequent lens group having positive refractive power, a third subsequent lens group having negative refractive power, and a fourth subsequent lens group having positive refractive power.

[0067] A 62nd aspect of the present disclosure provides a variable power optical system according to the 61st aspect, where the focal length of the first subsequent lens group is fR1 and the focal length of the third subsequent lens group is fR3, 0.9 <fR1 / (-fR3)<10 (29A) satisfies condition (29A) expressed by:

[0068] A 63rd aspect of the present disclosure is a variable power optical system according to the 61st aspect, wherein, when the focal length of the second subsequent lens group is fR2 and the focal length of the third subsequent lens group is fR3, 0.1 <fR2 / (-fR3)<1.8 (30A) Condition (30A) expressed by the following formula is satisfied.

[0069] A 64th aspect of the present disclosure is a variable power optical system according to the 61st aspect, wherein, assuming that the focal length of the first subsequent lens group is fR1 and the focal length of the second subsequent lens group is fR2, 1.2 <fR1 / fR2<11 (31) satisfies condition (31) expressed by:

[0070] A 65th aspect of the present disclosure is, in the variable power optical system of the 61st aspect, when the focal length of the second subsequent lens group is fR2 and the focal length of the fourth subsequent lens group is fR4, 0.1 <fR2 / fR4<1.5 (32) Satisfies condition (32) expressed by:

[0071] A 66th aspect of the present disclosure is that in the variable magnification optical system of the first aspect, the rear group includes, in order from the object side to the image side, at least a first subsequent lens group having positive refractive power, a second subsequent lens group having negative refractive power, a third subsequent lens group having positive refractive power, and a fourth subsequent lens group having negative refractive power.

[0072] A 67th aspect of the present disclosure is a variable power optical system according to the 66th aspect, wherein, when the focal length of the first subsequent lens group is fR1 and the focal length of the third subsequent lens group is fR3, 0.25 <fR1 / fR3<6 (27A) satisfies condition (27A) expressed by:

[0073] A 68th aspect of the present disclosure is a variable power optical system according to the 66th aspect, wherein, when the focal length of the second subsequent lens group is fR2 and the focal length of the fourth subsequent lens group is fR4, 0.4 <fR2 / fR4<18 (32A) satisfies condition (32A) expressed by:

[0074] A 69th aspect of the present disclosure is a variable magnification optical system of the 66th aspect, in which the rear group consists, in order from the object side to the image side, of a first subsequent lens group having positive refractive power, a second subsequent lens group having negative refractive power, a third subsequent lens group having positive refractive power, a fourth subsequent lens group having negative refractive power, a fifth subsequent lens group having positive refractive power, and a sixth subsequent lens group having negative refractive power.

[0075] A seventieth aspect of the present disclosure provides, in the variable power optical system of the sixty-ninth aspect, when the focal length of the third subsequent lens group is fR3 and the focal length of the fifth subsequent lens group is fR5, 0.2 <fR3 / fR5<2.5 (33) Satisfies condition (33) expressed by:

[0076] A 71st aspect of the present disclosure provides, in the variable power optical system of the 69th aspect, when the focal length of the fourth subsequent lens group is fR4 and the focal length of the sixth subsequent lens group is fR6, 0.04 <fR4 / fR6<4 (34) Condition (34) expressed by the following formula is satisfied.

[0077] A 72nd aspect of the present disclosure is such that, in the variable magnification optical system of the first aspect, the rear group includes, in order from the most object side to the image side, at least a first subsequent lens group having positive refractive power, a second subsequent lens group having positive refractive power, a third subsequent lens group having positive refractive power, and a fourth subsequent lens group having negative refractive power.

[0078] A 73rd aspect of the present disclosure provides a variable power optical system according to the 72nd aspect, where the focal length of the first subsequent lens group is fR1 and the focal length of the second subsequent lens group is fR2, 0.06 <fR1 / fR2<0.7 (31A) satisfies condition (31A) expressed by:

[0079] A 74th aspect of the present disclosure provides, in the variable power optical system of the 72nd aspect, when the focal length of the second subsequent lens group is fR2 and the focal length of the third subsequent lens group is fR3, 0.5 <fR2 / fR3<11 (35) Satisfies condition (35) expressed by:

[0080] A 75th aspect of the present disclosure provides, in the variable power optical system of the 72nd aspect, when the focal length of the third subsequent lens group is fR3 and the focal length of the fourth subsequent lens group is fR4, 0.2 <fR3 / (-fR4)<3 (36) Satisfies condition (36) expressed by:

[0081] A 76th aspect of the present disclosure is a variable magnification optical system of the first aspect, in which the rear group consists, in order from the object side to the image side, of a first subsequent lens group having positive refractive power, a second subsequent lens group having positive refractive power, a third subsequent lens group having negative refractive power, and a fourth subsequent lens group having negative refractive power.

[0082] A 77th aspect of the present disclosure is a variable power optical system according to the 76th aspect, wherein, assuming that the focal length of the first subsequent lens group is fR1 and the focal length of the second subsequent lens group is fR2, 0.6 <fR1 / fR2<4 (31B) satisfies condition (31B) expressed by:

[0083] A 78th aspect of the present disclosure provides, in the variable power optical system of the 76th aspect, when the focal length of the third subsequent lens group is fR3 and the focal length of the fourth subsequent lens group is fR4, 0.05 <fR3 / fR4<1 (37) Condition (37) expressed by the following formula is satisfied.

[0084] A 79th aspect of the present disclosure is that in the variable magnification optical system of the first aspect, the rear group includes, in order from the object side to the image side, at least a first subsequent lens group having positive refractive power, a second subsequent lens group having negative refractive power, and a third subsequent lens group having negative refractive power.

[0085] An 80th aspect of the present disclosure provides, in the variable power optical system of the 79th aspect, when the focal length of the first subsequent lens group is fR1 and the focal length of the second subsequent lens group is fR2, 0.2 <fR1 / (-fR2)<1 (28A) Condition (28A) expressed by the following formula is satisfied.

[0086] An 81st aspect of the present disclosure provides, in the variable power optical system of the 79th aspect, when the focal length of the second subsequent lens group is fR2 and the focal length of the third subsequent lens group is fR3, 0.2 <fR2 / fR3<1 (35A) Condition (35A) expressed by the following formula is satisfied.

[0087] An 82nd aspect of the present disclosure is an imaging device including the variable magnification optical system according to any one of the first to 81st aspects.

[0088] In addition, in this specification, "consisting of" and "consisting of" are intended to mean that, in addition to the listed components, the following may be included: a lens that has substantially no refractive power, optical elements other than lenses such as an aperture, a filter, and a cover glass, and mechanical parts such as a lens flange, a lens barrel, an image sensor, and an image stabilization mechanism.

[0089] In this specification, "a group having positive refractive power" and "a group having positive refractive power" mean that the group as a whole has positive refractive power. Similarly, "a group having negative refractive power" means that the group as a whole has negative refractive power. "A lens having positive refractive power" and "a positive lens" are synonymous. "A lens having negative refractive power" and "a negative lens" are synonymous. In this specification, the "group" is not limited to a configuration consisting of multiple lenses, and may be a configuration consisting of only one lens.

[0090] A compound aspherical lens (a lens in which a lens (e.g. a spherical lens) and an aspherical film formed on the lens are integrally constructed and function as a single aspherical lens as a whole) is not considered a cemented lens, but is treated as a single lens. The sign of the refractive power and the surface shape of lenses including aspheric surfaces are those in the paraxial region, unless otherwise specified.

[0091] In this specification, "whole system" means a variable magnification optical system. The "focal length" used in the conditional expressions is a paraxial focal length. The "distance on the optical axis" used in the conditional expressions is a geometric distance unless otherwise specified. The values ​​used in the conditional expressions are values ​​based on the d-line when focused on an object at infinity, unless otherwise specified. Effect of the Invention

[0092] According to the present disclosure, it is possible to provide a variable magnification optical system that is compact, has a small F-number over the entire range of magnification, and maintains good optical performance over the entire range of magnification, and an imaging device equipped with this variable magnification optical system. [Brief description of the drawings]

[0093] [Figure 1] 1A and 1B correspond to the variable magnification optical system of Example 1, and are diagrams showing a cross-sectional view of the configuration of a variable magnification optical system according to one embodiment and a movement locus. [Diagram 2] FIG. 13 is a diagram for explaining symbols in a conditional expression. [Diagram 3] FIG. 4 is a diagram for explaining the position of the maximum effective diameter. [Figure 4] 3A to 3C are diagrams showing various aberrations in the variable magnification optical system of Example 1. [Diagram 5] 11A and 11B are diagrams showing a cross-sectional view and a movement locus of a variable magnification optical system according to a second embodiment. [Figure 6] 6A to 6C are diagrams showing various aberrations in the variable magnification optical system of Example 2. [Figure 7] 11A and 11B are diagrams showing a cross-sectional view and a movement locus of a variable magnification optical system according to a third embodiment. [Figure 8] 11A to 11C are diagrams showing various aberrations in the variable magnification optical system of Example 3. [Figure 9] 13A and 13B are diagrams showing a cross-sectional view and a movement locus of a variable magnification optical system according to a fourth embodiment. [Figure 10] 11A to 11C are diagrams showing various aberrations in the variable magnification optical system of Example 4. [Figure 11] 13A and 13B are diagrams showing a cross-sectional view and a movement locus of a variable magnification optical system according to a fifth embodiment. [Figure 12] 13A to 13C are diagrams showing various aberrations in the variable magnification optical system of Example 5. [Figure 13] 13A and 13B are diagrams showing a cross-sectional view and a movement locus of a variable magnification optical system according to a sixth embodiment. [Figure 14] 13A to 13C are diagrams showing various aberrations in the variable magnification optical system of Example 6. [Figure 15] 13A and 13B are diagrams showing a cross-sectional view and a movement locus of a variable magnification optical system according to a seventh embodiment. [Figure 16] 13A to 13C are diagrams showing various aberrations in the variable magnification optical system of Example 7. [Figure 17] 13A and 13B are diagrams showing a cross-sectional view and a movement locus of a variable magnification optical system according to an eighth embodiment. [Figure 18] 13A to 13C are diagrams showing various aberrations in the variable magnification optical system of Example 8. [Figure 19] 13A and 13B are diagrams showing a cross-sectional view and a movement locus of a variable magnification optical system according to a ninth embodiment. [Figure 20]13A to 13C are diagrams showing various aberrations in the variable magnification optical system of Example 9. [Figure 21] 13A and 13B are diagrams showing a cross-sectional view and a movement locus of a variable magnification optical system according to a tenth embodiment. [Figure 22] 23A to 23C are diagrams showing various aberrations in the variable magnification optical system of Example 10. [Figure 23] 13A and 13B are diagrams showing a cross-sectional view and a movement locus of a variable magnification optical system according to an eleventh embodiment. [Figure 24] 13A to 13C are diagrams showing various aberrations in the variable magnification optical system of Example 11. [Diagram 25] 13A and 13B are diagrams showing a cross-sectional view and a movement locus of a variable magnification optical system according to a twelfth embodiment. [Figure 26] 16A to 16C are diagrams showing various aberrations in the variable magnification optical system of Example 12. [Figure 27] 13A and 13B are diagrams showing a cross-sectional view and a movement locus of a variable magnification optical system according to a thirteenth embodiment. [Figure 28] 23A to 23C are diagrams showing various aberrations in the variable magnification optical system of Example 13. [Figure 29] 13A and 13B are diagrams showing a cross-sectional view and a movement locus of a variable magnification optical system according to a fourteenth embodiment. [Diagram 30] 23A to 23C are diagrams showing various aberrations in the variable magnification optical system of Example 14. [Diagram 31] 15A and 15B are diagrams showing a cross-sectional view and a movement locus of a variable magnification optical system according to a fifteenth embodiment. [Diagram 32] 23A to 23C are diagrams showing various aberrations in the variable magnification optical system of Example 15. [Diagram 33] 23A and 23B are diagrams showing a cross-sectional view and a movement locus of the variable magnification optical system of Example 16. [Diagram 34] 23A to 23C are diagrams showing various aberrations in the variable magnification optical system of Example 16. [Diagram 35] 23A and 23B are diagrams showing a cross-sectional view and a movement locus of the variable magnification optical system of Example 17. [Diagram 36] 21A to 21C are diagrams showing various aberrations in the variable magnification optical system of Example 17. [Figure 37] 23A and 23B are diagrams showing a cross-sectional view and a movement locus of the variable magnification optical system of Example 18. [Figure 38] 23A to 23C are diagrams showing various aberrations in the variable magnification optical system of Example 18. [Figure 39]23A and 23B are diagrams showing a cross-sectional view and a movement locus of the variable magnification optical system of Example 19. [Diagram 40] 23A to 23C are diagrams showing various aberrations in the variable magnification optical system of Example 19. [Diagram 41] 23A and 23B are diagrams showing a cross-sectional view and a movement locus of the variable magnification optical system according to the twentieth embodiment. [Diagram 42] 23A to 23C are diagrams showing various aberrations in the variable magnification optical system of Example 20. [Diagram 43] 23A and 23B are diagrams showing a cross-sectional view and a movement locus of the variable magnification optical system of Example 21. [Diagram 44] 23A to 23C are diagrams showing various aberrations in the variable magnification optical system of Example 21. [Diagram 45] 23A and 23B are diagrams showing a cross-sectional view and a movement locus of the variable magnification optical system of Example 22. [Diagram 46] 23A to 23C are diagrams showing various aberrations in the variable magnification optical system of Example 22. [Figure 47] 23A and 23B are diagrams showing a cross-sectional view and a movement locus of the variable magnification optical system of Example 23. [Figure 48] 23A to 23C are diagrams showing various aberrations in the variable magnification optical system of Example 23. [Figure 49] 23A and 23B are diagrams showing a cross-sectional view and a movement locus of the variable magnification optical system of Example 24. [Figure 50] 23A to 23C are diagrams showing various aberrations in the variable magnification optical system of Example 24. [Figure 51] 1 is a perspective view of the front side of an imaging device according to an embodiment. [Figure 52] FIG. 2 is a perspective view of the rear side of the imaging device according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0094] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0095] FIG. 1 shows a cross-sectional view and a movement trajectory of a variable magnification optical system according to an embodiment of the present disclosure. In FIG. 1, the upper row labeled "Wide" shows the wide-angle end state, and the lower row labeled "Tele" shows the telephoto end state. The example shown in FIG. 1 corresponds to the variable magnification optical system of Example 1 described later. FIG. 1 shows a state in which the lens is focused on an object at infinity, with the left side being the object side and the right side being the image side. FIG. 1 also shows the axial light beam and the light beam of the maximum half angle of view ωw at the wide-angle end, and the axial light beam and the light beam of the maximum half angle of view ωw at the telephoto end.

[0096] The variable magnification optical system of the present disclosure comprises, in order from the object side to the image side along the optical axis Z, a front group GF, an intermediate group GM, and a rear group GR. The front group GF comprises two or less lens groups having positive refractive power. The intermediate group comprises two or less lens groups having negative refractive power. The rear group GR comprises a plurality of lens groups. The lens group closest to the object in the rear group GR has positive refractive power. When varying magnification, the lens group closest to the object in the front group GF moves, and all of the intervals between adjacent lens groups in the variable magnification optical system change. The above configuration is advantageous in suppressing various aberrations throughout the entire range of magnification variation.

[0097] In particular, by making the front group GF a group having positive refractive power, the total optical length can be shortened, which is advantageous for achieving both compactness and a high zoom ratio. Also, by making the front group GF a group having positive refractive power, the height of the light beam incident on the middle group GM from the optical axis Z can be reduced, which is advantageous for suppressing aberration fluctuations during zooming. By configuring the front group GF to be composed of one or two lens groups having positive refractive power and configuring the middle group GM to be composed of one or two lens groups having negative refractive power, it is advantageous for performing zooming while suppressing various aberrations. By changing the spacing between the multiple groups during zooming, it is advantageous for suppressing various aberrations throughout the entire zoom range.

[0098] In this specification, a group whose distance in the optical axis direction between adjacent groups changes during magnification is defined as one lens group. During magnification, the distance between adjacent lenses in one lens group does not change. That is, a "lens group" is a component of a variable magnification optical system, and is a part including at least one lens separated by an air gap that changes during magnification. During magnification, each lens group moves or remains stationary. Note that "not moving during magnification" means that the lens group is fixed with respect to the image plane Sim during magnification. The "lens group" may include components other than lenses that do not have refractive power, such as an aperture stop St.

[0099] As an example, each group of the variable magnification optical system shown in FIG. 1 is configured as follows. The front group GF is made up of one lens group consisting of three lenses. The middle group GM is made up of one lens group consisting of four lenses. The rear group GR is made up of three lens groups, in order from the object side to the image side: an aperture stop St and a first subsequent lens group GR1 consisting of six lenses, a second subsequent lens group GR2 consisting of one lens, and a third subsequent lens group GR3 consisting of one lens. The aperture stop St shown in FIG. 1 does not indicate the size or shape, but indicates the position on the optical axis. If the front group GF is configured to be made up of one lens group as in the example of FIG. 1, it is advantageous for miniaturization. If the middle group GM is configured to be made up of one lens group, it is advantageous for miniaturization.

[0100] As in the example of Figure 1, it is preferable that the front group GF includes a cemented lens in which a negative meniscus lens with a convex surface facing the object side and a positive lens with a convex surface facing the object side are cemented together in that order from the object side. In this case, it becomes easier to correct chromatic aberration of magnification at the wide-angle end and axial chromatic aberration at the telephoto end.

[0101] In the example of Fig. 1, during magnification change, the front group GF, the middle group GM, the first subsequent lens group GR1, and the second subsequent lens group GR2 move along the optical axis Z while changing the spacing between the adjacent lens groups, and the third subsequent lens group GR3 is stationary. In Fig. 1, between the Wide and Tele views, solid arrows indicate the general movement trajectory of each group that moves during magnification change from the wide-angle end to the telephoto end, and straight dotted lines in the vertical direction indicate each group that does not move during magnification change.

[0102] The variable magnification optical system in the example of Figure 1 is arranged with an image stabilization group that moves in a direction intersecting the optical axis Z during image blur compensation. Image blur compensation is performed by the movement of the image stabilization group. In the example of Figure 1, the image stabilization group is made up of the middle group GM. In Figure 1, up and down arrows are drawn on the lens groups that correspond to the image stabilization group. When the image stabilization group is arranged in the middle group, it is advantageous to limit the amount of movement of the image stabilization group during image blur compensation.

[0103] The variable magnification optical system in the example of Figure 1 also has a focusing group that moves along the optical axis Z during focusing. Focusing is achieved by the movement of the focusing group. In the example of Figure 1, the focusing group is made up of the second subsequent lens group GR2. In Figure 1, the lens group corresponding to the focusing group is marked with a left-right arrow indicating the direction of movement when focusing from an object at infinity to the nearest object.

[0104] Next, preferred and possible configurations for the conditional expressions of the variable magnification optical system of the present disclosure will be described. In the following description of the conditional expressions, in order to avoid redundant explanations, the same symbols are used for elements with the same definitions, and redundant explanations of the symbols are omitted. In addition, in the following, in order to avoid redundant explanations, the "variable magnification optical system of the present disclosure" will also be simply referred to as the "variable magnification optical system."

