Abstract: The imaging lens includes, in order from an object side, a first lens group that has a refractive power, a second lens group that has a positive refractive power, and a third lens group that has a negative refractive power. During focusing, the second lens group moves. The second lens group includes a stop and at least three negative lenses. The imaging lens satisfies predetermined conditional expressions.

Abstract: An imaging lens consisting of, in order from an object side to an image side: a first lens group that has a positive refractive power; a second lens group that has a positive refractive power; and a third lens group, wherein: during focusing, the second lens group moves along an optical axis, and the first lens group and the third lens group remain stationary with respect to an image plane, the second lens group includes a stop, an Lp1 lens, which is a positive lens, is disposed closest to the object side in the second lens group, an Lp2 lens, which is a positive lens, is disposed closest to the image side in the second lens group.

Abstract: The zoom lens consists of, in order from an object side, a positive first lens group, a negative second lens group, a third lens group, a positive fourth lens group, and a positive fifth lens group. During zooming, the second lens group, the third lens group, and the fourth lens group move. The first lens group consists of, in order from an object side, a negative first a lens group, a positive first b lens group that moves during focusing, and a positive first c lens group. A most-image-side lens of the first b lens group is a negative meniscus lens having a convex surface facing an object side.

Abstract: The zoom lens consists of, in order from an object side, a positive first lens group, a negative second lens group, a positive third lens group, a positive fourth lens group, and a positive fifth lens group. During zooming, the second lens group, the third lens group, and the fourth lens group move. The first lens group consists of, in order from an object side, a negative first a lens group, a positive first b lens group that moves during focusing, and a positive first c lens group. The second lens group includes one positive lens and one or more negative lenses successively in order from a most object side to an image side.

Abstract: A zoom lens consisting of, in order from an object side to an image side: a first lens group that has a positive refractive power; a second lens group that has a negative refractive power; an intermediate lens group that consists of one or two lens groups; and a final lens group, wherein during zooming, the second lens group moves along an optical axis, and all distances between adjacent lens groups change.

Abstract: The variable magnification optical system includes, in order from an object side, a positive first lens group disposed at a position closest to the object side, a variable magnification lens group which is disposed at a position closest to the object side among negative lens groups and moves during changing magnification, an intermediate group including at least one lens group, and a positive final lens group which is disposed at a position closest to the image side. The variable magnification lens group, the intermediate group, and the final lens group are continuously disposed. The variable magnification optical system includes at least one LA lens. This LA lens satisfies predetermined conditional expressions relating to a refractive index, an Abbe number, and a partial dispersion ratio, and is located from the variable magnification lens group to the intermediate group.

Abstract: The imaging lens includes at least one negative lens that satisfies predetermined Conditional Expressions (1) to (3) indicating conditions in which dispersion is relatively low and refractive index is high while having a negative rate of change of the refractive index. A positive lens having a largest Abbe number at the d line among positive lenses included in the imaging lens satisfies predetermined Conditional Expressions (4) and (5).

Abstract: The zoom lens consists of, in order from the object side, a positive first lens group G1, a negative second lens group G2, a negative third lens group G3, a stop, and a positive fourth lens group G4. During zooming, the first lens group G1 and the fourth lens group G4 remain stationary, and the second lens group G2 and the third lens group G3 move. The first lens group G1 consists of, in order from the object side, a negative first lens group front group G1A that remains stationary during focusing, a positive first lens group intermediate group G1B that moves during focusing, and a positive first lens group rear group G1C that remains stationary during focusing. The following conditional expression relating to an Abbe number ?n1A2 of the second negative lens from the object side is satisfied: 65<?n1A2<110.

Abstract: The zoom lens consists of, in order from an object side, a positive first lens group, a negative second lens group, a third lens group, a positive fourth lens group, and a positive fifth lens group. During zooming, the second lens group, the third lens group, and the fourth lens group move. The first lens group consists of, in order from an object side, a negative first a lens group, a positive first b lens group that moves during focusing, and a positive first c lens group. A most-image-side lens of the first b lens group is a negative meniscus lens having a convex surface facing an object side.

Abstract: The zoom lens consists of, in order from an object side, a positive first lens group, a negative second lens group, a positive third lens group, a positive fourth lens group, and a positive fifth lens group. During zooming, the second lens group, the third lens group, and the fourth lens group move. The first lens group consists of, in order from an object side, a negative first a lens group, a positive first b lens group that moves during focusing, and a positive first c lens group. The second lens group includes one positive lens and one or more negative lenses successively in order from a most object side to an image side.

Abstract: An extender lens is removably inserted into a master lens, performs an increase in a focal length without changing an imaging position due to insertion, and consists of a positive first lens group and a negative second lens group in order from the object side. The first lens group consists of one or more positive lenses in order from the object side, and a three-lens cemented lens having three lenses of a positive lens, a negative lens, and a positive lens having cemented together in order from the object side. The following Conditional Expression (1) relating to an Abbe number ?1n of the negative lens of the three-lens cemented lens is satisfied: 26<?1n<40.