[0105] It is preferable that the variable magnification optical system satisfies the following conditional expression (1). Here, the back focus in the air equivalent distance of the entire system when focused on an object at infinity at the wide-angle end is Bfw. And, the sum of the distance on the optical axis from the lens surface of the front group GF closest to the object to the lens surface of the rear group GR closest to the image when focused on an object at infinity at the wide-angle end and the back focus Bfw is TLw. And, the focal length of the entire system when focused on an object at infinity at the wide-angle end is fw. The maximum half angle of view when focused on an object at infinity at the wide-angle end is ωw. TLw is the total length when focused on an object at infinity at the wide-angle end. In conditional expression (1), tan is the tangent, and this notation is the same for other conditional expressions. By making sure that the corresponding value of conditional expression (1) is not below the lower limit, it is advantageous to suppress various aberrations in the entire range of variable magnification. By making sure that the corresponding value of conditional expression (1) is not equal to or greater than the upper limit, it is possible to work to make the entire optical system more compact. 5 <TLw / (fw×tanωw)<12 (1)

[0106] In order to obtain better characteristics, it is preferable to replace the lower limit of 5 in condition (1) with any of 5.5, 6, 6.5, and 7. It is also preferable to replace the upper limit of 12 in condition (1) with any of 11, 10.5, 10, and 9.5.

[0107] Fig. 2 shows a cross-sectional view of the variable magnification optical system of Fig. 1, and shows, as an example, the back focus Bfw and the total length TLw of this variable magnification optical system. In Fig. 2, the upper row labeled "Wide" shows the wide-angle end state, and the lower row labeled "Tele" shows the telephoto end state.

[0108] As described above, when the back focus in the air-equivalent distance of the entire system when focused on an object at infinity at the wide-angle end is Bfw, it is preferable that the variable magnification optical system satisfies the following conditional expression (2). The back focus in the air-equivalent distance is the air-equivalent distance on the optical axis from the lens surface of the rear group GR closest to the image side to the image surface Sim. By ensuring that the corresponding value of conditional expression (2) is not below the lower limit, the back focus Bfw defined above does not become too short, making it easy to attach a mount exchange mechanism. By ensuring that the corresponding value of conditional expression (2) is not above the upper limit, the back focus Bfw defined above does not become too long, making it easy to achieve a compact design. 0.5 <Bfw / (fw×tanωw)<2.5 (2)

[0109] To obtain better characteristics, it is preferable to replace the lower limit of condition (2) from 0.5 with any of 0.6, 0.68, 0.75, and 0.8. It is also preferable to replace the upper limit of condition (2) from 2.5 with any of 2.3, 2.1, 1.84, and 1.7. For example, it is more preferable that the variable magnification optical system satisfies the following condition (2-1). 0.75 <Bfw / (fw×tanωw)<1.84 (2-1)

[0110] It is preferable that the variable magnification optical system satisfies the following conditional formula (3). Here, Fnot is the maximum F-number when the lens is focused on an object at infinity at the telephoto end. TLt is the sum of the distance on the optical axis from the lens surface of the front group GF closest to the object to the lens surface of the rear group GR closest to the image when the lens is focused on an object at infinity at the telephoto end and the back focus in the air equivalent distance of the entire system when the lens is focused on an object at infinity at the telephoto end. ft is the focal length of the entire system when the lens is focused on an object at infinity at the telephoto end. TLt is the total length when the lens is focused on an object at infinity at the telephoto end. As an example, the above total length TLt is shown in FIG. 2. By making sure that the corresponding value of conditional formula (3) is not equal to or less than the lower limit, it is advantageous to suppress various aberrations over the entire range of variable magnification. By making sure that the corresponding value of conditional formula (3) is not equal to or more than the upper limit, it is advantageous to reduce the total length while reducing the F-number at the telephoto end. 1.8 <Fnot×(TLt / ft)<5 (3)

[0111] In order to obtain better characteristics, it is preferable to replace the lower limit of 1.8 in condition (3) with any of 1.9, 2, 2.1, and 2.2. Also, it is preferable to replace the upper limit of 5 in condition (3) with any of 4.6, 4.3, 4.1, and 4. For example, it is more preferable for the variable magnification optical system to satisfy the following condition (3-1), it is even more preferable for it to satisfy the following condition (3-2), and it is even more preferable for it to satisfy the following condition (3-3). 1.9 <Fnot×(TLt / ft)<4.6 (3-1) 2 <Fnot×(TLt / ft)<4.3 (3-2) 2.2 <Fnot×(TLt / ft)<4 (3-3)

[0112] It is preferable that the variable magnification optical system satisfies the following conditional expression (4). By ensuring that the corresponding value of conditional expression (4) is not below the lower limit, it is advantageous for suppressing various aberrations throughout the entire range of variable magnification. By ensuring that the corresponding value of conditional expression (4) is not above the upper limit, it is advantageous for reducing the F-number at the telephoto end. In addition, since the total optical length at the wide-angle end does not become too long, it is advantageous for compactness. 0.34<(fw×TLw×Fnot) / ft 2 <0.97 (4)

[0113] In order to obtain better characteristics, it is preferable to replace the lower limit of condition (4) from 0.34 with any of 0.36, 0.38, 0.4, 0.41, and 0.42. It is also preferable to replace the upper limit of condition (4) from 0.97 with any of 0.92, 0.87, 0.83, 0.8, and 0.77. For example, it is more preferable for the variable magnification optical system to satisfy the following condition (4-1), it is even more preferable for it to satisfy the following condition (4-2), and it is even more preferable for it to satisfy the following condition (4-3). 0.36<(fw×TLw×Fnot) / ft 2 <0.92 (4-1) 0.38<(fw×TLw×Fnot) / ft 2 <0.87 (4-2) 0.41<(fw×TLw×Fnot) / ft 2 <0.8 (4-3)

[0114] If the maximum F-number when focused on an object at infinity at the wide-angle end is Fnow, it is preferable that the variable magnification optical system satisfies the following conditional expression (5). By making sure that the corresponding value of conditional expression (5) is not below the lower limit, it becomes easy to reduce the maximum F-number at the wide-angle end while widening the angle of view at the wide-angle end. By making sure that the corresponding value of conditional expression (5) is not above the upper limit, it is advantageous to suppress an increase in the number of lenses and an increase in the size of the optical system while obtaining good optical performance. 0.075 <tanωw / Fnow<0.3 (5)

[0115] In order to obtain better characteristics, it is preferable to replace the lower limit of condition (5) from 0.075 with either 0.092 or 0.105. Also, it is preferable to replace the upper limit of condition (5) from 0.3 with either 0.27 or 0.25. For example, it is more preferable for the variable magnification optical system to satisfy the following condition (5-1), and it is even more preferable for it to satisfy the following condition (5-2). 0.092 <tanωw / Fnow<0.27 (5-1) 0.105 <tanωw / Fnow<0.25 (5-2)

[0116] It is preferable that the variable magnification optical system satisfies the following conditional expression (6). By making sure that the corresponding value of conditional expression (6) is not below the lower limit, it is advantageous for suppressing various aberrations over the entire range of variable magnification. By making sure that the corresponding value of conditional expression (6) is not above the upper limit, it is advantageous for size reduction because the total optical length at the telephoto end does not become too long. 1.1 <TLt / TLw<1.9 (6)

[0117] To obtain better characteristics, it is preferable to replace the lower limit of 1.1 in condition (6) with either 1.13 or 1.15. It is also preferable to replace the upper limit of 1.9 in condition (6) with either 1.68 or 1.48. For example, it is more preferable that the variable magnification optical system satisfies the following condition (6-1). 1.15 <TLt / TLw<1.48 (6-1)

[0118] It is preferable that the variable magnification optical system satisfies the following conditional expression (7). Here, the focal length of the front group GF when focused on an object at infinity at the wide-angle end is designated as fFw. The focal length of the middle group GM when focused on an object at infinity at the wide-angle end is designated as fMw. By ensuring that the corresponding value of conditional expression (7) is not below the lower limit, the refractive power of the middle group GM does not become too weak, making it easy to suppress the amount of movement of the middle group GM when varying magnification. By ensuring that the corresponding value of conditional expression (7) is not above the upper limit, the refractive power of the front group GF does not become too weak, making it easy to suppress the amount of movement of the middle group GM when varying magnification. Since it does not become too large, it becomes easier to prevent the front group GF from becoming too large. 0.8 <fFw / (-fMw)<8 (7)

[0119] To obtain better characteristics, it is preferable to replace the lower limit of condition (7) from 0.8 with any of 0.9, 1, or 1.1. Also, it is preferable to replace the upper limit of condition (7) from 8 with any of 7, 6, or 5.3. For example, it is more preferable that the variable magnification optical system satisfies the following condition (7-1). 1.1 <fFw / (-fMw)<5.3 (7-1)

[0120] It is preferable that the variable magnification optical system satisfies the following conditional expression (8). By making sure that the corresponding value of conditional expression (8) is not below the lower limit, it becomes easy to suppress various aberrations at the wide-angle end. By making sure that the corresponding value of conditional expression (8) is not above the upper limit, it becomes easy to shorten the total optical length at the wide-angle end. 0.8 <TLw / ft<1.5 (8)

[0121] In order to obtain better characteristics, it is preferable to change the lower limit of condition (8) from 0.8 to either 0.83 or 0.85, and it is also preferable to change the upper limit of condition (8) from 1.5 to either 1.3 or 1.2.

[0122] It is preferable that the variable magnification optical system satisfies the following conditional expression (9). By making sure that the corresponding value of conditional expression (9) is not below the lower limit, the variable magnification ratio does not become too low, and the variable magnification optical system can fully demonstrate its value. By making sure that the corresponding value of conditional expression (9) is not above the upper limit, the variable magnification ratio does not become too high, and the movement amount of the lens group can be prevented from becoming excessive, which is advantageous for miniaturizing the entire optical system. 2.1 <ft / fw<6 (9)

[0123] In order to obtain better characteristics, it is preferable to replace the lower limit of condition (9) from 2.1 with any of 2.3, 2.5, and 2.6, and it is preferable to replace the upper limit of condition (9) from 6 with any of 5.5, 5, and 4.7.

[0124] If the focal length of the lens group closest to the object in the front group GF is fF1, it is preferable that the variable magnification optical system satisfies the following conditional expression (10). By ensuring that the corresponding value of conditional expression (10) is not below the lower limit, the refractive power of the front group GF will not become too strong, which is advantageous for suppressing aberration fluctuations during magnification variation. By ensuring that the corresponding value of conditional expression (10) is not above the upper limit, the refractive power of the front group GF will not become too weak, which is advantageous for making the front group GF more compact. 1.5 <fF1 / fw<12 (10)

[0125] In order to obtain better characteristics, it is preferable to replace the lower limit of condition (10) from 1.5 with any of 1.7, 1.9, 2, or 2.05, and it is also preferable to replace the upper limit of condition (10) from 12 with any of 11, 10, 9, or 8.

[0126] It is preferable that the variable magnification optical system satisfies the following conditional expression (11). By making sure that the corresponding value of conditional expression (11) is not below the lower limit, the refractive power of the intermediate group does not become too weak, which is advantageous for suppressing the amount of movement of the front group GF during magnification change when the intermediate group moves during magnification change. By making sure that the corresponding value of conditional expression (11) is not above the upper limit, the refractive power of the front group GF does not become too weak, which is advantageous for suppressing an increase in the size of the front group GF. 2 <fF1 / (-fMw)<13 (11)

[0127] In order to obtain better characteristics, it is preferable to replace the lower limit of 2 in condition (11) with any of 2.2, 2.4, 2.5, and 2.6, and it is preferable to replace the upper limit of 13 in condition (11) with any of 12.5, 12, 11.5, and 11.

[0128] It is preferable that the variable magnification optical system satisfy the following conditional expression (12). By ensuring that the corresponding value of conditional expression (12) is not below the lower limit, the refractive power of the front group GF does not become too strong, which is advantageous for suppressing aberration fluctuations during magnification variation. By ensuring that the corresponding value of conditional expression (12) is not above the upper limit, the refractive power of the front group GF does not become too weak, which is advantageous for making the front group GF more compact. 0.7 <fF1 / (fw×ft) 1 / 2 <4.7 (12)

[0129] In order to obtain better characteristics, it is preferable to replace the lower limit of condition (12) from 0.7 with any of 0.9, 1, or 1.05, and it is also preferable to replace the upper limit of condition (12) from 4.7 with any of 4.3, 4, or 2.

[0130] It is preferable that the variable magnification optical system satisfies the following conditional expression (13). By ensuring that the corresponding value of conditional expression (13) is not below the lower limit, the refractive power of the intermediate group does not become too strong, so that the amount of aberration of field curvature generated in the intermediate group can be suppressed, which is advantageous for aberration correction when varying magnification. By ensuring that the corresponding value of conditional expression (13) is not above the upper limit, the refractive power of the intermediate group does not become too weak, so that the amount of movement of the intermediate group when varying magnification can be suppressed. This ensures that the total optical length does not become too long, which is advantageous for size reduction. 0.18<(-fMw) / (fw×ft) 1 / 2 <0.8 (13)

[0131] In order to obtain better characteristics, it is preferable to change the lower limit of condition (13) from 0.18 to either 0.2 or 0.22, and it is also preferable to change the upper limit of condition (13) from 0.8 to either 0.7 or 0.6.

[0132] It is preferable that the variable magnification optical system satisfies the following conditional expression (14). Making sure that the corresponding value of conditional expression (14) is not below the lower limit is advantageous for improving performance. Making sure that the corresponding value of conditional expression (14) is not above the upper limit is advantageous for making the front group GF smaller, since the refractive power of the front group GF does not become too weak. 1.3 <fF1 / (ft / Fnot)<8 (14)

[0133] In order to obtain better characteristics, it is preferable to replace the lower limit of 1.3 in condition (14) with any of 1.5, 1.7, and 1.75. Also, it is preferable to replace the upper limit of 8 in condition (14) with any of 7, 6, and 2.7. For example, it is more preferable that the variable magnification optical system satisfy the following condition (14-1). 1.75 <fF1 / (ft / Fnot)<2.7 (14-1)

[0134] In a configuration in which the variable magnification optical system includes an aperture stop St on the image side of the lens surface closest to the image side of the middle group GM, it is preferable that the variable magnification optical system satisfies the following conditional expression (15). Here, the distance on the optical axis from the lens surface closest to the object side of the front group GF to the aperture stop St in a state in which the lens surface is focused on an object at infinity at the wide-angle end is defined as DDL1STw. As an example, the above distance DDL1STw is shown in FIG. 2. By making the corresponding value of conditional expression (15) not smaller than the lower limit, the movable range of the middle group GM does not become too small, which is advantageous for achieving a high variable magnification ratio. Alternatively, the refractive power of the front group GF does not become too weak, which is advantageous for achieving both compactness and a high variable magnification ratio. By making the corresponding value of conditional expression (15) not larger than the upper limit, the distance from the lens surface closest to the object side of the front group GF to the entrance pupil position at the wide-angle end does not become too long, which prevents the diameter of the front group GF from becoming large, which is advantageous for achieving compactness. Alternatively, by making sure that the corresponding value of conditional expression (15) is not greater than the upper limit, the refractive power of the front group GF will not become too strong, which is advantageous for improving performance. 0.1 <DDL1STw / fF1<0.9 (15)

[0135] In order to obtain better characteristics, it is preferable to change the lower limit of condition (15) from 0.1 to either 0.13 or 0.15, and it is also preferable to change the upper limit of condition (15) from 0.9 to either 0.75 or 0.66.

[0136] In a configuration in which the variable magnification optical system includes an aperture stop St, it is preferable that the variable magnification optical system satisfies the following conditional expression (16). By making sure that the corresponding value of conditional expression (16) is not equal to or less than the lower limit, the distance between the aperture stop St and the front group GF on the wide-angle side is not too short, and the distance from the lens surface of the front group GF closest to the object to the entrance pupil position is not too short, which makes it easy to suppress aberration fluctuations during magnification. By making sure that the corresponding value of conditional expression (16) is not equal to or greater than the upper limit, the distance between the aperture stop St and the front group GF on the wide-angle side is not too long, and the distance from the lens surface of the front group GF closest to the object to the entrance pupil position is not too long. This makes it possible to suppress an increase in the diameter of the front group GF, which is advantageous for miniaturization. 0.18 <DDL1STw / TLw<0.75 (16)

[0137] In order to obtain better characteristics, it is preferable to change the lower limit of condition (16) from 0.18 to either 0.2 or 0.22, and it is also preferable to change the upper limit of condition (16) from 0.75 to either 0.6 or 0.52.

[0138] If the focal length of the rear group GR when focused on an object at infinity at the wide-angle end is fRw, it is preferable that the variable magnification optical system satisfies the following conditional expression (17). By ensuring that the corresponding value of conditional expression (17) is not below the lower limit, it is easy to shorten the total optical length at the wide-angle end, which is advantageous for size reduction. By ensuring that the corresponding value of conditional expression (17) is not above the upper limit, it is advantageous for suppressing spherical aberration at the wide-angle end. 0.7 <fw / fRw<3 (17)

[0139] In order to obtain better characteristics, it is preferable to change the lower limit of condition (17) from 0.7 to either 0.8 or 0.9, and it is also preferable to change the upper limit of condition (17) from 3 to either 2.5 or 2.3.

[0140] If the focal length of the rear group GR when focused on an object at infinity at the telephoto end is fRt, it is preferable that the variable magnification optical system satisfies the following conditional expression (18). By ensuring that the corresponding value of conditional expression (18) is not below the lower limit, it is easy to shorten the total optical length at the telephoto end, which is advantageous for size reduction. By ensuring that the corresponding value of conditional expression (18) is not above the upper limit, it is advantageous for suppressing spherical aberration at the telephoto end. 1.1 <ft / fRt<7 (18)

[0141] In order to obtain better characteristics, it is preferable to change the lower limit of condition (18) from 1.1 to either 1.3 or 1.5, and it is also preferable to change the upper limit of condition (18) from 7 to either 6 or 5.2.

[0142] If the focal length of the lens group closest to the object in the rear group GR is fR1, it is preferable that the variable magnification optical system satisfies the following conditional expression (19). By making sure that the corresponding value of conditional expression (19) is not below the lower limit, the refractive power of the lens group closest to the object in the rear group GR will not become too strong, which is advantageous for suppressing aberration fluctuations during magnification. By making sure that the corresponding value of conditional expression (19) is not above the upper limit, the refractive power of the lens group closest to the object in the rear group GR will not become too weak, which is advantageous for size reduction. 0.05 <fR1 / (fw×ft) 1 / 2 <3 (19)

[0143] In order to obtain better characteristics, it is preferable to replace the lower limit of condition (19) from 0.05 with any of 0.15, 0.25, or 0.3, and it is also preferable to replace the upper limit of condition (19) from 3 with any of 2, 1.5, or 1.

[0144] It is preferable that the variable magnification optical system satisfies the following conditional expression (20). By ensuring that the corresponding value of conditional expression (20) is not below the lower limit, the positive refractive power of the lens unit closest to the object in the rear group GR does not become too weak, which is advantageous for correcting spherical aberration, particularly at the wide-angle end. By ensuring that the corresponding value of conditional expression (20) is not above the upper limit, the positive refractive power of the lens unit closest to the object in the rear group GR does not become too strong, which is advantageous for suppressing fluctuations in spherical aberration during magnification. 0.05 <fw / fR1<2.5 (20)

[0145] In order to obtain better characteristics, it is preferable to replace the lower limit of condition (20) from 0.05 to any of 0.3, 0.45, or 0.57, and it is also preferable to replace the upper limit of condition (20) from 2.5 to any of 2.1, 1.8, or 1.1.

[0146] In a configuration in which the vibration reduction group is disposed closer to the image side than the front group GF, it is preferable that the variable magnification optical system satisfies the following conditional expression (21). Here, the focal length of the vibration reduction group is taken as fIS. Ensuring that the corresponding value of conditional expression (21) is not below the lower limit is advantageous for shortening the overall optical length. Ensuring that the corresponding value of conditional expression (21) is not above the upper limit can ensure the refractive power of the vibration reduction group, making it easier to suppress the amount of movement of the vibration reduction group during image blur correction, which is advantageous for size reduction. 0.07<|fIS / ft|<0.5 (21)

[0147] In order to obtain better characteristics, it is preferable to change the lower limit of condition (21) from 0.07 to either 0.09 or 0.1, and it is also preferable to change the upper limit of condition (21) from 0.5 to either 0.4 or 0.35.

[0148] In a configuration in which the front group GF includes a cemented lens in which a negative meniscus lens with a convex surface facing the object side and a positive lens with a convex surface facing the object side are cemented together in this order from the object side, it is preferable that the variable magnification optical system satisfies the following conditional expression (22). Here, the refractive index of the negative meniscus lens included in the front group GF with respect to the d-line is Ndn. The Abbe number of the negative meniscus lens included in the front group GF with respect to the d-line is νdn. By making the corresponding value of conditional expression (22) not equal to or less than the lower limit, a material other than a material with a low refractive index and a low Abbe number can be selected, which makes it easy to correct the chromatic aberration of magnification at the wide-angle end. By making the corresponding value of conditional expression (22) not equal to or more than the upper limit, a material other than a material with a high refractive index and a high Abbe number can be selected, which makes it easy to select a material with a low specific gravity, which makes it easy to reduce the weight. Alternatively, the difference in Abbe number between the positive lens and the negative lens that constitute the front group GF does not become too small, so that the refractive power of each lens that constitutes the front group GF does not become strong. As a result, it becomes easier to correct high-order spherical aberration at the telephoto end. In this specification, "high-order" in relation to aberration means fifth order or higher. 1.94 <Ndn+0.01×νdn<2.5 (22)

[0149] In order to obtain better characteristics, it is preferable to change the lower limit of condition (22) from 1.94 to either 2 or 2.04, and it is also preferable to change the upper limit of condition (22) from 2.5 to either 2.35 or 2.3.

[0150] In a configuration in which the front group GF includes a cemented lens in which a negative meniscus lens with a convex surface facing the object side and a positive lens with a convex surface facing the object side are cemented together in this order from the object side, it is preferable that the variable magnification optical system satisfies the following conditional expression (23). Here, the refractive index of the positive lens included in the front group GF with respect to the d-line is Ndp. The Abbe number of the positive lens included in the front group GF with respect to the d-line is νdp. By making the corresponding value of conditional expression (23) not equal to or less than the lower limit, a material other than a material with a low refractive index and a low Abbe number can be selected, so that an increase in high-order aberration of spherical aberration at the telephoto end can be suppressed, which makes it easy to improve performance. Alternatively, it is possible to suppress undercorrection of axial chromatic aberration at the telephoto end. By making the corresponding value of conditional expression (23) not equal to or more than the upper limit, a material other than a material with a high refractive index and a high Abbe number can be selected, so that a material with a low specific gravity can be selected, which makes it easy to reduce weight. Alternatively, it is possible to suppress overcorrection of axial chromatic aberration at the telephoto end. 2 <Ndp+0.01×νdp<2.6 (23)

[0151] In order to obtain better characteristics, it is preferable to replace the lower limit of 2 in condition (23) with either 2.1 or 2.16, and it is also preferable to replace the upper limit of 2.6 in condition (23) with either 2.45 or 2.4.

[0152] If the average Abbe number based on the d-line of all the positive lenses in the front group GF is denoted as νdFp_ave, it is preferable that the variable magnification optical system satisfies the following conditional expression (24). Ensuring that the corresponding value of conditional expression (24) is not below the lower limit is advantageous for correction of axial chromatic aberration, particularly at the telephoto end. Ensuring that the corresponding value of conditional expression (24) is not above the upper limit is advantageous for correction of various aberrations other than chromatic aberration. 55<νdFp_ave<95 (24)

[0153] In order to obtain better characteristics, it is preferable to change the lower limit of condition (24) from 55 to either 60 or 63, and it is also preferable to change the upper limit of condition (24) from 95 to either 90 or 88.5.

[0154] If the thickness on the optical axis of the lens group closest to the object in the front group GF is dF1, it is preferable that the variable magnification optical system satisfies the following condition (25). As an example, the above thickness dF1 is shown in FIG. 2. Making sure that the corresponding value of condition (25) is not below the lower limit is advantageous for ensuring the strength of the lens group closest to the object in the front group GF. Making sure that the corresponding value of condition (25) is not above the upper limit is advantageous for reducing the weight of the front group GF. 0.03 <dF1 / fF1<0.35 (25)

[0155] In order to obtain better characteristics, it is preferable to change the lower limit of condition (25) from 0.03 to either 0.035 or 0.04, and it is also preferable to change the upper limit of condition (25) from 0.35 to either 0.3 or 0.27.

[0156] If the average value of the specific gravity of all the lenses in the front group GF is GFave, it is preferable that the variable magnification optical system satisfies the following conditional expression (26). By ensuring that the corresponding value of conditional expression (26) is not below the lower limit, it is possible to use materials that are easily available, which is advantageous for realizing a variable magnification optical system in which spherical aberration and axial chromatic aberration are suppressed. By ensuring that the corresponding value of conditional expression (26) is not above the upper limit, it is advantageous for reducing the weight of the front group GF. 2 <GFave<4.3 (26)

[0157] In order to obtain better characteristics, it is preferable to change the lower limit of condition (26) from 2 to either 2.5 or 2.75, and it is also preferable to change the upper limit of condition (26) from 4.3 to either 4 or 3.7.

[0158] Note that the example shown in Fig. 1 is just one example, and various modifications are possible within the scope of the gist of the technology of the present disclosure. For example, the number of lens groups included in each of the front group GF, the middle group GM, and the rear group GR, the number of lenses included in each lens group, the number of lenses included in the vibration reduction group, and the number of lenses included in the focusing group may be different from the example of Fig. 1. The lens group corresponding to the vibration reduction group and the lens group corresponding to the focusing group may be different from the example of Fig. 1. Although Fig. 1 shows an example in which the variable magnification optical system is a zoom lens, the variable magnification optical system of the present disclosure may be a zoom lens or a varifocal lens.

[0159] In the example of Fig. 1, the variable magnification optical system includes only one focusing group, but the variable magnification optical system of the present disclosure may include multiple focusing groups, for example, two focusing groups. If the two focusing groups are arranged in the rear group GR, the amount of movement of each focusing group during focusing can be reduced. If the one or more focusing groups included in the variable magnification optical system are arranged only in the rear group GR, breathing caused by focusing can be reduced.

[0160] The lens group that does not move during magnification may be a lens group different from the example in Figure 1, or all of the lens groups may move during magnification. For example, at least one lens group that does not move during magnification may be arranged between the front group GF and the lens group closest to the image side of the rear group GR. In this case, the number of cams that move the lens groups can be reduced, thereby simplifying the lens drive mechanism.

[0161] The front group GF may be configured to consist of two lens groups, which is advantageous in suppressing fluctuations in aberrations during zooming.

[0162] The middle group GM may be configured to consist of two lens groups, which is advantageous in suppressing aberration fluctuations during magnification change.

[0163] The rear group GR may be configured to be composed of three lens groups, four lens groups, five lens groups, or six lens groups. By making the number of lens groups constituting the rear group GR four or more, it becomes easier to suppress aberration fluctuations during magnification change. More specifically, the rear group GR can be configured, for example, as follows.

[0164] The rear group GR may be configured to include, in order from the object side to the image side, a first rear lens group GR1 having positive refractive power, a second rear lens group GR2 having negative refractive power, and a third rear lens group GR3 having positive refractive power. By limiting the number of lens groups included in the rear group GR to three in this way, it becomes easier to shorten the overall optical length.

[0165] In a configuration in which the rear group GR is composed of, in order from the object side to the image side, a first subsequent lens group GR1 having positive refractive power, a second subsequent lens group GR2 having negative refractive power, and a third subsequent lens group GR3, it is preferable that the variable magnification optical system satisfies at least one of the following conditional expressions (27) and (28). In the conditional expressions (27) and (28), the symbols are defined as follows. The focal length of the first subsequent lens group GR1 is fR1. The focal length of the second subsequent lens group GR2 is fR2. The focal length of the third subsequent lens group GR3 is fR3. 0.05 <fR1 / fR3<0.6 (27) 0.2 <fR1 / (-fR2)<1 (28)

[0166] By ensuring that the corresponding value of conditional expression (27) is not equal to or less than the lower limit, the refractive power of the first subsequent lens group GR1 does not become too strong, which is advantageous for suppressing overcorrection of spherical aberration at the telephoto end. By ensuring that the corresponding value of conditional expression (27) is not equal to or greater than the upper limit, the positive refractive power of the third subsequent lens group GR3 does not become too strong, which is advantageous for ensuring an appropriate back focus length.

[0167] In order to obtain better characteristics, it is preferable to replace the lower limit of condition (27) from 0.05 with any of 0.08, 0.1, 0.12, or 0.14, and it is also preferable to replace the upper limit of condition (27) from 0.6 with any of 0.5, 0.45, 0.4, or 0.35.

[0168] By ensuring that the corresponding value of conditional expression (28) is not below the lower limit, the refractive power of the second subsequent lens group GR2 does not become too weak, which is advantageous for suppressing aberration fluctuations during zooming. By ensuring that the corresponding value of conditional expression (28) is not above the upper limit, the refractive power of the first subsequent lens group GR1 does not become too weak, which is advantageous for suppressing spherical aberration at the telephoto end.

[0169] In order to obtain better characteristics, it is preferable to replace the lower limit of 0.2 in condition (28) with any of 0.3, 0.4, 0.45, or 0.5, and it is also preferable to replace the upper limit of 1 in condition (28) with any of 0.9, 0.8, 0.75, or 0.7.

[0170] Alternatively, the rear group GR may be configured to include, in order from the object side to the image side, a first rear lens group GR1 having positive refractive power, a second rear lens group GR2 having positive refractive power, and a third rear lens group GR3 having negative refractive power. By limiting the number of lens groups included in the rear group GR to three in this way, it becomes easier to shorten the overall optical length.

[0171] In a configuration in which the rear group GR is composed of, in order from the object side to the image side, a first subsequent lens group GR1 having positive refractive power, a second subsequent lens group GR2 having positive refractive power, and a third subsequent lens group GR3 having negative refractive power, it is preferable that the variable magnification optical system satisfies at least one of the following conditional expressions (29) and (30). In the conditional expressions (29) and (30), the symbols are defined as follows. The focal length of the first subsequent lens group GR1 is fR1. The focal length of the second subsequent lens group GR2 is fR2. The focal length of the third subsequent lens group GR3 is fR3. 0.5 <fR1 / (-fR3)<1.6 (29) 0.8 <fR2 / (-fR3)<3 (30)

[0172] By ensuring that the corresponding value of conditional expression (29) is not below the lower limit, the refractive power of the third subsequent lens group GR3 does not become too weak, which is advantageous for suppressing aberration fluctuations during zooming. By ensuring that the corresponding value of conditional expression (29) is not above the upper limit, the refractive power of the first subsequent lens group GR1 does not become too weak, which is advantageous for suppressing spherical aberration at the telephoto end.

[0173] In order to obtain better characteristics, it is preferable to replace the lower limit of condition (29) from 0.5 with any of 0.6, 0.7, 0.8, or 0.9, and it is also preferable to replace the upper limit of condition (29) from 1.6 with any of 1.5, 1.4, 1.3, or 1.2.

[0174] By ensuring that the corresponding value of conditional expression (30) is not below the lower limit, the refractive power of the third subsequent lens group GR3 does not become too weak, which is advantageous for suppressing aberration fluctuations during zooming. By ensuring that the corresponding value of conditional expression (30) is not above the upper limit, the refractive power of the second subsequent lens group GR2 does not become too weak, which is advantageous for suppressing spherical aberration at the telephoto end.

[0175] In order to obtain better characteristics, it is preferable to replace the lower limit of condition (30) from 0.8 with any of 1, 1.1, 1.2, or 1.3, and it is also preferable to replace the upper limit of condition (30) from 3 with any of 2.5, 2.2, 2, or 1.8.

[0176] Alternatively, as shown in the embodiment described later, the rear group GR may be configured to include, in order from the most object side to the image side, at least a first rear lens group GR1 having a positive refractive power, a second rear lens group GR2 having a positive refractive power, a third rear lens group GR3 having a negative refractive power, and a fourth rear lens group GR4 having a positive refractive power. By including at least four lens groups in this way, it becomes easier to suppress aberration fluctuations during magnification change.

[0177] In a configuration in which the rear group GR includes, in succession from the most object side to the image side, at least a first subsequent lens group GR1 having positive refractive power, a second subsequent lens group GR2 having positive refractive power, a third subsequent lens group GR3 having negative refractive power, and a fourth subsequent lens group GR4 having positive refractive power, it is preferable that the variable magnification optical system satisfies at least one of the following conditional expressions (29A), (30A), (31), and (32). In the conditional expressions (29A), (30A), (31), and (32), the symbols are defined as follows. The focal length of the first subsequent lens group GR1 is fR1. The focal length of the second subsequent lens group GR2 is fR2. The focal length of the third subsequent lens group GR3 is fR3. The focal length of the fourth subsequent lens group GR4 is fR4. 0.9 <fR1 / (-fR3)<10 (29A) 0.1 <fR2 / (-fR3)<1.8 (30A) 1.2 <fR1 / fR2<11 (31) 0.1 <fR2 / fR4<1.5 (32)

[0178] By ensuring that the corresponding value of conditional formula (29A) is not below the lower limit, the refractive power of the third subsequent lens group GR3 does not become too weak, which is advantageous for suppressing aberration fluctuations during zooming. By ensuring that the corresponding value of conditional formula (29A) is not above the upper limit, the refractive power of the first subsequent lens group GR1 does not become too weak, which is advantageous for suppressing spherical aberration at the telephoto end.

[0179] In order to obtain better characteristics, it is preferable to replace the lower limit of condition (29A) from 0.9 with any of 1, 1.1, 1.2, or 1.3, and it is also preferable to replace the upper limit of condition (29A) from 10 with any of 8, 6, 4.5, or 3.

[0180] By ensuring that the corresponding value of conditional formula (30A) is not below the lower limit, the refractive power of the third subsequent lens group GR3 does not become too weak, which is advantageous for suppressing aberration fluctuations during zooming. By ensuring that the corresponding value of conditional formula (30A) is not above the upper limit, the refractive power of the second subsequent lens group GR2 does not become too weak, which is advantageous for suppressing spherical aberration at the telephoto end.

[0181] In order to obtain better characteristics, it is preferable to replace the lower limit of 0.1 in condition (30A) with any of 0.2, 0.3, 0.35, or 0.4, and it is also preferable to replace the upper limit of 1.8 in condition (30A) with any of 1.5, 1.3, 1.1, or 0.95.

[0182] By ensuring that the corresponding value of conditional expression (31) is not below the lower limit, the refractive power of the second subsequent lens group GR2 does not become too weak, which is advantageous for correcting spherical aberration at the telephoto end. By ensuring that the corresponding value of conditional expression (31) is not above the upper limit, the refractive power of the first subsequent lens group GR1 does not become too weak, which is advantageous for suppressing aberration fluctuations during zooming.

[0183] In order to obtain better characteristics, it is preferable to replace the lower limit of 1.2 in condition (31) with any of 1.3, 1.4, 1.5, or 1.6, and it is also preferable to replace the upper limit of 11 in condition (31) with any of 9, 7, 5, or 3.

[0184] By ensuring that the corresponding value of conditional expression (32) is not equal to or less than the lower limit, the refractive power of the fourth subsequent lens group GR4 does not become too weak, which is advantageous in preventing under-correction of aberrations during zooming. By ensuring that the corresponding value of conditional expression (32) is not equal to or greater than the upper limit, the refractive power of the fourth subsequent lens group GR4 does not become too strong, which is advantageous in preventing over-correction of aberrations during zooming.

[0185] In order to obtain better characteristics, it is preferable to replace the lower limit of 0.1 in condition (32) with any of 0.2, 0.3, 0.4, or 0.45, and it is also preferable to replace the upper limit of 1.5 in condition (32) with any of 1.3, 1.2, 1.1, or 1.

[0186] The rear group GR may be configured to include, in order from the object side to the image side, at least a first rear lens group GR1 having positive refractive power, a second rear lens group GR2 having negative refractive power, a third rear lens group GR3 having positive refractive power, and a fourth rear lens group GR4 having negative refractive power. By including at least four lens groups in this way, it becomes easier to suppress aberration fluctuations during magnification.

[0187] In a configuration in which the rear group GR includes, in succession from the most object side to the image side, at least a first subsequent lens group GR1 having positive refractive power, a second subsequent lens group GR2 having negative refractive power, a third subsequent lens group GR3 having positive refractive power, and a fourth subsequent lens group GR4 having negative refractive power, it is preferable that the variable magnification optical system satisfies at least one of the following conditional expressions (27A) and (32A). In the conditional expressions (27A) and (32A), the symbols are defined as follows. The focal length of the first subsequent lens group GR1 is fR1. The focal length of the second subsequent lens group GR2 is fR2. The focal length of the third subsequent lens group GR3 is fR3. The focal length of the fourth subsequent lens group GR4 is fR4. 0.25 <fR1 / fR3<6 (27A) 0.4 <fR2 / fR4<18 (32A)

[0188] By ensuring that the corresponding value of conditional formula (27A) is not below the lower limit, the refractive power of the first subsequent lens group GR1 does not become too strong, which is advantageous for suppressing overcorrection of spherical aberration at the telephoto end. By ensuring that the corresponding value of conditional formula (27A) is not above the upper limit, the positive refractive power of the third subsequent lens group GR3 does not become too strong, which is advantageous for ensuring an appropriate back focus length.

[0189] In order to obtain better characteristics, it is preferable to replace the lower limit of condition (27A) from 0.25 with any of 0.4, 0.45, 0.5, or 0.55, and it is also preferable to replace the upper limit of condition (27A) from 6 with any of 5, 4, 3.4, or 2.9.

[0190] By ensuring that the corresponding value of conditional formula (32A) is not below the lower limit, the refractive power of the fourth subsequent lens group GR4 does not become too weak, which is advantageous in preventing under-correction of aberrations during zooming. By ensuring that the corresponding value of conditional formula (32A) is not above the upper limit, the refractive power of the fourth subsequent lens group GR4 does not become too strong, which is advantageous in preventing over-correction of aberrations during zooming.

[0191] In order to obtain better characteristics, it is preferable to replace the lower limit of condition (32A) from 0.4 with any of 0.6, 0.8, 0.85, 0.9, or 0.95, and it is also preferable to replace the upper limit of condition (32A) from 18 with any of 13, 8, 7, 6, or 5.

[0192] As shown in the embodiment described later, the rear group GR may be configured to include, in order from the object side to the image side, a first rear lens group GR1 having positive refractive power, a second rear lens group GR2 having negative refractive power, a third rear lens group GR3 having positive refractive power, a fourth rear lens group GR4 having negative refractive power, a fifth rear lens group GR5 having positive refractive power, and a sixth rear lens group GR6 having negative refractive power. By configuring the rear group GR to include six lens groups in this way, it becomes easier to suppress aberration fluctuations during magnification change.

[0193] In a configuration in which the rear group GR is composed of, in order from the object side to the image side, a first subsequent lens group GR1 having positive refractive power, a second subsequent lens group GR2 having negative refractive power, a third subsequent lens group GR3 having positive refractive power, a fourth subsequent lens group GR4 having negative refractive power, a fifth subsequent lens group GR5 having positive refractive power, and a sixth subsequent lens group GR6 having negative refractive power, it is preferable that the variable magnification optical system satisfies at least one of the following conditional expressions (33) and (34). In the conditional expressions (33) and (34), the symbols are defined as follows. The focal length of the third subsequent lens group GR3 is fR3. The focal length of the fourth subsequent lens group GR4 is fR4. The focal length of the fifth subsequent lens group GR5 is fR5. The focal length of the sixth subsequent lens group GR6 is fR6. 0.2 <fR3 / fR5<2.5 (33) 0.04 <fR4 / fR6<4 (34)

[0194] By ensuring that the corresponding value of conditional expression (33) is not below the lower limit, the refractive power of the fifth subsequent lens group GR5 does not become too weak, which is advantageous for correcting distortion. By ensuring that the corresponding value of conditional expression (33) is not above the upper limit, the refractive power of the third subsequent lens group GR3 does not become too weak, which is advantageous for suppressing spherical aberration at the wide-angle end.