Abstract: The zoom lens consists of, in order from an object side, a first lens group having a positive power, a second lens group having a negative power, a third lens group having a negative power, a stop, a fourth lens group having a positive power, and a fifth lens group having a positive power. During zooming, the first lens group and the fifth lens group remain stationary, and the other lens groups and the stop move. The most image side positive lens is disposed to be closest to the image side in the first lens group. The following conditional expression relating to a partial dispersion ratio ?gF1p of the most image side positive lens between the g line and the F line and an Abbe number ?1p is satisfied: 0.6376<?gF1p+0.0017×?1p<0.7.

Abstract: The zoom lens consists of, in order from the object side, a first lens group that has a positive refractive power and remains stationary during zooming, a second lens group that moves during zooming, and a subsequent lens group. The first lens group has a negative lens at a position closest to the object side. The subsequent lens group has, successively in order from a position closest to the image side, a final positive lens group that remains stationary during zooming, a positive lens group that moves during zooming, a stop, and a negative lens group that moves during zooming. The stop moves integrally with the positive lens group during zooming. The stop first moves to the object side, and reversely moves during zooming from the wide-angle end to the telephoto end. Predetermined conditional expressions are satisfied.

Abstract: The variable magnification optical system includes, in order from an object side, a positive first lens group disposed at a position closest to the object side, a variable magnification lens group which is disposed at a position closest to the object side among negative lens groups and moves during changing magnification, an intermediate group including at least one lens group, and a positive final lens group which is disposed at a position closest to the image side. The variable magnification lens group, the intermediate group, and the final lens group are continuously disposed. The variable magnification optical system includes at least one LA lens. This LA lens satisfies predetermined conditional expressions relating to a refractive index, an Abbe number, and a partial dispersion ratio, and is located from the variable magnification lens group to the intermediate group.

Abstract: The imaging lens includes at least one negative lens that satisfies predetermined Conditional Expressions (1) to (3) indicating conditions in which dispersion is relatively low and refractive index is high while having a negative rate of change of the refractive index. A positive lens having a largest Abbe number at the d line among positive lenses included in the imaging lens satisfies predetermined Conditional Expressions (4) and (5).

Abstract: The zoom lens consists of, in order from an object side, a first lens group having a positive power, a second lens group having a negative power, a third lens group having a negative power, a stop, a fourth lens group having a positive power, and a fifth lens group having a positive power. During zooming, the first lens group and the fifth lens group remain stationary, and the other lens groups and the stop move. The most image side positive lens is disposed to be closest to the image side in the first lens group. The following conditional expression relating to a partial dispersion ratio ?gF1p of the most image side positive lens between the g line and the F line and an Abbe number ?1p is satisfied: 0.6376<?gF1p+0.0017×?1p<0.7.

Abstract: An extender lens is removably inserted into a master lens, performs an increase in a focal length without changing an imaging position due to insertion, and consists of a positive first lens group and a negative second lens group in order from the object side. The first lens group consists of one or more positive lenses in order from the object side, and a three-lens cemented lens having three lenses of a positive lens, a negative lens, and a positive lens having cemented together in order from the object side. The following Conditional Expression (1) relating to an Abbe number ?1n of the negative lens of the three-lens cemented lens is satisfied: 26<?1n<40.

Abstract: The zoom lens consists of, in order from the object side, a positive first lens group G1, a negative second lens group G2, a negative third lens group G3, a stop, and a positive fourth lens group G4. During zooming, the first lens group G1 and the fourth lens group G4 remain stationary, and the second lens group G2 and the third lens group G3 move. The first lens group G1 consists of, in order from the object side, a negative first lens group front group G1A that remains stationary during focusing, a positive first lens group intermediate group G1B that moves during focusing, and a positive first lens group rear group G1C that remains stationary during focusing. The following conditional expression relating to an Abbe number ?n1A2 of the second negative lens from the object side is satisfied: 65<?n1A2<110.

Abstract: The zoom lens consists of, in order from the object side, a first lens group that has a positive refractive power and remains stationary during zooming, a second lens group that moves during zooming, and a subsequent lens group. The first lens group has a negative lens at a position closest to the object side. The subsequent lens group has, successively in order from a position closest to the image side, a final positive lens group that remains stationary during zooming, a positive lens group that moves during zooming, a stop, and a negative lens group that moves during zooming. The stop moves integrally with the positive lens group during zooming. The stop first moves to the object side, and reversely moves during zooming from the wide-angle end to the telephoto end. Predetermined conditional expressions are satisfied.

Abstract: A zoom lens consists of five lens groups including, in order from the object side, positive, negative, positive, positive, and positive lens groups. During magnification change, the first and fifth lens groups are fixed relative to the image plane, and the second, third, and fourth lens groups are moved to change distances therebetween. During magnification change from the wide-angle end to the telephoto end, the second lens group is moved from the object side toward the image plane side, and the fourth lens group is moved from the image plane side toward the object side. The fifth lens group includes at least two negative lenses, and satisfies the condition expression (1) below: 1.90<LABnd??(1).