[0195] In order to obtain better characteristics, it is preferable to replace the lower limit of 0.2 in condition (33) with any of 0.25, 0.32, or 0.35, and it is also preferable to replace the upper limit of 2.5 in condition (33) with any of 2.1, 1.7, or 1.5.

[0196] By ensuring that the corresponding value of condition (34) is not below the lower limit, the refractive power of the sixth subsequent lens group GR6 does not become too weak, which is advantageous for correcting distortion aberration.By ensuring that the corresponding value of condition (34) is not above the upper limit, the refractive power of the fourth subsequent lens group GR4 does not become too weak, which is advantageous for correcting aberration during zooming.

[0197] In order to obtain better characteristics, it is preferable to replace the lower limit of condition (34) from 0.04 with any of 0.2, 0.6, or 0.8, and it is also preferable to replace the upper limit of condition (34) from 4 with any of 3.4, 2.8, or 2.2.

[0198] The rear group GR may be configured to include, in order from the object side to the image side, at least a first rear lens group GR1 having positive refractive power, a second rear lens group GR2 having positive refractive power, a third rear lens group GR3 having positive refractive power, and a fourth rear lens group GR4 having negative refractive power. By including at least four lens groups in this way, it becomes easier to suppress aberration fluctuations during magnification change.

[0199] In a configuration in which the rear group GR includes, in succession from the most object side to the image side, at least a first subsequent lens group GR1 having positive refractive power, a second subsequent lens group GR2 having positive refractive power, a third subsequent lens group GR3 having positive refractive power, and a fourth subsequent lens group GR4 having negative refractive power, it is preferable that the variable magnification optical system satisfies at least one of the following conditional expressions (31A), (35), and (36). In the conditional expressions (31A), (35), and (36), the symbols are defined as follows. The focal length of the first subsequent lens group GR1 is fR1. The focal length of the second subsequent lens group GR2 is fR2. The focal length of the third subsequent lens group GR3 is fR3. The focal length of the fourth subsequent lens group GR4 is fR4. 0.06 <fR1 / fR2<0.7 (31A) 0.5 <fR2 / fR3<11 (35) 0.2 <fR3 / (-fR4)<3 (36)

[0200] By ensuring that the corresponding value of conditional formula (31A) is not below the lower limit, the refractive power of the second subsequent lens group GR2 does not become too weak, which is advantageous for correcting spherical aberration at the telephoto end. By ensuring that the corresponding value of conditional formula (31A) is not above the upper limit, the refractive power of the first subsequent lens group GR1 does not become too weak, which is advantageous for suppressing aberration fluctuations during zooming.

[0201] In order to obtain better characteristics, it is preferable to replace the lower limit of condition (31A) from 0.06 with any of 0.1, 0.12, 0.14, or 0.16, and it is also preferable to replace the upper limit of condition (31A) from 0.7 with any of 0.6, 0.5, 0.4, or 0.36.

[0202] By ensuring that the corresponding value of conditional expression (35) is not below the lower limit, the refractive power of the third subsequent lens group GR3 does not become too weak, which is advantageous for correcting spherical aberration at the telephoto end. By ensuring that the corresponding value of conditional expression (35) is not above the upper limit, the refractive power of the second subsequent lens group GR2 does not become too weak, which is advantageous for suppressing aberration fluctuations during zooming.

[0203] In order to obtain better characteristics, it is preferable to replace the lower limit of condition (35) from 0.5 with any of 1, 1.3, 1.6, or 1.7, and it is also preferable to replace the upper limit of condition (35) from 11 with any of 9, 8, 7, or 6.7.

[0204] By ensuring that the corresponding value of conditional expression (36) is not below the lower limit, the refractive power of the fourth subsequent lens group GR4 does not become too weak, which is advantageous for suppressing aberration fluctuations during zooming. By ensuring that the corresponding value of conditional expression (36) is not above the upper limit, the refractive power of the third subsequent lens group GR3 does not become too weak, which is advantageous for suppressing spherical aberration at the telephoto end.

[0205] In order to obtain better characteristics, it is preferable to replace the lower limit of 0.2 in condition (36) with any of 0.4, 0.6, 0.8, or 1. It is also preferable to replace the upper limit of 3 in condition (36) with any of 2, 1.8, 1.4, or 1.3.

[0206] The rear group GR may be configured to include, in order from the object side to the image side, a first rear lens group GR1 having positive refractive power, a second rear lens group GR2 having positive refractive power, a third rear lens group GR3 having negative refractive power, and a fourth rear lens group GR4 having negative refractive power. By configuring the rear group GR to include four lens groups in this way, it becomes easier to suppress aberration fluctuations during magnification change.

[0207] In a configuration in which the rear group GR is composed of, in order from the object side to the image side, a first subsequent lens group GR1 having positive refractive power, a second subsequent lens group GR2 having positive refractive power, a third subsequent lens group GR3 having negative refractive power, and a fourth subsequent lens group GR4 having negative refractive power, it is preferable that the variable magnification optical system satisfies at least one of the following conditional expressions (31B) and (37). In the conditional expressions (31B) and (37), the symbols are defined as follows. The focal length of the first subsequent lens group GR1 is fR1. The focal length of the second subsequent lens group GR2 is fR2. The focal length of the third subsequent lens group GR3 is fR3. The focal length of the fourth subsequent lens group GR4 is fR4. 0.6 <fR1 / fR2<4 (31B) 0.05 <fR3 / fR4<1 (37)

[0208] By ensuring that the corresponding value of condition (31B) is not below the lower limit, the refractive power of the second subsequent lens group GR2 does not become too weak, which is advantageous for correcting spherical aberration at the telephoto end. By ensuring that the corresponding value of condition (31B) is not above the upper limit, the refractive power of the first subsequent lens group GR1 does not become too weak, which is advantageous for suppressing aberration fluctuations during zooming.

[0209] In order to obtain better characteristics, it is preferable to replace the lower limit of 0.6 in condition (31B) with any of 0.9, 1.1, 1.3, or 1.4, and it is also preferable to replace the upper limit of 4 in condition (31B) with any of 3, 2.5, 2.2, or 1.9.

[0210] By ensuring that the corresponding value of condition (37) is not below the lower limit, the refractive power of the fourth subsequent lens group GR4 does not become too weak, which is advantageous for correcting distortion aberration. By ensuring that the corresponding value of condition (37) is not above the upper limit, the refractive power of the third subsequent lens group GR3 does not become too weak, which is advantageous for correcting aberration during zooming.

[0211] In order to obtain better characteristics, it is preferable to replace the lower limit of 0.05 in condition (37) with any of 0.1, 0.15, 0.18, or 0.2, and it is preferable to replace the upper limit of 1 in condition (37) with any of 0.7, 0.5, 0.35, or 0.3.

[0212] The rear group GR may be configured to include, in order from the object side to the image side, at least a first rear lens group GR1 having a positive refractive power, a second rear lens group GR2 having a negative refractive power, and a third rear lens group GR3 having a negative refractive power. By including at least three lens groups in this way, it becomes easier to suppress aberration fluctuations during magnification change.

[0213] In a configuration in which the rear group GR includes, in succession from the object side to the image side, at least a first subsequent lens group GR1 having positive refractive power, a second subsequent lens group GR2 having negative refractive power, and a third subsequent lens group GR3 having negative refractive power, it is preferable that the variable magnification optical system satisfies at least one of the following conditional expressions (28A) and (35A). In the conditional expressions (28A) and (35A), the symbols are defined as follows. The focal length of the first subsequent lens group GR1 is fR1. The focal length of the second subsequent lens group GR2 is fR2. The focal length of the third subsequent lens group GR3 is fR3. 0.2 <fR1 / (-fR2)<1 (28A) 0.2 <fR2 / fR3<1 (35A)

[0214] By ensuring that the corresponding value of conditional formula (28A) is not below the lower limit, the refractive power of the second subsequent lens group GR2 does not become too weak, which is advantageous for suppressing aberration fluctuations during zooming. By ensuring that the corresponding value of conditional formula (28A) is not above the upper limit, the refractive power of the first subsequent lens group GR1 does not become too weak, which is advantageous for suppressing spherical aberration at the telephoto end.

[0215] In order to obtain better characteristics, it is preferable to replace the lower limit of 0.2 in condition (28A) with any of 0.3, 0.4, 0.45, or 0.5, and it is also preferable to replace the upper limit of 1 in condition (28A) with any of 0.9, 0.8, 0.75, or 0.7.

[0216] By ensuring that the corresponding value of condition (35A) is not below the lower limit, the refractive power of the third subsequent lens group GR3 does not become too weak, which is advantageous for correcting spherical aberration at the telephoto end. By ensuring that the corresponding value of condition (35A) is not above the upper limit, the refractive power of the second subsequent lens group GR2 does not become too weak, which is advantageous for suppressing aberration fluctuations during zooming.

[0217] In order to obtain better characteristics, it is preferable to replace the lower limit of 0.2 in condition (35A) with any of 0.3, 0.4, 0.45, or 0.5, and it is also preferable to replace the upper limit of 1 in condition (35A) with any of 0.9, 0.8, 0.75, or 0.7.

[0218] The rear group GR may be configured to include an Lp1 lens having positive refractive power and an Ln1 lens having negative refractive power arranged adjacent to the image side of the Lp1 lens. The image side surface of the Lp1 lens may be configured to have an aspheric shape in which the refractive power at the position of the maximum effective diameter is shifted in the negative direction compared to the refractive power in the paraxial region. The object side surface of the Ln1 lens may be configured to have an aspheric shape in which the refractive power at the position of the maximum effective diameter is shifted in the positive direction compared to the refractive power in the paraxial region. By arranging such an Lp1 lens and an Ln1 lens in the rear group GR, it is advantageous to suppress the fluctuation of astigmatism during magnification.

[0219] The rear group GR may be configured to include an Ln2 lens having negative refractive power and an Lp2 lens having positive refractive power arranged adjacent to the image side of the Ln2 lens. The object side surface of the Ln2 lens may be configured to have an aspheric shape in which the refractive power at the position of the maximum effective diameter is shifted in the negative direction compared to the refractive power in the paraxial region. The image side surface of the Ln2 lens may be configured to have an aspheric shape in which the refractive power at the position of the maximum effective diameter is shifted in the positive direction compared to the refractive power in the paraxial region. By arranging such an Ln2 lens and an Lp2 lens in the rear group GR, it is advantageous to suppress the fluctuation of astigmatism during magnification.

[0220] The above-mentioned "position of the maximum effective diameter" will be described with reference to FIG. 3. FIG. 3 is an explanatory diagram. In FIG. 3, the left side is the object side, and the right side is the image side. FIG. 3 shows an on-axis light beam Xa and an off-axis light beam Xb passing through the lens Lx. In the example of FIG. 3, the light beam Xb1, which is the upper light beam of the off-axis light beam Xb, is the light beam that passes through the outermost side. The "outside" here means the radially outer side centered on the optical axis Z, that is, the side away from the optical axis Z. In this specification, the position of the intersection between this outermost light beam and the lens surface is the position Px of the maximum effective diameter. Also, twice the distance from the position Px of the maximum effective diameter to the optical axis Z is the effective diameter ED of the object-side surface of the lens Lx. In the example of FIG. 3, the upper light beam of the off-axis light beam Xb is the light beam that passes through the outermost side, but which light beam passes through the outermost side varies depending on the optical system.

[0221] The above phrase "refractive power at the position of the maximum effective diameter is shifted in the negative direction compared to the refractive power in the paraxial region" has the following meaning based on the sign of the refractive power. When the surface has negative refractive power in both the paraxial region and the position of the maximum effective diameter, it means that the surface has a stronger negative refractive power at the position of the maximum effective diameter compared to the paraxial region. When the surface has positive refractive power in both the paraxial region and the position of the maximum effective diameter, it means that the surface has a weaker positive refractive power at the position of the maximum effective diameter compared to the paraxial region. When the surface has refractive powers of opposite signs in the paraxial region and the position of the maximum effective diameter, it means that the surface has positive refractive power in the paraxial region and negative refractive power at the position of the maximum effective diameter.

[0222] Similarly, the above phrase "the refractive power at the position of the maximum effective diameter is shifted in the positive direction compared to the refractive power in the paraxial region" has the following meaning based on the sign of the refractive power. When the surface has positive refractive power in both the paraxial region and the position of the maximum effective diameter, it means that the surface has a stronger positive refractive power at the position of the maximum effective diameter compared to the paraxial region. When the surface has negative refractive power in both the paraxial region and the position of the maximum effective diameter, it means that the surface has a weaker negative refractive power at the position of the maximum effective diameter compared to the paraxial region. When the surface has refractive powers of opposite signs in the paraxial region and the position of the maximum effective diameter, it means that the surface has negative refractive power in the paraxial region and positive refractive power at the position of the maximum effective diameter.

[0223] The above-mentioned preferred and possible configurations can be arbitrarily combined within a range not causing any contradiction, and it is preferable that they are appropriately and selectively adopted according to the required specifications.

[0224] As an example, a preferred embodiment of the variable magnification optical system of the present disclosure comprises, in order from the object side to the image side, a front group GF, a middle group GM, and a rear group GR, wherein the front group GF consists of two or less lens groups having positive refractive power, the middle group GM consists of two or less lens groups having negative refractive power, the rear group GR consists of a plurality of lens groups, the lens group closest to the object in the rear group GR has positive refractive power, and during magnification variation, the lens group closest to the object in the front group GF moves and all of the spacings between adjacent lens groups change, satisfying the above conditional expressions (1), (2), and (3).

[0225] Next, examples of the variable magnification optical system of the present disclosure will be described with reference to the drawings. Note that the reference symbols attached to each group in the cross-sectional views of each example are used independently for each example to avoid the explanation and the drawings becoming complicated due to the increase in the number of digits of the reference symbols. Therefore, even if common reference symbols are attached in the drawings of different examples, they do not necessarily have the same configuration.

[0226] [Example 1] The configuration and movement locus of the variable magnification optical system of Example 1 are shown in FIG. 1, and the method of illustration and the configuration are as described above, so some overlapping explanations will be omitted here. The variable magnification optical system of Example 1 is composed of a front group GF, a middle group GM, and a rear group GR, in order from the object side to the image side. The front group GF is composed of one lens group having positive refractive power. The middle group GM is composed of one lens group having negative refractive power. The rear group GR is composed of a first rear lens group GR1 having positive refractive power, a second rear lens group GR2 having negative refractive power, and a third rear lens group GR3 having positive refractive power, in order from the object side to the image side.

[0227] When changing magnification from the wide-angle end to the telephoto end, the third subsequent lens group GR3 is fixed with respect to the image surface Sim, and the other lens groups move while changing the spacing between adjacent lens groups. The variable magnification optical system includes only one focusing group. The focusing group is made up of the second subsequent lens group GR2. When focusing from an object at infinity to the nearest object, the second subsequent lens group GR2 moves toward the image side, and the other lens groups are fixed with respect to the image surface Sim. The vibration reduction group is made up of the intermediate group GM.

[0228] For the variable magnification optical system of Example 1, Table 1 shows basic lens data, Table 2 shows specifications and variable surface spacing, and Table 3 shows aspheric coefficients.

[0229] The basic lens data table is written as follows. The Sn column shows the surface numbers, with the surface closest to the object being surface 1 and the numbers increasing by one toward the image side. The R column shows the radius of curvature of each surface. The D column shows the surface spacing on the optical axis between each surface and its adjacent surface on the image side. The Nd column shows the refractive index of each lens for the d-line. The νd column shows the Abbe number of each lens based on the d-line. The θgF column shows the partial dispersion ratio between the g-line and F-line of each lens. The ρ column shows the specific gravity of each lens in the front group GF, with information about other lenses being omitted.

[0230] If the refractive indices of a lens for the g-line, F-line, and C-line are Ng, NF, and NC, respectively, and the partial dispersion ratio of the lens between the g-line and F-line is θgF, then θgF is defined by the following equation. θgF=(Ng-NF) / (NF-NC)

[0231] The terms "d-line," "C-line," "F-line," and "g-line" used in this specification are emission lines, and the wavelength of the d-line is 587.56 nm (nanometers), the wavelength of the C-line is 656.27 nm (nanometers), the wavelength of the F-line is 486.13 nm (nanometers), and the wavelength of the g-line is 435.84 nm (nanometers).

[0232] In the basic lens data table, the sign of the radius of curvature of a surface with a convex shape facing the object side is positive, and the sign of the radius of curvature of a surface with a convex shape facing the image side is negative. In Table 1, the surface number and the term (St) are entered in the column for the surface number corresponding to the aperture stop St. The value in the bottom row of the D column in the table is the distance between the surface closest to the image side in the table and the image plane Sim. The symbol DD[ ] is used for the variable surface distance when varying magnification, and the surface number of this distance on the object side is entered in the [ ] in the surface distance column.

[0233] Table 2 shows the zoom ratio Zr, focal length f, back focus Bf, maximum F-number FNo., maximum full angle of view 2ω, and variable surface spacing based on the d-line. When the variable magnification optical system is a zoom lens, the zoom ratio is synonymous with the zoom magnification. [°] in the 2ω column indicates that the unit is degrees. In Table 2, the columns labeled "Wide," "Middle," and "Tele" show the values ​​for the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively.

[0234] In the basic lens data, the surface numbers of aspheric surfaces are marked with an *, and the value of the paraxial radius of curvature is given in the column for the radius of curvature of the aspheric surface. In Table 3, the Sn row shows the surface numbers of the aspheric surfaces, and the KA and Am rows show the numerical values ​​of the aspheric coefficients for each aspheric surface. Note that m in Am is an integer of 3 or more, and differs depending on the surface. For example, for the 6th surface in Example 1, m = 3, 4, 5, ..., 16. The numerical values ​​of the aspheric coefficients in Table 3, "E±n" (n: integer), are expressed as "×10 ±n " KA and Am are aspheric coefficients in the aspheric equation expressed below. Zd = C × h 2 / {1+(1-KA×C 2 ×h 2 ) 1 / 2}+ΣAm×h m however, Zd: Aspheric depth (the length of the perpendicular line drawn from a point on the aspheric surface at height h to a plane perpendicular to the optical axis Z where the apex of the aspheric surface is in contact) h: Height (distance from optical axis Z to lens surface) C: Reciprocal of paraxial curvature radius KA, Am: Aspheric coefficients In the aspheric surface formula, Σ means the summation with respect to m.

[0235] In the data in each table, the angle unit is degrees and the length unit is millimeters, but since the optical system can be used with proportional enlargement or reduction, other appropriate units can be used. Also, in each table shown below, values ​​are rounded to a predetermined number of decimal places.

[0236] [Table 1]

[0237] [Table 2]

[0238] [Table 3]

[0239] FIG. 4 shows each aberration diagram of the variable magnification optical system of Example 1 in a state where the optical system is focused on an object at infinity. In FIG. 4, from the left, spherical aberration, astigmatism, distortion, and lateral chromatic aberration are shown. In FIG. 4, the upper row labeled "Wide" shows the aberration in the wide-angle end state, the middle row labeled "Middle" shows the aberration in the intermediate focal length state, and the lower row labeled "Tele" shows the aberration in the telephoto end state. In the spherical aberration diagram, the aberrations at the d-line, C-line, and F-line are shown by solid lines, long dashed lines, and short dashed lines, respectively. In the astigmatism diagram, the aberration at the d-line in the sagittal direction is shown by solid lines, and the aberration at the d-line in the tangential direction is shown by short dashed lines. In the distortion diagram, the aberration at the d-line is shown by solid lines. In the lateral chromatic aberration diagram, the aberrations at the C-line and F-line are shown by long dashed lines and short dashed lines, respectively. In the spherical aberration diagram, the maximum F-number is shown after FNo. =. In the other aberration diagrams, the maximum half angle of view is shown after ω =.

[0240] The symbols, meanings, description methods, and illustration methods of each piece of data related to the above-mentioned Example 1 are basically the same in the following Examples unless otherwise specified, so duplicated explanations will be omitted below.

[0241] [Example 2] The configuration and movement locus of the variable magnification optical system of Example 2 are shown in FIG. 5. The variable magnification optical system of Example 2 is composed of, in order from the object side to the image side, a front group GF, an intermediate group GM, and a rear group GR. The front group GF is composed of, in order from the object side to the image side, a first front lens group GF1 having positive refractive power, and a second front lens group GF2 having positive refractive power. The intermediate group GM is composed of one lens group having negative refractive power. The rear group GR is composed of, in order from the object side to the image side, a first rear lens group GR1 having positive refractive power, a second rear lens group GR2 having positive refractive power, and a third rear lens group GR3 having negative refractive power.

[0242] When changing magnification from the wide-angle end to the telephoto end, all lens groups move while changing the spacing between adjacent lens groups. The variable magnification optical system includes only one focusing group. The focusing group is made up of the second front lens group GF2. When focusing from an object at infinity to the closest object, the second front lens group GF2 moves toward the object, and the other lens groups are fixed with respect to the image plane Sim. The vibration reduction group is made up of the intermediate group GM.

[0243] For the variable magnification optical system of Example 2, basic lens data is shown in Table 4, specifications and variable surface spacing in Table 5, aspheric coefficients in Table 6, and each aberration diagram in FIG.

[0244] [Table 4]

[0245] [Table 5]

[0246] [Table 6]

[0247] [Example 3] The configuration and movement locus of the variable magnification optical system of Example 3 are shown in FIG. 7. The variable magnification optical system of Example 3 is composed of, in order from the object side to the image side, a front group GF, a middle group GM, and a rear group GR. The front group GF is composed of one lens group having positive refractive power. The middle group GM is composed of one lens group having negative refractive power. The rear group GR is composed of, in order from the object side to the image side, a first rear lens group GR1 having positive refractive power, a second rear lens group GR2 having positive refractive power, a third rear lens group GR3 having positive refractive power, and a fourth rear lens group GR4 having negative refractive power.

[0248] When changing magnification from the wide-angle end to the telephoto end, all lens groups move while changing the spacing between adjacent lens groups. The variable magnification optical system includes only one focusing group. The focusing group is made up of the third subsequent lens group GR3. When focusing from an object at infinity to the closest object, the third subsequent lens group GR3 moves toward the object, and the other lens groups are fixed with respect to the image plane Sim. The vibration reduction group is made up of the intermediate group GM.

[0249] For the variable magnification optical system of Example 3, basic lens data is shown in Table 7, specifications and variable surface spacing in Table 8, aspheric coefficients in Table 9, and various aberration diagrams in FIG.

[0250] [Table 7]

[0251] [Table 8]

[0252] [Table 9]

[0253] [Example 4] The configuration and movement locus of the variable magnification optical system of Example 4 are shown in FIG. 9. The variable magnification optical system of Example 4 is composed of, in order from the object side to the image side, a front group GF, a middle group GM, and a rear group GR. The front group GF is composed of one lens group having positive refractive power. The middle group GM is composed of one lens group having negative refractive power. The rear group GR is composed of, in order from the object side to the image side, a first rear lens group GR1 having positive refractive power, a second rear lens group GR2 having positive refractive power, a third rear lens group GR3 having negative refractive power, and a fourth rear lens group GR4 having negative refractive power. The rear group GR includes the above-mentioned Lp1 lens and Ln1 lens.

[0254] When changing magnification from the wide-angle end to the telephoto end, the intermediate group GM is fixed with respect to the image surface Sim, and the other lens groups move while changing the spacing between adjacent lens groups. The variable magnification optical system includes only one focusing group. The focusing group is made up of the third subsequent lens group GR3. When focusing from an object at infinity to the closest object, the third subsequent lens group GR3 moves toward the image side, and the other lens groups are fixed with respect to the image surface Sim. The vibration reduction group is made up of the intermediate group GM.

[0255] For the variable magnification optical system of Example 4, basic lens data is shown in Table 10, the specifications and variable surface spacing in Table 11, the aspheric coefficients in Table 12, and each aberration diagram in Fig. 10. In the ED column of the basic lens data table, the effective diameter of each surface of the Lp1 lens and the Ln1 lens is shown, and descriptions of the other lenses are omitted.

[0256] [Table 10]

[0257] [Table 11]

[0258] [Table 12]

[0259] [Example 5] The configuration and movement locus of the variable magnification optical system of Example 5 are shown in FIG. 11. The variable magnification optical system of Example 5 is composed of, in order from the object side to the image side, a front group GF, a middle group GM, and a rear group GR. The front group GF is composed of one lens group having positive refractive power. The middle group GM is composed of one lens group having negative refractive power. The rear group GR is composed of, in order from the object side to the image side, a first rear lens group GR1 having positive refractive power, a second rear lens group GR2 having positive refractive power, a third rear lens group GR3 having negative refractive power, and a fourth rear lens group GR4 having positive refractive power. The rear group GR includes the above-mentioned Lp1 lens and Ln1 lens.

[0260] When varying magnification from the wide-angle end to the telephoto end, the second subsequent lens group GR2 and the fourth subsequent lens group GR4 are fixed with respect to the image surface Sim, and the other lens groups move while changing the spacing between adjacent lens groups. The variable magnification optical system includes only one focusing group. The focusing group is made up of the third subsequent lens group GR3. When focusing from an object at infinity to the closest object, the third subsequent lens group GR3 moves toward the image side, and the other lens groups are fixed with respect to the image surface Sim. The vibration reduction group is made up of the intermediate group GM.

[0261] For the variable power optical system of Example 5, basic lens data is shown in Table 13, specifications and variable surface spacing in Table 14, aspheric coefficients in Table 15, and each aberration diagram in Fig. 12. The ED column in the basic lens data table shows the effective diameter of each surface of the Lp1 lens and the Ln1 lens.

[0262] [Table 13]

[0263] [Table 14]

[0264] [Table 15]

[0265] [Example 6] The configuration and movement locus of the variable magnification optical system of Example 6 are shown in FIG. 13. The variable magnification optical system of Example 6 is composed of, in order from the object side to the image side, a front group GF, a middle group GM, and a rear group GR. The front group GF is composed of one lens group having positive refractive power. The middle group GM is composed of one lens group having negative refractive power. The rear group GR is composed of, in order from the object side to the image side, a first rear lens group GR1 having positive refractive power, a second rear lens group GR2 having negative refractive power, a third rear lens group GR3 having negative refractive power, and a fourth rear lens group GR4 having positive refractive power.

[0266] When changing magnification from the wide-angle end to the telephoto end, all lens groups move while changing the spacing between adjacent lens groups. The variable magnification optical system includes two focusing groups. The focusing group on the object side consists of the second subsequent lens group GR2, and the focusing group on the image side consists of the third subsequent lens group GR3. When focusing from an object at infinity to the closest object, the second subsequent lens group GR2 and the third subsequent lens group GR3 move toward the image side while changing the spacing between them, and the other lens groups are fixed with respect to the image surface Sim. The vibration reduction group consists of the intermediate group GM.

[0267] Concerning the variable magnification optical system of Example 6, basic lens data is shown in Table 16, specifications and variable surface spacing in Table 17, aspheric coefficients in Table 18, and each aberration diagram is shown in FIG.

[0268] [Table 16]

[0269] [Table 17]

[0270] [Table 18]

[0271] [Example 7] The configuration and movement locus of the variable magnification optical system of Example 7 are shown in FIG. 15. The variable magnification optical system of Example 7 is composed of, in order from the object side to the image side, a front group GF, an intermediate group GM, and a rear group GR. The front group GF is composed of one lens group having positive refractive power. The intermediate group GM is composed of, in order from the object side to the image side, a first intermediate lens group GM1 having negative refractive power, and a second intermediate lens group GM2 having negative refractive power. The rear group GR is composed of, in order from the object side to the image side, a first subsequent lens group GR1 having positive refractive power, a second subsequent lens group GR2 having negative refractive power, and a third subsequent lens group GR3 having positive refractive power.

[0272] When varying magnification from the wide-angle end to the telephoto end, the first subsequent lens group GR1 and the third subsequent lens group GR3 are fixed with respect to the image surface Sim, and the other lens groups move while changing the spacing between adjacent lens groups. The variable magnification optical system includes only one focusing group. The focusing group is made up of the second subsequent lens group GR2. When focusing from an object at infinity to the closest object, the second subsequent lens group GR2 moves toward the image side, and the other lens groups are fixed with respect to the image surface Sim. The vibration reduction group is made up of the second intermediate lens group GM2.

[0273] Concerning the variable magnification optical system of Example 7, basic lens data is shown in Table 19, specifications and variable surface spacing in Table 20, aspheric coefficients in Table 21, and each aberration diagram is shown in FIG.

[0274] [Table 19]

[0275] [Table 20]

[0276] [Table 21]

[0277] [Example 8] The configuration and movement locus of the variable magnification optical system of Example 8 are shown in FIG. 17. The variable magnification optical system of Example 8 is composed of, in order from the object side to the image side, a front group GF, an intermediate group GM, and a rear group GR. The front group GF is composed of, in order from the object side to the image side, a first front lens group GF1 having positive refractive power, and a second front lens group GF2 having positive refractive power. The intermediate group GM is composed of one lens group having negative refractive power. The rear group GR is composed of, in order from the object side to the image side, a first rear lens group GR1 having positive refractive power, a second rear lens group GR2 having positive refractive power, a third rear lens group GR3 having negative refractive power, and a fourth rear lens group GR4 having negative refractive power.

[0278] When changing magnification from the wide-angle end to the telephoto end, the fourth subsequent lens group GR4 is fixed with respect to the image surface Sim, and the other lens groups move while changing the spacing between adjacent lens groups. The variable magnification optical system includes only one focusing group. The focusing group is made up of the second front lens group GF2. When focusing from an object at infinity to the closest object, the second front lens group GF2 moves toward the object side, and the other lens groups are fixed with respect to the image surface Sim. The vibration reduction group is made up of the intermediate group GM.

[0279] Concerning the variable magnification optical system of Example 8, basic lens data is shown in Table 22, specifications and variable surface spacing in Table 23, aspheric coefficients in Table 24, and each aberration diagram in FIG.

[0280] [Table 22]

[0281] [Table 23]

[0282] [Table 24]

[0283] [Example 9] The configuration and movement locus of the variable magnification optical system of Example 9 are shown in FIG. 19. The variable magnification optical system of Example 9 is composed of, in order from the object side to the image side, a front group GF, an intermediate group GM, and a rear group GR. The front group GF is composed of, in order from the object side to the image side, a first front lens group GF1 having positive refractive power, and a second front lens group GF2 having positive refractive power. The intermediate group GM is composed of one lens group having negative refractive power. The rear group GR is composed of, in order from the object side to the image side, a first rear lens group GR1 having positive refractive power, a second rear lens group GR2 having negative refractive power, a third rear lens group GR3 having positive refractive power, and a fourth rear lens group GR4 having negative refractive power.

[0284] When varying magnification from the wide-angle end to the telephoto end, the second front lens group GF2, the first rear lens group GR1, and the third rear lens group GR3 are fixed with respect to the image surface Sim, and the other lens groups move while changing the spacing between adjacent lens groups. The variable magnification optical system includes only one focusing group. The focusing group is made up of the second rear lens group GR2. When focusing from an object at infinity to the closest object, the second rear lens group GR2 moves toward the image side, and the other lens groups are fixed with respect to the image surface Sim. The vibration reduction group is made up of the intermediate group GM.

[0285] Concerning the variable power optical system of Example 9, basic lens data is shown in Table 25, the specifications and variable surface spacing in Table 26, the aspheric coefficients in Table 27, and each aberration diagram in FIG.

[0286] [Table 25]

[0287] [Table 26]

[0288] [Table 27]

[0289] [Example 10] The configuration and movement locus of the variable magnification optical system of Example 10 are shown in FIG. 21. The variable magnification optical system of Example 10 is composed of, in order from the object side to the image side, a front group GF, an intermediate group GM, and a rear group GR. The front group GF is composed of one lens group having positive refractive power. The intermediate group GM is composed of, in order from the object side to the image side, a first intermediate lens group GM1 having negative refractive power, and a second intermediate lens group GM2 having negative refractive power. The rear group GR is composed of, in order from the object side to the image side, a first subsequent lens group GR1 having positive refractive power, a second subsequent lens group GR2 having positive refractive power, a third subsequent lens group GR3 having positive refractive power, and a fourth subsequent lens group GR4 having negative refractive power.

[0290] When changing magnification from the wide-angle end to the telephoto end, all lens groups move while changing the spacing between adjacent lens groups. The variable magnification optical system includes two focusing groups. The focusing group on the object side consists of the second subsequent lens group GR2, and the focusing group on the image side consists of the third subsequent lens group GR3. When focusing from an object at infinity to the closest object, the second subsequent lens group GR2 and the third subsequent lens group GR3 move toward the object side while changing the spacing between them, and the other lens groups are fixed with respect to the image plane Sim. The vibration reduction group consists of the first intermediate lens group GM1.

[0291] Concerning the variable power optical system of Example 10, basic lens data is shown in Table 28, the specifications and variable surface spacing in Table 29, the aspheric coefficients in Table 30, and each aberration diagram in FIG.

[0292] [Table 28]

[0293] [Table 29]

[0294] [Table 30]

[0295] [Example 11] The configuration and movement locus of the variable magnification optical system of Example 11 are shown in FIG. 23. The variable magnification optical system of Example 11 is composed of, in order from the object side to the image side, a front group GF, a middle group GM, and a rear group GR. The front group GF is composed of one lens group having positive refractive power. The middle group GM is composed of one lens group having negative refractive power. The rear group GR is composed of, in order from the object side to the image side, a first rear lens group GR1 having positive refractive power, a second rear lens group GR2 having positive refractive power, a third rear lens group GR3 having negative refractive power, a fourth rear lens group GR4 having positive refractive power, and a fifth rear lens group GR5 having negative refractive power. The rear group GR includes the above-mentioned Lp1 lens and Ln1 lens.

[0296] When varying magnification from the wide-angle end to the telephoto end, the second subsequent lens group GR2 and the fourth subsequent lens group GR4 are fixed with respect to the image surface Sim, and the other lens groups move while changing the spacing between adjacent lens groups. The variable magnification optical system includes only one focusing group. The focusing group is made up of the third subsequent lens group GR3. When focusing from an object at infinity to the closest object, the third subsequent lens group GR3 moves toward the image side, and the other lens groups are fixed with respect to the image surface Sim. The vibration reduction group is made up of the intermediate group GM.

[0297] For the variable power optical system of Example 11, basic lens data is shown in Table 31, specifications and variable surface spacing in Table 32, aspheric coefficients in Table 33, and each aberration diagram in Fig. 24. The ED column in the basic lens data table shows the effective diameter of each surface of the Lp1 lens and the Ln1 lens.

[0298] [Table 31]

[0299] [Table 32]

[0300] [Table 33]

[0301] [Example 12] The configuration and movement locus of the variable magnification optical system of Example 12 are shown in FIG. 25. The variable magnification optical system of Example 12 is composed of, in order from the object side to the image side, a front group GF, a middle group GM, and a rear group GR. The front group GF is composed of one lens group having positive refractive power. The middle group GM is composed of one lens group having negative refractive power. The rear group GR is composed of, in order from the object side to the image side, a first rear lens group GR1 having positive refractive power, a second rear lens group GR2 having positive refractive power, a third rear lens group GR3 having negative refractive power, a fourth rear lens group GR4 having positive refractive power, and a fifth rear lens group GR5 having negative refractive power.

[0302] When changing magnification from the wide-angle end to the telephoto end, all lens groups move while changing the spacing between adjacent lens groups. The variable magnification optical system includes two focusing groups. The focusing group on the object side consists of the third subsequent lens group GR3, and the focusing group on the image side consists of the fourth subsequent lens group GR4. When focusing from an object at infinity to the closest object, the third subsequent lens group GR3 and the fourth subsequent lens group GR4 move toward the object side while changing the spacing between them, and the other lens groups are fixed with respect to the image plane Sim. The vibration reduction group consists of the intermediate group GM.

[0303] Concerning the variable power optical system of Example 12, basic lens data is shown in Table 34, the specifications and variable surface spacing in Table 35, the aspheric coefficients in Table 36, and each aberration diagram in FIG.

[0304] [Table 34]

[0305] [Table 35]

[0306] [Table 36]

[0307] [Example 13] The configuration and movement locus of the variable magnification optical system of Example 13 are shown in FIG. 27. The variable magnification optical system of Example 13 is composed of, in order from the object side to the image side, a front group GF, a middle group GM, and a rear group GR. The front group GF is composed of one lens group having positive refractive power. The middle group GM is composed of one lens group having negative refractive power. The rear group GR is composed of, in order from the object side to the image side, a first rear lens group GR1 having positive refractive power, a second rear lens group GR2 having negative refractive power, a third rear lens group GR3 having positive refractive power, a fourth rear lens group GR4 having negative refractive power, and a fifth rear lens group GR5 having positive refractive power.

[0308] When changing magnification from the wide-angle end to the telephoto end, the intermediate group GM is fixed with respect to the image surface Sim, and the other lens groups move while changing the distance between adjacent lens groups. The variable magnification optical system includes two focusing groups. The focusing group on the object side consists of the second subsequent lens group GR2, and the focusing group on the image side consists of the fourth subsequent lens group GR4. When focusing from an object at infinity to the closest object, the second subsequent lens group GR2 moves toward the object side, the fourth subsequent lens group GR4 moves toward the image side, and the other lens groups are fixed with respect to the image surface Sim. The vibration reduction group consists of the intermediate group GM.

[0309] Concerning the variable power optical system of Example 13, basic lens data is shown in Table 37, the specifications and variable surface spacing in Table 38, the aspheric coefficients in Table 39, and each aberration diagram in FIG.

[0310] [Table 37]

[0311] [Table 38]

[0312] [Table 39]

[0313] [Example 14] The configuration and movement locus of the variable magnification optical system of Example 14 are shown in FIG. 29. The variable magnification optical system of Example 14 is composed of, in order from the object side to the image side, a front group GF, a middle group GM, and a rear group GR. The front group GF is composed of one lens group having positive refractive power. The middle group GM is composed of one lens group having negative refractive power. The rear group GR is composed of, in order from the object side to the image side, a first rear lens group GR1 having positive refractive power, a second rear lens group GR2 having negative refractive power, a third rear lens group GR3 having positive refractive power, a fourth rear lens group GR4 having negative refractive power, and a fifth rear lens group GR5 having negative refractive power.

[0314] When varying magnification from the wide-angle end to the telephoto end, the first subsequent lens group GR1 and the third subsequent lens group GR3 are fixed with respect to the image surface Sim, and the other lens groups move while changing the distance between adjacent lens groups. The variable magnification optical system includes two focusing groups. The focusing group on the object side consists of the second subsequent lens group GR2, and the focusing group on the image side consists of the fourth subsequent lens group GR4. When focusing from an object at infinity to the closest object, the second subsequent lens group GR2 moves toward the object side, the fourth subsequent lens group GR4 moves toward the image side, and the other lens groups are fixed with respect to the image surface Sim. The vibration reduction group consists of the intermediate group GM.

[0315] Concerning the variable power optical system of Example 14, basic lens data is shown in Table 40, the specifications and variable surface spacing in Table 41, the aspheric coefficients in Table 42, and each aberration diagram in FIG.

[0316] [Table 40]

[0317] [Table 41]

[0318] [Table 42]

[0319] [Example 15] The configuration and movement locus of the variable magnification optical system of Example 15 are shown in FIG. 31. The variable magnification optical system of Example 15 is composed of, in order from the object side to the image side, a front group GF, an intermediate group GM, and a rear group GR. The front group GF is composed of one lens group having positive refractive power. The intermediate group GM is composed of, in order from the object side to the image side, a first intermediate lens group GM1 having negative refractive power, and a second intermediate lens group GM2 having negative refractive power. The rear group GR is composed of, in order from the object side to the image side, a first subsequent lens group GR1 having positive refractive power, a second subsequent lens group GR2 having negative refractive power, a third subsequent lens group GR3 having positive refractive power, and a fourth subsequent lens group GR4 having negative refractive power.

[0320] When changing magnification from the wide-angle end to the telephoto end, all lens groups move while changing the spacing between adjacent lens groups. The variable magnification optical system includes two focusing groups. The focusing group on the object side consists of the second subsequent lens group GR2, and the focusing group on the image side consists of the third subsequent lens group GR3. When focusing from an object at infinity to the closest object, the second subsequent lens group GR2 and the third subsequent lens group GR3 move toward the object side while changing the spacing between them, and the other lens groups are fixed with respect to the image plane Sim. The vibration reduction group consists of the first intermediate lens group GM1.

[0321] Concerning the variable power optical system of Example 15, basic lens data is shown in Table 43, the specifications and variable surface spacing in Table 44, the aspheric coefficients in Table 45, and each aberration diagram in FIG.

[0322] [Table 43]

[0323] [Table 44]

[0324] [Table 45]

[0325] [Example 16] The configuration and movement locus of the variable magnification optical system of Example 16 are shown in FIG. 33. The variable magnification optical system of Example 16 is composed of, in order from the object side to the image side, a front group GF, an intermediate group GM, and a rear group GR. The front group GF is composed of, in order from the object side to the image side, a first front lens group GF1 having positive refractive power, and a second front lens group GF2 having positive refractive power. The intermediate group GM is composed of one lens group having negative refractive power. The rear group GR is composed of, in order from the object side to the image side, a first rear lens group GR1 having positive refractive power, a second rear lens group GR2 having positive refractive power, a third rear lens group GR3 having negative refractive power, a fourth rear lens group GR4 having positive refractive power, and a fifth rear lens group GR5 having negative refractive power.

[0326] When varying magnification from the wide-angle end to the telephoto end, the second subsequent lens group GR2 and the fourth subsequent lens group GR4 are fixed with respect to the image surface Sim, and the other lens groups move while changing the spacing between adjacent lens groups. The variable magnification optical system includes only one focusing group. The focusing group is made up of the third subsequent lens group GR3. When focusing from an object at infinity to the closest object, the third subsequent lens group GR3 moves toward the image side, and the other lens groups are fixed with respect to the image surface Sim. The vibration reduction group is made up of the intermediate group GM.

[0327] Concerning the variable power optical system of Example 16, basic lens data is shown in Table 46, the specifications and variable surface spacing in Table 47, the aspheric coefficients in Table 48, and each aberration diagram in FIG.

[0328] [Table 46]

[0329] [Table 47]

[0330] [Table 48]

[0331] [Example 17] The configuration and movement locus of the variable magnification optical system of Example 17 are shown in FIG. 35. The variable magnification optical system of Example 17 is composed of, in order from the object side to the image side, a front group GF, a middle group GM, and a rear group GR. The front group GF is composed of one lens group having positive refractive power. The middle group GM is composed of one lens group having negative refractive power. The rear group GR is composed of, in order from the object side to the image side, a first rear lens group GR1 having positive refractive power, a second rear lens group GR2 having negative refractive power, a third rear lens group GR3 having positive refractive power, a fourth rear lens group GR4 having negative refractive power, a fifth rear lens group GR5 having positive refractive power, and a sixth rear lens group GR6 having negative refractive power.

[0332] When varying magnification from the wide-angle end to the telephoto end, the third subsequent lens group GR3 and the fifth subsequent lens group GR5 are fixed with respect to the image surface Sim, and the other lens groups move while changing the spacing between adjacent lens groups. The variable magnification optical system includes only one focusing group. The focusing group is made up of the fourth subsequent lens group GR4. When focusing from an object at infinity to the closest object, the fourth subsequent lens group GR4 moves toward the image side, and the other lens groups are fixed with respect to the image surface Sim. The vibration reduction group is made up of the intermediate group GM.

[0333] Concerning the variable power optical system of Example 17, basic lens data is shown in Table 49, the specifications and variable surface spacing are shown in Table 50, the aspheric coefficients are shown in Table 51, and each aberration diagram is shown in FIG.

[0334] [Table 49]

[0335] [Table 50]

[0336] [Table 51]

[0337] [Example 18] The configuration and movement locus of the variable magnification optical system of Example 18 are shown in FIG. 37. The variable magnification optical system of Example 18 is composed of, in order from the object side to the image side, a front group GF, a middle group GM, and a rear group GR. The front group GF is composed of one lens group having positive refractive power. The middle group GM is composed of one lens group having negative refractive power. The rear group GR is composed of, in order from the object side to the image side, a first rear lens group GR1 having positive refractive power, a second rear lens group GR2 having negative refractive power, a third rear lens group GR3 having positive refractive power, a fourth rear lens group GR4 having negative refractive power, a fifth rear lens group GR5 having positive refractive power, and a sixth rear lens group GR6 having negative refractive power.

[0338] When varying magnification from the wide-angle end to the telephoto end, the third subsequent lens group GR3 and the fifth subsequent lens group GR5 are fixed with respect to the image surface Sim, and the other lens groups move while changing the spacing between adjacent lens groups. The variable magnification optical system includes only one focusing group. The focusing group is made up of the fourth subsequent lens group GR4. When focusing from an object at infinity to the closest object, the fourth subsequent lens group GR4 moves toward the image side, and the other lens groups are fixed with respect to the image surface Sim. The vibration reduction group is made up of the intermediate group GM.

[0339] Concerning the variable power optical system of Example 18, basic lens data is shown in Table 52, the specifications and variable surface spacing are shown in Table 53, the aspheric coefficients are shown in Table 54, and each aberration diagram is shown in FIG.

[0340] [Table 52]

[0341] [Table 53]

[0342] [Table 54]

[0343] [Example 19] The configuration and movement locus of the variable magnification optical system of Example 19 are shown in FIG. 39. The variable magnification optical system of Example 19 is composed of, in order from the object side to the image side, a front group GF, an intermediate group GM, and a rear group GR. The front group GF is composed of, in order from the object side to the image side, a first front lens group GF1 having positive refractive power, and a second front lens group GF2 having positive refractive power. The intermediate group GM is composed of one lens group having negative refractive power. The rear group GR is composed of, in order from the object side to the image side, a first rear lens group GR1 having positive refractive power, a second rear lens group GR2 having negative refractive power, a third rear lens group GR3 having positive refractive power, a fourth rear lens group GR4 having negative refractive power, and a fifth rear lens group GR5 having negative refractive power. The rear group GR includes the above-mentioned Lp1 lens, Ln1 lens, Ln2 lens, and Lp2 lens.

[0344] When varying magnification from the wide-angle end to the telephoto end, the second front lens group GF2 and the first rear lens group GR1 are fixed with respect to the image surface Sim, and the other lens groups move while changing the spacing between adjacent lens groups. The variable magnification optical system includes two focusing groups. The focusing group on the object side consists of the second rear lens group GR2, and the focusing group on the image side consists of the fourth rear lens group GR4. When focusing from an object at infinity to the closest object, the second rear lens group GR2 moves toward the object side, the fourth rear lens group GR4 moves toward the image side, and the other lens groups are fixed with respect to the image surface Sim. The vibration reduction group consists of the intermediate group GM.

[0345] For the variable power optical system of Example 19, basic lens data is shown in Table 55, specifications and variable surface spacing in Table 56, aspheric coefficients in Tables 57A and 57B, and each aberration diagram is shown in Figure 40. The column ED in the basic lens data table shows the effective diameter of each surface of the Lp1 lens, Ln1 lens, Ln2 lens, and Lp2 lens.

[0346] [Table 55]

[0347] [Table 56]

[0348] [Table 57A]

[0349] [Table 57B]

[0350] [Example 20] The configuration and movement locus of the variable magnification optical system of Example 20 are shown in FIG. 41. The variable magnification optical system of Example 20 is composed of, in order from the object side to the image side, a front group GF, an intermediate group GM, and a rear group GR. The front group GF is composed of, in order from the object side to the image side, a first front lens group GF1 having positive refractive power, and a second front lens group GF2 having positive refractive power. The intermediate group GM is composed of one lens group having negative refractive power. The rear group GR is composed of, in order from the object side to the image side, a first rear lens group GR1 having positive refractive power, a second rear lens group GR2 having negative refractive power, a third rear lens group GR3 having positive refractive power, a fourth rear lens group GR4 having negative refractive power, and a fifth rear lens group GR5 having positive refractive power. The rear group GR includes the above-mentioned Ln2 lens and Lp2 lens.

[0351] When varying the magnification from the wide-angle end to the telephoto end, the second front lens group GF2, the first subsequent lens group GR1, and the fifth subsequent lens group GR5 are fixed with respect to the image surface Sim, and the other lens groups move while changing the spacing between adjacent lens groups. The variable magnification optical system includes two focusing groups. The focusing group on the object side is made up of the second subsequent lens group GR2, and the focusing group on the image side is made up of the fourth subsequent lens group GR4. When focusing from an object at infinity to the closest object, the second subsequent lens group GR2 moves toward the object side, the fourth subsequent lens group GR4 moves toward the image side, and the other lens groups are fixed with respect to the image surface Sim. The vibration reduction group is made up of the intermediate group GM.

[0352] For the variable power optical system of Example 20, basic lens data is shown in Table 58, specifications and variable surface spacing in Table 59, aspheric coefficients in Tables 60A and 60B, and each aberration diagram in Fig. 42. The ED column in the basic lens data table shows the effective diameter of each surface of the Ln2 lens and the Lp2 lens.

[0353] [Table 58]

[0354] [Table 59]

[0355] Table 60A

[0356] [Table 60B]

[0357] [Example 21] The configuration and movement locus of the variable magnification optical system of Example 21 are shown in FIG. 43. The variable magnification optical system of Example 21 is composed of, in order from the object side to the image side, a front group GF, a middle group GM, and a rear group GR. The front group GF is composed of one lens group having positive refractive power. The middle group GM is composed of one lens group having negative refractive power. The rear group GR is composed of, in order from the object side to the image side, a first rear lens group GR1 having positive refractive power, a second rear lens group GR2 having negative refractive power, a third rear lens group GR3 having positive refractive power, a fourth rear lens group GR4 having negative refractive power, a fifth rear lens group GR5 having positive refractive power, and a sixth rear lens group GR6 having negative refractive power.

[0358] When changing magnification from the wide-angle end to the telephoto end, the sixth subsequent lens group GR6 is fixed with respect to the image surface Sim, and the other lens groups move while changing the spacing between adjacent lens groups. The variable magnification optical system includes only one focusing group. The focusing group is made up of the fourth subsequent lens group GR4. When focusing from an object at infinity to the closest object, the fourth subsequent lens group GR4 moves toward the image side, and the other lens groups are fixed with respect to the image surface Sim. The vibration reduction group is made up of the intermediate group GM.

[0359] Concerning the variable power optical system of Example 21, basic lens data is shown in Table 61, the specifications and variable surface spacing in Table 62, the aspheric coefficients in Table 63, and each aberration diagram in FIG.

[0360] [Table 61]

[0361] [Table 62]

[0362] [Table 63]

[0363] [Example 22] The configuration and movement locus of the variable magnification optical system of Example 22 are shown in FIG. 45. The variable magnification optical system of Example 22 is composed of, in order from the object side to the image side, a front group GF, an intermediate group GM, and a rear group GR. The front group GF is composed of, in order from the object side to the image side, a first front lens group GF1 having positive refractive power, and a second front lens group GF2 having positive refractive power. The intermediate group GM is composed of one lens group having negative refractive power. The rear group GR is composed of, in order from the object side to the image side, a first rear lens group GR1 having positive refractive power, a second rear lens group GR2 having negative refractive power, a third rear lens group GR3 having positive refractive power, a fourth rear lens group GR4 having negative refractive power, and a fifth rear lens group GR5 having negative refractive power.

[0364] When varying magnification from the wide-angle end to the telephoto end, the second front lens group GF2, the first rear lens group GR1, the third rear lens group GR3, and the fifth rear lens group GR5 are fixed with respect to the image surface Sim, and the other lens groups move while changing the spacing between adjacent lens groups. The variable magnification optical system includes only one focusing group. The focusing group is made up of the fourth rear lens group GR4. When focusing from an object at infinity to the closest object, the fourth rear lens group GR4 moves toward the image side, and the other lens groups are fixed with respect to the image surface Sim. The vibration reduction group is made up of the intermediate group GM.

[0365] Concerning the variable power optical system of Example 22, basic lens data is shown in Table 64, the specifications and variable surface spacing in Table 65, the aspheric coefficients in Table 66, and each aberration diagram in FIG.

[0366] [Table 64]

[0367] [Table 65]

[0368] [Table 66]

[0369] [Example 23] The configuration and movement locus of the variable magnification optical system of Example 23 are shown in FIG. 47. The variable magnification optical system of Example 23 is composed of, in order from the object side to the image side, a front group GF, an intermediate group GM, and a rear group GR. The front group GF is composed of, in order from the object side to the image side, a first front lens group GF1 having positive refractive power, and a second front lens group GF2 having positive refractive power. The intermediate group GM is composed of one lens group having negative refractive power. The rear group GR is composed of, in order from the object side to the image side, a first rear lens group GR1 having positive refractive power, a second rear lens group GR2 having negative refractive power, a third rear lens group GR3 having positive refractive power, a fourth rear lens group GR4 having negative refractive power, a fifth rear lens group GR5 having positive refractive power, and a sixth rear lens group GR6 having negative refractive power.

[0370] When varying magnification from the wide-angle end to the telephoto end, the second front lens group GF2, the first rear lens group GR1, the third rear lens group GR3, and the fifth rear lens group GR5 are fixed with respect to the image surface Sim, and the other lens groups move while changing the spacing between adjacent lens groups. The variable magnification optical system includes only one focusing group. The focusing group is made up of the fourth rear lens group GR4. When focusing from an object at infinity to the closest object, the fourth rear lens group GR4 moves toward the image side, and the other lens groups are fixed with respect to the image surface Sim. The vibration reduction group is made up of the intermediate group GM.

[0371] Concerning the variable power optical system of Example 23, basic lens data is shown in Table 67, the specifications and variable surface spacing in Table 68, the aspheric coefficients in Table 69, and each aberration diagram in FIG.

[0372] [Table 67]

[0373] [Table 68]

[0374] [Table 69]

[0375] [Example 24] The configuration and movement locus of the variable magnification optical system of Example 24 are shown in FIG. 49. The variable magnification optical system of Example 24 is composed of, in order from the object side to the image side, a front group GF, a middle group GM, and a rear group GR. The front group GF is composed of one lens group having positive refractive power. The middle group GM is composed of one lens group having negative refractive power. The rear group GR is composed of, in order from the object side to the image side, a first rear lens group GR1 having positive refractive power, a second rear lens group GR2 having positive refractive power, a third rear lens group GR3 having positive refractive power, a fourth rear lens group GR4 having negative refractive power, a fifth rear lens group GR5 having positive refractive power, and a sixth rear lens group GR6 having negative refractive power.

[0376] When varying magnification from the wide-angle end to the telephoto end, the third subsequent lens group GR3 and the fifth subsequent lens group GR5 are fixed with respect to the image surface Sim, and the other lens groups move while changing the spacing between adjacent lens groups. The variable magnification optical system includes only one focusing group. The focusing group is made up of the fourth subsequent lens group GR4. When focusing from an object at infinity to the closest object, the fourth subsequent lens group GR4 moves toward the image side, and the other lens groups are fixed with respect to the image surface Sim. The vibration reduction group is made up of the intermediate group GM.

[0377] Concerning the variable power optical system of Example 24, basic lens data is shown in Table 70, the specifications and variable surface spacing in Table 71, the aspheric coefficients in Table 72, and each aberration diagram in FIG.

[0378] [Table 70]

[0379] [Table 71]

[0380] [Table 72]

[0381] Tables 73 to 82 show values ​​corresponding to conditional formulas (1) to (35A) of the variable magnification optical systems of Examples 1 to 24. The values ​​corresponding to the examples shown in Tables 73 to 82 may be used as upper or lower limits to set preferred ranges for the conditional formulas.

[0382] [Table 73]

[0383] [Table 74]

[0384] [Table 75]

[0385] [Table 76]

[0386] [Table 77]

[0387] [Table 78]

[0388] [Table 79]

[0389] [Table 80]

[0390] [Table 81]

[0391] [Table 82]

[0392] The variable magnification optical systems of Examples 1 to 24 are constructed to be compact, yet realize a small F-number of 3.3 or less over the entire range of magnification. In particular, some Examples have an F-number of 3 or less over the entire range of magnification. Furthermore, the variable magnification optical systems of Examples 1 to 24 maintain high optical performance with various aberrations well corrected over the entire range of magnification.

[0393] Next, an imaging device according to an embodiment of the present disclosure will be described. Fig. 51 and Fig. 52 show external views of a camera 30 which is an imaging device according to an embodiment of the present disclosure. Fig. 51 shows a perspective view of the camera 30 seen from the front side, and Fig. 52 shows a perspective view of the camera 30 seen from the rear side. The camera 30 is a so-called mirrorless type digital camera, to which an interchangeable lens 20 can be removably attached. The interchangeable lens 20 is configured to include a variable magnification optical system 1 according to an embodiment of the present disclosure housed in a lens barrel.

[0394] The camera 30 includes a camera body 31, and a shutter button 32 and a power button 33 are provided on the top surface of the camera body 31. An operation unit 34, an operation unit 35, and a display unit 36 ​​are provided on the back surface of the camera body 31. The display unit 36 ​​is capable of displaying a captured image and an image within the angle of view before the image was captured.

[0395] A photographic opening through which light from a subject to be photographed enters is provided in the center of the front surface of camera body 31, and a mount 37 is provided at a position corresponding to the photographic opening, and interchangeable lens 20 is attached to camera body 31 via mount 37.

[0396] Inside the camera body 31, there are provided an imaging element such as a CCD (Charge Coupled Device) or CMOS (Complementary Metal Oxide Semiconductor) that outputs an imaging signal corresponding to the subject image formed by the interchangeable lens 20, a signal processing circuit that processes the imaging signal output from the imaging element to generate an image, and a recording medium for recording the generated image. With the camera 30, it is possible to take a still image or a video by pressing the shutter button 32, and the image data obtained by this shooting is recorded on the recording medium.

[0397] Although the technology of the present disclosure has been described above with reference to the embodiments and examples, the technology of the present disclosure is not limited to the above embodiments and examples, and various modifications are possible. For example, the radius of curvature, surface spacing, refractive index, Abbe number, aspheric coefficient, etc. of each lens are not limited to the values ​​shown in the above examples, and may take other values.

[0398] Furthermore, the imaging device according to the embodiment of the present disclosure is not limited to the above example, and can take various forms, such as a camera other than a mirrorless type, a film camera, a video camera, and a security camera.

[0399] Regarding the above-mentioned embodiments and examples, the following supplementary notes are further disclosed. [Appendix 1] The lens consists of, in order from the object side to the image side, a front group, an intermediate group, and a rear group. the front group is made up of two or less lens groups each having a positive refractive power, the intermediate group is composed of two or less lens groups each having a negative refractive power, the rear group is made up of a plurality of lens groups, the lens unit closest to the object side in the rear group has positive refractive power, During magnification change, the lens group closest to the object in the front group moves, and all the intervals between the adjacent lens groups change. TLw is the sum of the distance on the optical axis from the lens surface of the front group closest to the object side to the lens surface of the rear group closest to the image side when focused on an object at infinity at the wide-angle end, and the back focus in air equivalent distance of the entire system; The focal length of the entire system when focused on an object at infinity at the wide-angle end is fw. The maximum half angle of view when focused on an object at infinity at the wide-angle end is ωw. The back focus in the air equivalent distance of the entire system when focused on an object at infinity at the wide-angle end is Bfw, The maximum F-number when the lens is focused on an object at infinity at the telephoto end is called Fnot. TLt is the sum of the distance on the optical axis from the lens surface of the front group closest to the object side to the lens surface of the rear group closest to the image side when focused on an object at infinity at the telephoto end, and the back focus in terms of the air equivalent distance of the entire system; If the focal length of the entire system when focused on an object at infinity at the telephoto end is ft, 5 <TLw / (fw×tanωw)<12 (1) 0.5 <Bfw / (fw×tanωw)<2.5 (2) 1.8 <Fnot×(TLt / ft)<5 (3) A variable magnification optical system that satisfies conditional expressions (1), (2), and (3) expressed by the following formula: [Appendix 2] 1.9 <Fnot×(TLt / ft)<4.6 (3-1) The variable magnification optical system according to claim 1, which satisfies the conditional expression (3-1) shown below. [Appendix 3] 2 <Fnot×(TLt / ft)<4.3 (3-2) The variable magnification optical system according to claim 2, which satisfies the conditional expression (3-2) shown below. [Appendix 4] 2.2 <Fnot×(TLt / ft)<4 (3-3) The variable magnification optical system according to claim 3, which satisfies the conditional expression (3-3) shown below. [Appendix 5] 0.34<(fw×TLw×Fnot) / ft 2 <0.97 (4) 5. A variable magnification optical system according to claim 1, which satisfies conditional expression (4) represented by: [Appendix 6] 0.36<(fw×TLw×Fnot) / ft 2 <0.92 (4-1) 6. A variable magnification optical system according to claim 5, which satisfies conditional expression (4-1) shown below. [Appendix 7] 0.38<(fw×TLw×Fnot) / ft 2 <0.87 (4-2) 7. The variable magnification optical system according to claim 6, which satisfies conditional expression (4-2) shown below. [Appendix 8] 0.41<(fw×TLw×Fnot) / ft 2 <0.8 (4-3) 8. The variable magnification optical system according to claim 7, which satisfies conditional expression (4-3) shown below. [Appendix 9] If the maximum F-number when focusing on an object at infinity at the wide-angle end is Fnow, 0.075 <tanωw / Fnow<0.3 (5) 9. A variable magnification optical system according to claim 1, which satisfies conditional expression (5) shown below. [Appendix 10] 0.092 <tanωw / Fnow<0.27 (5-1) 10. The variable magnification optical system according to claim 9, which satisfies the conditional expression (5-1) shown below. [Appendix 11] 0.105 <tanωw / Fnow<0.25 (5-2) 11. The variable magnification optical system according to claim 10, which satisfies the conditional expression (5-2) shown below. [Appendix 12] 1.1 <TLt / TLw<1.9 (6) 12. A variable magnification optical system according to claim 1, which satisfies conditional expression (6) represented by: [Appendix 13] 1.15 <TLt / TLw<1.48 (6-1) 13. The variable magnification optical system according to claim 12, which satisfies the conditional expression (6-1) shown below. [Appendix 14] The focal length of the front lens group when focused on an object at infinity at the wide-angle end is fFw, If the focal length of the intermediate lens group when focused on an object at infinity at the wide-angle end is fMw, 0.8 <fFw / (-fMw)<8 (7) 14. A variable magnification optical system according to claim 1, which satisfies conditional expression (7) represented by: [Appendix 15] 1.1 <fFw / (-fMw)<5.3 (7-1) 15. The variable magnification optical system according to claim 14, which satisfies conditional expression (7-1) shown below. [Appendix 16] 0.8 <TLw / ft<1.5 (8) 16. A variable magnification optical system according to claim 1, which satisfies conditional expression (8) represented by: [Appendix 17] the rear group includes an Lp1 lens having positive refractive power, and an Ln1 lens arranged adjacent to an image side of the Lp1 lens and having negative refractive power, The image-side surface of the Lp1 lens has an aspheric shape in which the refractive power at the position of the maximum effective diameter is shifted in the negative direction compared to the refractive power in the paraxial region, 17. A variable magnification optical system according to any one of claims 1 to 16, wherein the object-side surface of the Ln1 lens has an aspheric shape in which the refractive power at the position of the maximum effective diameter is shifted in the positive direction compared to the refractive power in the paraxial region. [Appendix 18] the rear group includes an Ln2 lens having negative refractive power, and an Lp2 lens arranged adjacent to the image side of the Ln2 lens and having positive refractive power, The object side surface of the Ln2 lens has an aspheric shape in which the refractive power at the position of the maximum effective diameter is shifted in the negative direction compared to the refractive power in the paraxial region, 18. A variable magnification optical system according to any one of claims 1 to 17, wherein the image-side surface of the Ln2 lens has an aspheric shape in which the refractive power at the position of the maximum effective diameter is shifted in the positive direction compared to the refractive power in the paraxial region. [Appendix 19] 2.1 <ft / fw<6 (9) 19. A variable magnification optical system according to claim 1, which satisfies conditional expression (9) shown below. [Appendix 20] If the focal length of the lens unit closest to the object in the front group is fF1, 1.5 <fF1 / fw<12 (10) 20. A variable magnification optical system according to claim 1, which satisfies conditional expression (10) represented by: [Appendix 21] The focal length of the lens group closest to the object in the front group is fF1, If the focal length of the intermediate lens group when focused on an object at infinity at the wide-angle end is fMw, 2 <fF1 / (-fMw)<13 (11) 21. A variable magnification optical system according to claim 1, which satisfies conditional expression (11) shown below. [Appendix 22] If the focal length of the lens unit closest to the object in the front group is fF1, 0.7 <fF1 / (fw×ft) 1 / 2 <4.7 (12) 22. A variable magnification optical system according to claim 1, which satisfies conditional expression (12) represented by: [Appendix 23] If the focal length of the intermediate lens group when focused on an object at infinity at the wide-angle end is fMw, 0.18<(-fMw) / (fw×ft) 1 / 2 <0.8 (13) 23. A variable magnification optical system according to claim 1, which satisfies conditional expression (13) shown below. [Appendix 24] If the focal length of the lens unit closest to the object in the front group is fF1, 1.3 <fF1 / (ft / Fnot)<8 (14) 24. A variable magnification optical system according to claim 1, which satisfies conditional expression (14) represented by: [Appendix 25] 1.75 <fF1 / (ft / Fnot)<2.7 (14-1) The variable magnification optical system according to claim 24, which satisfies the conditional expression (14-1) shown below. [Appendix 26] the variable magnification optical system includes an aperture stop on the image side of the lens surface of the intermediate group that is closest to the image side, DDL1STw is the distance on the optical axis from the lens surface of the front group closest to the object to the aperture stop when focused on an object at infinity at the wide-angle end, If the focal length of the lens unit closest to the object in the front group is fF1, 0.1 <DDL1STw / fF1<0.9 (15) 26. A variable magnification optical system according to claim 1, which satisfies condition (15) shown below. [Appendix 27] the variable magnification optical system includes an aperture stop, When the distance on the optical axis from the lens surface of the front group closest to the object to the aperture stop in a state in which the lens is focused on an object at infinity at the wide-angle end is DDL1STw, 0.18 <DDL1STw / TLw<0.75 (16) 27. A variable magnification optical system according to claim 1, which satisfies conditional expression (16) shown below. [Appendix 28] If the focal length of the rear lens group when focused on an object at infinity at the wide-angle end is fRw, 0.7 <fw / fRw<3 (17) 28. A variable magnification optical system according to claim 1, which satisfies condition (17) shown below. [Appendix 29] If the focal length of the rear group when focused on an object at infinity at the telephoto end is fRt, 1.1 <ft / fRt<7 (18) 29. A variable magnification optical system according to claim 1, which satisfies condition (18) shown below. [Appendix 30] If the focal length of the lens unit closest to the object in the rear group is fR1, 0.05 <fR1 / (fw×ft) 1 / 2 <3 (19) 30. A variable magnification optical system according to claim 1, which satisfies condition (19) shown below. [Appendix 31] If the focal length of the lens unit closest to the object in the rear group is fR1, 0.05 <fw / fR1<2.5 (20) 31. The variable magnification optical system according to claim 1, which satisfies condition (20) shown below. [Appendix 32] 32. The variable magnification optical system according to claim 1, wherein at least one lens group that does not move during magnification variation is disposed between the front group and the lens group closest to the image side of the rear group. [Appendix 33] a vibration reduction group that moves in a direction intersecting with the optical axis during image blur correction is disposed on the image side of the front group; If the focal length of the image stabilization group is fIS, 0.07<|fIS / ft|<0.5 (21) 33. A variable magnification optical system according to claim 1, which satisfies condition (21) shown below: [Appendix 34] 34. The variable magnification optical system according to claim 33, wherein the vibration reduction group is disposed in the intermediate group. [Appendix 35] 2. The variable magnification optical system according to claim 1, wherein a focusing group that moves along the optical axis during focusing is disposed only in the rear group. [Appendix 36] 36. The variable magnification optical system according to claim 35, wherein the two focusing groups are disposed in the rear group. [Appendix 37] the front group includes a cemented lens in which a negative meniscus lens having a convex surface directed toward the object side and a positive lens having a convex surface directed toward the object side are cemented together in this order from the object side, The refractive index of the negative meniscus lens with respect to the d line is Ndn, When the Abbe number of the negative meniscus lens based on the d line is νdn, 1.94 <Ndn+0.01×νdn<2.5 (22) 37. A variable magnification optical system according to claim 1, which satisfies condition (22) represented by the following formula (22): [Appendix 38] The refractive index of the positive lens with respect to the d-line is Ndp, When the Abbe number of the positive lens based on the d line is νdp, 2 <Ndp+0.01×νdp<2.6 (23) 38. A variable magnification optical system according to claim 37, which satisfies conditional expression (23) shown below. [Appendix 39] When the average value of the Abbe numbers of all the positive lenses in the front group based on the d-line is denoted by νdFp_ave, 55<νdFp_ave<95 (24) 39. A variable magnification optical system according to claim 1, which satisfies condition (24) shown below: [Appendix 40] The thickness of the lens group closest to the object side of the front group on the optical axis is dF1. If the focal length of the lens unit closest to the object in the front group is fF1, 0.03 <dF1 / fF1<0.35 (25) 40. A variable magnification optical system according to claim 1, which satisfies condition (25) represented by the following formula (25): [Appendix 41] If the average specific gravity of all the lenses in the front group is GFave, 2 <GFave<4.3 (26) 41. A variable magnification optical system according to claim 1, which satisfies condition (26) below: [Appendix 42] The variable magnification optical system according to any one of Appendix 1 to Appendix 41, wherein the rear group consists of, in order from the object side to the image side, a first subsequent lens group having positive refractive power, a second subsequent lens group having negative refractive power, and a third subsequent lens group having positive refractive power. [Appendix 43] The focal length of the first subsequent lens group is fR1. If the focal length of the third subsequent lens group is fR3, 0.05 <fR1 / fR3<0.6 (27) 43. The variable magnification optical system according to claim 42, which satisfies conditional expression (27) shown below. [Appendix 44] The focal length of the first subsequent lens group is fR1. If the focal length of the second subsequent lens group is fR2, 0.2 <fR1 / (-fR2)<1 (28) 44. The variable magnification optical system according to claim 42, which satisfies conditional expression (28) represented by: [Appendix 45] The variable magnification optical system according to any one of Appendix 1 to Appendix 41, wherein the rear group consists of, in order from the object side to the image side, a first subsequent lens group having positive refractive power, a second subsequent lens group having positive refractive power, and a third subsequent lens group having negative refractive power. [Appendix 46] The focal length of the first subsequent lens group is fR1. If the focal length of the third subsequent lens group is fR3, 0.5 <fR1 / (-fR3)<1.6 (29) 46. ​​A variable magnification optical system according to claim 45, which satisfies conditional expression (29) represented by: [Appendix 47] The focal length of the second subsequent lens group is fR2. If the focal length of the third subsequent lens group is fR3, 0.8 <fR2 / (-fR3)<3 (30) 47. The variable magnification optical system according to claim 45 or 46, which satisfies conditional expression (30) represented by: [Appendix 48] The variable magnification optical system according to any one of Appendix 1 to Appendix 41, wherein the rear group includes, in order from the most object side to the image side, at least a first subsequent lens group having positive refractive power, a second subsequent lens group having positive refractive power, a third subsequent lens group having negative refractive power, and a fourth subsequent lens group having positive refractive power. [Appendix 49] The focal length of the first subsequent lens group is fR1. If the focal length of the third subsequent lens group is fR3, 0.9 <fR1 / (-fR3)<10 (29A) 49. The variable magnification optical system according to claim 48, which satisfies condition (29A) shown below. [Appendix 50] The focal length of the second subsequent lens group is fR2. If the focal length of the third subsequent lens group is fR3, 0.1 <fR2 / (-fR3)<1.8 (30A) 50. The variable magnification optical system according to claim 48 or 49, which satisfies conditional formula (30A) represented by: [Appendix 51] The focal length of the first subsequent lens group is fR1. If the focal length of the second subsequent lens group is fR2, 1.2 <fR1 / fR2<11 (31) 51. The variable magnification optical system according to claim 48, which satisfies conditional expression (31) represented by: [Appendix 52] The focal length of the second subsequent lens group is fR2. If the focal length of the fourth subsequent lens group is fR4, 0.1 <fR2 / fR4<1.5 (32) 52. The variable magnification optical system according to claim 48, which satisfies conditional expression (32) represented by: [Appendix 53] The variable magnification optical system according to any one of Appendix 1 to Appendix 41, wherein the rear group includes, in order from the most object side to the image side, at least a first subsequent lens group having positive refractive power, a second subsequent lens group having negative refractive power, a third subsequent lens group having positive refractive power, and a fourth subsequent lens group having negative refractive power. [Appendix 54] The focal length of the first subsequent lens group is fR1. If the focal length of the third subsequent lens group is fR3, 0.25 <fR1 / fR3<6 (27A) 54. The variable magnification optical system according to claim 53, which satisfies condition (27A) shown below. [Appendix 55] The focal length of the second subsequent lens group is fR2. If the focal length of the fourth subsequent lens group is fR4, 0.4 <fR2 / fR4<18 (32A) 55. The variable magnification optical system according to claim 53 or 54, which satisfies conditional formula (32A) represented by: [Appendix 56] The variable magnification optical system according to any one of Addendum 53 to Addendum 55, wherein the rear group consists of, in order from the object side to the image side, the first subsequent lens group having positive refractive power, the second subsequent lens group having negative refractive power, the third subsequent lens group having positive refractive power, the fourth subsequent lens group having negative refractive power, a fifth subsequent lens group having positive refractive power, and a sixth subsequent lens group having negative refractive power. [Appendix 57] The focal length of the third subsequent lens group is fR3. If the focal length of the fifth subsequent lens group is fR5, 0.2 <fR3 / fR5<2.5 (33) 57. The variable magnification optical system according to claim 56, which satisfies conditional expression (33) represented by: [Appendix 58] The focal length of the fourth subsequent lens group is fR4. If the focal length of the sixth subsequent lens group is fR6, 0.04 <fR4 / fR6<4 (34) 58. The variable magnification optical system according to claim 56 or 57, which satisfies conditional expression (34) represented by: [Appendix 59] The variable magnification optical system according to any one of Appendix 1 to Appendix 41, wherein the rear group includes, in order from the most object side to the image side, at least a first subsequent lens group having positive refractive power, a second subsequent lens group having positive refractive power, a third subsequent lens group having positive refractive power, and a fourth subsequent lens group having negative refractive power. [Appendix 60] The focal length of the first subsequent lens group is fR1. If the focal length of the second subsequent lens group is fR2, 0.06 <fR1 / fR2<0.7 (31A) 59. The variable magnification optical system according to claim 59, which satisfies condition (31A) shown below. [Note 61] The focal length of the second subsequent lens group is fR2. If the focal length of the third subsequent lens group is fR3, 0.5 <fR2 / fR3<11 (35) 61. The variable magnification optical system according to claim 59 or 60, which satisfies conditional expression (35) represented by: [Appendix 62] The focal length of the third subsequent lens group is fR3. If the focal length of the fourth subsequent lens group is fR4, 0.2 <fR3 / (-fR4)<3 (36) 62. A variable magnification optical system according to claim 59, which satisfies condition (36) represented by: [Appendix 63] The variable magnification optical system according to any one of Appendix 1 to Appendix 41, wherein the rear group consists of, in order from the object side to the image side, a first subsequent lens group having positive refractive power, a second subsequent lens group having positive refractive power, a third subsequent lens group having negative refractive power, and a fourth subsequent lens group having negative refractive power. [Appendix 64] The focal length of the first subsequent lens group is fR1. If the focal length of the second subsequent lens group is fR2, 0.6 <fR1 / fR2<4 (31B) 64. The variable magnification optical system according to claim 63, which satisfies condition (31B) represented by: [Appendix 65] The focal length of the third subsequent lens group is fR3. If the focal length of the fourth subsequent lens group is fR4, 0.05 <fR3 / fR4<1 (37) 65. The variable magnification optical system according to claim 63 or 64, which satisfies conditional expression (37) represented by: [Note 66] The variable magnification optical system according to any one of Appendix 1 to Appendix 41, wherein the rear group includes, in order from the most object side to the image side, at least a first subsequent lens group having positive refractive power, a second subsequent lens group having negative refractive power, and a third subsequent lens group having negative refractive power. [Appendix 67] The focal length of the first subsequent lens group is fR1. If the focal length of the second subsequent lens group is fR2, 0.2 <fR1 / (-fR2)<1 (28A) 67. The variable magnification optical system according to claim 66, which satisfies conditional formula (28A) shown below. [Appendix 68] The focal length of the second subsequent lens group is fR2. If the focal length of the third subsequent lens group is fR3, 0.2 <fR2 / fR3<1 (35A) 68. The variable magnification optical system according to claim 66 or 67, which satisfies conditional formula (35A) represented by: [Appendix 69] An imaging device comprising the variable magnification optical system according to any one of claims 1 to 68. [Explanation of symbols]

[0400] 1 Variable magnification optical system 20 Interchangeable Lenses 30 Camera 31 Camera body 32 Shutter button 33 Power button 34 Control section 35 Control section 36 Display section 37 Mount Bfw back focus dF1 Thickness DDL1STw Distance ED Effective Diameter GF front group GF1 First front lens group GF2 Second front lens group GM intermediate group GM1 First intermediate lens group GM2 Second intermediate lens group GR rear group GR1 First succeeding lens group GR2 2nd lens group GR3 3rd lens group GR4 4th lens group GR5 Fifth lens group GR6 6th lens group Lx Lens Px position Sim image plane St Aperture TLt total length TLw full length Xa On-axis luminous flux Xb Off-axis luminous flux Xb1 ray Z optical axis ωw Maximum half angle of view

Claims

1. The lens consists of, in order from the object side to the image side, a front group, an intermediate group, and a rear group. the front group is composed of two or less lens groups each having a positive refractive power, the intermediate group is composed of two or less lens groups each having a negative refractive power, the rear group is made up of a plurality of lens groups, the lens unit closest to the object side in the rear group has positive refractive power, During magnification change, the lens group closest to the object in the front group moves, and all the intervals between the adjacent lens groups change. TLw is the sum of the distance on the optical axis from the lens surface of the front group closest to the object side to the lens surface of the rear group closest to the image side when focused on an object at infinity at the wide-angle end, and the back focus in terms of the air equivalent distance of the entire system; The focal length of the entire system when focused on an object at infinity at the wide-angle end is fw. The maximum half angle of view when focused on an object at infinity at the wide-angle end is ωw. The back focus of the entire system in the air equivalent distance when focused on an object at infinity at the wide-angle end is Bfw, The maximum F-number when the lens is focused on an object at infinity at the telephoto end is Fnot. TLt is the sum of the distance on the optical axis from the lens surface of the front group closest to the object side to the lens surface of the rear group closest to the image side when focused on an object at infinity at the telephoto end, and the back focus in terms of the air equivalent distance of the entire system; When the focal length of the entire system at the telephoto end is focused on an object at infinity, ft is expressed as follows: 5<TLw / (fw×tanωw)<12 (1) 0.5<Bfw / (fw×tanωw)<2.5 (2) 1.8<Fnot×(TLt / ft)<5 (3) A variable magnification optical system that satisfies conditional expressions (1), (2), and (3) expressed by the following formula:

2. 1.9<Fnot×(TLt / ft)<4.6 (3-1) 2. The variable magnification optical system according to claim 1, which satisfies the conditional expression (3-1) expressed by:

3. 2<Fnot×(TLt / ft)<4.3 (3-2) 3. The variable magnification optical system according to claim 2, which satisfies the conditional expression (3-2) expressed by:

4. 2.2<Fnot×(TLt / ft)<4 (3-3) 4. The variable magnification optical system according to claim 3, which satisfies the conditional expression (3-3) expressed by:

5. 0.34<(fw×TLw×Fnot) / ft ２ <0.97 (4) 2. The variable magnification optical system according to claim 1, which satisfies conditional expression (4) expressed by:

6. 0.36<(fw×TLw×Fnot) / ft ２ <0.92 (4-1) 6. The variable magnification optical system according to claim 5, which satisfies the conditional expression (4-1) expressed by:

7. 0.38<(fw×TLw×Fnot) / ft ２ <0.87 (4-2) 7. The variable magnification optical system according to claim 6, which satisfies the conditional expression (4-2) represented by:

8. 0.41<(fw×TLw×Fnot) / ft ２ <0.8 (4-3) 8. The variable magnification optical system according to claim 7, which satisfies the conditional expression (4-3) represented by:

9. When the maximum F-number at the wide-angle end is Fnow and the lens is focused on an object at infinity, 0.075<tanωw / Fnow<0.3 (5) 2. The variable magnification optical system according to claim 1, which satisfies conditional expression (5) expressed by:

10. 0.092<tanωw / Fnow<0.27 (5-1) 10. The variable magnification optical system according to claim 9, which satisfies the conditional expression (5-1) expressed by:

11. 0.105<tanωw / Fnow<0.25 (5-2) 11. The variable magnification optical system according to claim 10, which satisfies conditional expression (5-2) expressed by:

12. 1.1<TLt / TLw<1.9 (6) 2. The variable magnification optical system according to claim 1, which satisfies conditional expression (6) expressed as follows:

13. 1.15<TLt / TLw<1.48 (6-1) 13. The variable magnification optical system according to claim 12, which satisfies the conditional expression (6-1) expressed by:

14. 2.2<Fnot×(TLt / ft)<4 (3-3) 13. The variable magnification optical system according to claim 12, which satisfies the conditional expression (3-3) represented by:

15. 0.41<(fw×TLw×Fnot) / ft ２ <0.8 (4-3) 15. The variable magnification optical system according to claim 14, which satisfies conditional expression (4-3) expressed by:

16. 0.105<tanωw / Fnow<0.25 (5-2) 16. The variable magnification optical system according to claim 15, which satisfies the conditional expression (5-2) expressed by:

17. The focal length of the front lens group when focused on an object at infinity at the wide-angle end is fFw, When the focal length of the intermediate lens group when focused on an object at infinity at the wide-angle end is fMw, 0.8<fFw / (-fMw)<8 (7) 4. The variable magnification optical system according to claim 3, which satisfies conditional expression (7) expressed as follows:

18. 1.1<fFw / (-fMw)<5.3 (7-1) 18. The variable magnification optical system according to claim 17, which satisfies the conditional expression (7-1) represented by:

19. 0.8<TLw / ft<1.5 (8) 19. The variable magnification optical system according to claim 18, which satisfies conditional expression (8) expressed by:

20. 1.15<TLt / TLw<1.48 (6-1) 20. The variable magnification optical system according to claim 19, which satisfies conditional expression (6-1) represented by:

21. 0.38<(fw×TLw×Fnot) / ft ２ <0.87 (4-2) 21. The variable magnification optical system according to claim 20, which satisfies conditional expression (4-2) expressed by:

22. 0.092<tanωw / Fnow<0.27 (5-1) 22. The variable magnification optical system according to claim 21, which satisfies the conditional expression (5-1) represented by:

23. 0.36<(fw×TLw×Fnot) / ft ２ <0.92 (4-1) 3. The variable magnification optical system according to claim 2, which satisfies the conditional expression (4-1) expressed by:

24. 0.092<tanωw / Fnow<0.27 (5-1) 24. The variable magnification optical system according to claim 23, which satisfies the conditional expression (5-1) represented by:

25. 0.105<tanωw / Fnow<0.25 (5-2) 24. The variable magnification optical system according to claim 23, which satisfies conditional expression (5-2) expressed by:

26. the rear group includes an Lp1 lens having positive refractive power, and an Ln1 lens arranged adjacent to an image side of the Lp1 lens and having negative refractive power, The image-side surface of the Lp1 lens has an aspheric shape in which the refractive power at the position of the maximum effective diameter is shifted in the negative direction compared to the refractive power in the paraxial region, 26. The variable magnification optical system according to claim 25, wherein the object side surface of the Ln1 lens has an aspheric shape in which the refractive power at the position of the maximum effective diameter is shifted in the positive direction compared to the refractive power in the paraxial region.

27. the rear group includes an Ln2 lens having negative refractive power, and an Lp2 lens arranged adjacent to the image side of the Ln2 lens and having positive refractive power, The object side surface of the Ln2 lens has an aspheric shape in which the refractive power at the position of the maximum effective diameter is shifted in the negative direction compared to the refractive power in the paraxial region, 25. The variable magnification optical system according to claim 24, wherein the image side surface of the Ln2 lens has an aspheric shape in which the refractive power at the position of the maximum effective diameter is shifted in a positive direction compared to the refractive power in the paraxial region.

28. 2.1<ft / fw<6 (9) 2. The variable magnification optical system according to claim 1, which satisfies conditional expression (9) expressed as follows:

29. If the focal length of the lens unit closest to the object side in the front group is fF1, 1.5<fF1 / fw<12 (10) 2. The variable magnification optical system according to claim 1, which satisfies conditional expression (10) expressed as follows:

30. The focal length of the lens unit closest to the object side in the front group is fF1, When the focal length of the intermediate lens group when focused on an object at infinity at the wide-angle end is fMw, 2<fF1 / (-fMw)<13 (11) 2. The variable magnification optical system according to claim 1, which satisfies the conditional expression (11) expressed as follows:

31. If the focal length of the lens unit closest to the object side in the front group is fF1, 0.7<fF1 / (fw×ft) １／２ <4.7 (12) 2. The variable magnification optical system according to claim 1, which satisfies conditional expression (12) expressed as follows:

32. When the focal length of the intermediate lens group when focused on an object at infinity at the wide-angle end is fMw, 0.18<(-fMw) / (fw×ft) １／２ <0.8 (13) 2. The variable magnification optical system according to claim 1, which satisfies the conditional expression (13) expressed as follows:

33. If the focal length of the lens unit closest to the object side in the front group is fF1, 1.3<fF1 / (ft / Fnot)<8 (14) 6. The variable magnification optical system according to claim 5, which satisfies conditional expression (14) expressed as follows:

34. 1.75<fF1 / (ft / Fnot)<2.7 (14-1) 34. The variable magnification optical system according to claim 33, which satisfies the conditional expression (14-1) represented by:

35. 0.75<Bfw / (fw×tanωw)<1.84 (2-1) 35. The variable magnification optical system according to claim 34, which satisfies the conditional expression (2-1) represented by:

36. 0.092<tanωw / Fnow<0.27 (5-1) 36. The variable magnification optical system according to claim 35, which satisfies conditional expression (5-1) expressed by:

37. 1.1<TLt / TLw<1.9 (6) 37. The variable magnification optical system according to claim 36, which satisfies conditional expression (6) expressed by:

38. 0.8<TLw / ft<1.5 (8) 38. The variable magnification optical system according to claim 37, which satisfies conditional expression (8) expressed by:

39. the variable magnification optical system includes an aperture stop on the image side of the lens surface of the intermediate group that is closest to the image side, DDL1STw is the distance on the optical axis from the lens surface of the front group closest to the object to the aperture stop when the lens surface is focused on an object at infinity at the wide-angle end, If the focal length of the lens unit closest to the object side in the front group is fF1, 0.1<DDL1STw / fF1<0.9 (15) 2. The variable magnification optical system according to claim 1, which satisfies conditional expression (15) expressed as follows:

40. the variable magnification optical system includes an aperture stop, When the distance on the optical axis from the lens surface of the front group closest to the object side to the aperture stop in a state in which the lens is focused on an object at infinity at the wide-angle end is DDL1STw, 0.18<DDL1STw / TLw<0.75 (16) 2. The variable magnification optical system according to claim 1, which satisfies conditional expression (16) expressed as follows:

41. If the focal length of the rear lens group when focused on an object at infinity at the wide-angle end is fRw, 0.7<fw / fRw<3 (17) 2. The variable magnification optical system according to claim 1, which satisfies the conditional expression (17) expressed as follows:

42. If the focal length of the rear lens group when focused on an object at infinity at the telephoto end is fRt, 1.1<ft / fRt<7 (18) 2. The variable magnification optical system according to claim 1, which satisfies conditional expression (18) expressed as follows:

43. If the focal length of the lens unit closest to the object in the rear group is fR1, 0.05<fR1 / (fw×ft) １／２ <3 (19) 2. The variable magnification optical system according to claim 1, which satisfies conditional expression (19) expressed as follows:

44. If the focal length of the lens unit closest to the object in the rear group is fR1, 0.05<fw / fR1<2.5 (20) 2. The variable magnification optical system according to claim 1, which satisfies conditional expression (20) expressed as follows:

45. 2. A variable magnification optical system according to claim 1, wherein at least one lens group that does not move during magnification variation is disposed between the front group and the lens group in the rear group that is closest to the image side.

46. a vibration reduction group that moves in a direction intersecting with the optical axis during image blur correction is disposed on the image side of the front group; If the focal length of the image stabilization group is fIS, 0.07<|fIS / ft|<0.5 (21) 2. The variable magnification optical system according to claim 1, which satisfies the conditional expression (21) expressed as follows:

47. 47. The variable magnification optical system according to claim 46, wherein the vibration reduction group is disposed in the intermediate group.

48. 2. A variable magnification optical system according to claim 1, wherein a focusing group that moves along the optical axis during focusing is disposed only in the rear group.

49. 49. The variable power optical system according to claim 48, wherein the two focusing groups are disposed in the rear group.

50. the front group includes a cemented lens in which a negative meniscus lens having a convex surface directed toward the object side and a positive lens having a convex surface directed toward the object side are cemented together in this order from the object side, The refractive index of the negative meniscus lens with respect to the d-line is Ndn, When the Abbe number of the negative meniscus lens based on the d-line is νdn, 1.94<Ndn+0.01×νdn<2.5 (22) 2. The variable magnification optical system according to claim 1, which satisfies conditional expression (22) expressed by:

51. The refractive index of the positive lens with respect to the d-line is Ndp, When the Abbe number of the positive lens based on the d-line is νdp, 2<Ndp+0.01×νdp<2.6 (23) 51. The variable magnification optical system according to claim 50, which satisfies conditional expression (23) expressed by:

52. When the average value of the Abbe numbers based on the d-line of all the positive lenses in the front group is νdFp_ave, 55<νdFp_ave<95 (24) 2. The variable magnification optical system according to claim 1, which satisfies conditional expression (24) expressed as follows:

53. The thickness of the lens group closest to the object side of the front group on the optical axis is dF1. If the focal length of the lens unit closest to the object side in the front group is fF1, 0.03<dF1 / fF1<0.35 (25) 2. The variable magnification optical system according to claim 1, which satisfies conditional expression (25) expressed as follows:

54. If the average specific gravity of all the lenses in the front group is GFave, then 2<GFave<4.3 (26) 2. The variable magnification optical system according to claim 1, which satisfies conditional expression (26) expressed as follows:

55. 2. The variable magnification optical system according to claim 1, wherein the rear group comprises, in order from the object side to the image side, a first rear lens group having positive refractive power, a second rear lens group having negative refractive power, and a third rear lens group having positive refractive power.

56. The focal length of the first subsequent lens group is fR1. If the focal length of the third subsequent lens group is fR3, 0.05<fR1 / fR3<0.6 (27) 56. The variable magnification optical system according to claim 55, which satisfies conditional expression (27) represented by:

57. The focal length of the first subsequent lens group is fR1. If the focal length of the second subsequent lens group is fR2, 0.2<fR1 / (-fR2)<1 (28) 56. The variable magnification optical system according to claim 55, which satisfies conditional expression (28) represented by:

58. 2. The variable magnification optical system according to claim 1, wherein the rear group comprises, in order from the object side to the image side, a first rear lens group having positive refractive power, a second rear lens group having positive refractive power, and a third rear lens group having negative refractive power.

59. The focal length of the first subsequent lens group is fR1. If the focal length of the third subsequent lens group is fR3, 0.5<fR1 / (-fR3)<1.6 (29) 59. The variable magnification optical system according to claim 58, which satisfies conditional expression (29) represented by:

60. The focal length of the second subsequent lens group is fR2. If the focal length of the third subsequent lens group is fR3, 0.8<fR2 / (-fR3)<3 (30) 59. The variable magnification optical system according to claim 58, which satisfies conditional expression (30) expressed by:

61. 2. The variable magnification optical system according to claim 1, wherein the rear group includes, in succession from the most object side to the image side, at least a first rear lens group having positive refractive power, a second rear lens group having positive refractive power, a third rear lens group having negative refractive power, and a fourth rear lens group having positive refractive power.

62. The focal length of the first subsequent lens group is fR1. If the focal length of the third subsequent lens group is fR3, 0.9<fR1 / (-fR3)<10 (29A) 62. The variable magnification optical system according to claim 61, which satisfies conditional expression (29A) represented by:

63. The focal length of the second subsequent lens group is fR2. If the focal length of the third subsequent lens group is fR3, 0.1<fR2 / (-fR3)<1.8 (30A) 62. The variable magnification optical system according to claim 61, which satisfies conditional expression (30A) represented by:

64. The focal length of the first subsequent lens group is fR1. If the focal length of the second subsequent lens group is fR2, 1.2<fR1 / fR2<11 (31) 62. The variable magnification optical system according to claim 61, which satisfies conditional expression (31) represented by:

65. The focal length of the second subsequent lens group is fR2. If the focal length of the fourth subsequent lens group is fR4, 0.1<fR2 / fR4<1.5 (32) 62. The variable magnification optical system according to claim 61, which satisfies conditional expression (32) represented by:

66. 2. The variable magnification optical system according to claim 1, wherein the rear group includes, in succession from the most object side to the image side, at least a first subsequent lens group having positive refractive power, a second subsequent lens group having negative refractive power, a third subsequent lens group having positive refractive power, and a fourth subsequent lens group having negative refractive power.

67. The focal length of the first subsequent lens group is fR1. If the focal length of the third subsequent lens group is fR3, 0.25<fR1 / fR3<6 (27A) 67. The variable magnification optical system according to claim 66, which satisfies conditional expression (27A) represented by:

68. The focal length of the second subsequent lens group is fR2. If the focal length of the fourth subsequent lens group is fR4, 0.4<fR2 / fR4<18 (32A) 67. The variable magnification optical system according to claim 66, which satisfies conditional expression (32A) represented by:

69. 67. The variable magnification optical system according to claim 66, wherein the rear group consists of, in order from the object side to the image side, the first subsequent lens group having positive refractive power, the second subsequent lens group having negative refractive power, the third subsequent lens group having positive refractive power, the fourth subsequent lens group having negative refractive power, a fifth subsequent lens group having positive refractive power, and a sixth subsequent lens group having negative refractive power.

70. The focal length of the third subsequent lens group is fR3. If the focal length of the fifth subsequent lens group is fR5, 0.2<fR3 / fR5<2.5 (33) 70. The variable magnification optical system according to claim 69, which satisfies conditional expression (33) represented by:

71. The focal length of the fourth subsequent lens group is fR4. If the focal length of the sixth subsequent lens group is fR6, 0.04<fR4 / fR6<4 (34) 70. The variable magnification optical system according to claim 69, which satisfies conditional expression (34) represented by:

72. 2. The variable magnification optical system according to claim 1, wherein the rear group includes, in succession from the most object side to the image side, at least a first rear lens group having positive refractive power, a second rear lens group having positive refractive power, a third rear lens group having positive refractive power, and a fourth rear lens group having negative refractive power.

73. The focal length of the first subsequent lens group is fR1. If the focal length of the second subsequent lens group is fR2, 0.06<fR1 / fR2<0.7 (31A) 73. The variable magnification optical system according to claim 72, which satisfies conditional expression (31A) represented by:

74. The focal length of the second subsequent lens group is fR2. If the focal length of the third subsequent lens group is fR3, 0.5<fR2 / fR3<11 (35) 73. The variable magnification optical system according to claim 72, which satisfies conditional expression (35) represented by:

75. The focal length of the third subsequent lens group is fR3. If the focal length of the fourth subsequent lens group is fR4, 0.2<fR3 / (-fR4)<3 (36) 73. The variable magnification optical system according to claim 72, which satisfies conditional expression (36) expressed by:

76. 2. The variable magnification optical system according to claim 1, wherein the rear group comprises, in order from the object side to the image side, a first rear lens group having positive refractive power, a second rear lens group having positive refractive power, a third rear lens group having negative refractive power, and a fourth rear lens group having negative refractive power.

77. The focal length of the first subsequent lens group is fR1. If the focal length of the second subsequent lens group is fR2, 0.6<fR1 / fR2<4 (31B) 77. The variable magnification optical system according to claim 76, which satisfies conditional expression (31B) represented by:

78. The focal length of the third subsequent lens group is fR3. If the focal length of the fourth subsequent lens group is fR4, 0.05<fR3 / fR4<1 (37) 77. The variable magnification optical system according to claim 76, which satisfies conditional expression (37) represented by:

79. 2. The variable magnification optical system according to claim 1, wherein the rear group includes, in succession from the most object side to the image side, at least a first rear lens group having positive refractive power, a second rear lens group having negative refractive power, and a third rear lens group having negative refractive power.

80. The focal length of the first subsequent lens group is fR1. If the focal length of the second subsequent lens group is fR2, 0.2<fR1 / (-fR2)<1 (28A) 80. The variable magnification optical system according to claim 79, which satisfies conditional expression (28A) represented by:

81. The focal length of the second subsequent lens group is fR2. If the focal length of the third subsequent lens group is fR3, 0.2<fR2 / fR3<1 (35A) 80. The variable magnification optical system according to claim 79, which satisfies conditional expression (35A) represented by:

82. An imaging apparatus comprising the variable magnification optical system according to any one of claims 1 to 81.

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