A zoom optical system comprises, in order from an object: a front lens group (GFS) having a positive refractive power; an M1 lens group (GM1) having a negative refractive power; an M2 lens group (GM2) having a positive refractive power; an RN lens group (GRN) having a negative refractive power; and a subsequent lens group (GRS). Upon zooming, the distance between the front lens group (GFS) and the M1 lens group (GM1) changes, the distance between the M1 lens group (GM1) and the M2 lens group (GM2) changes, and the distance between the M2 lens group (GM2) and the RN lens group (GRN) changes. Upon focusing from an infinite distant object to a short distant object, the RN lens group (GRN) moves.

A zoom optical system (ZL) comprises, in order from an object: a first lens group (G1) having a positive refractive power; a second lens group (G2) having a negative refractive power; a third lens group (G3) having a positive refractive power; and a subsequent lens group (GR), wherein upon zooming, a distance between the first lens group (G1) and the second lens group (G2) changes, a distance between the second lens group (G2) and the third lens group (G3) changes, and a distance between the third lens group (G3) and the subsequent lens group (GR) changes, the subsequent lens group (GR) comprises a focusing lens group that moves upon focusing, and following conditional expressions are satisfied, 3.70<f1/(f2)<5.00, 3.20<f1/f3<5.00, where f1: a focal length of the first lens group (G1), f2: a focal length of the second lens group (G2), and f3: a focal length of the third lens group (G3).

A zoom optical system (ZL) comprises, in order from an object: a first lens group (G1) having a positive refractive power; a second lens group (G2) having a negative refractive power; a third lens group (G3) having a positive refractive power; and a subsequent lens group (GR), wherein upon zooming, a distance between the first lens group (G1) and the second lens group (G2) changes, a distance between the second lens group (G2) and the third lens group (G3) changes, and a distance between the third lens group (G3) and the subsequent lens group (GR) changes, the subsequent lens group (GR) comprises a focusing lens group that moves upon focusing, and the second lens group (G2) comprises a partial group that satisfies following conditional expressions, 1.40<fvr/f2<2.30, 1.80<f1/fw<3.50 where fvr: a focal length of the partial group, f2: a focal length of the second lens group (G2), f1: a focal length of the first lens group (G1), and fw: a focal length of the zoom optical system (ZL) in a wide-angle end state.

A zoom optical system includes a positive first lens group, a negative second lens group disposed on an image side of the first lens group, a positive third lens group disposed on an image side of the second lens group, a negative fourth lens group disposed on an image side of the third lens group, and a final lens group disposed on an image side of the fourth lens group and closest to an image. During zooming, distances between lens groups change, and the first lens group moves along an optical axis. A negative focusing lens group is provided, and the final lens group is disposed on an image side of the focusing lens group. A negative vibration proof group of the second lens group may include, in order from an object, a negative lens, an air gap and a cemented lens of a negative lens and a positive lens. The final lens group may have negative refractive power.

A zoom lens includes a first lens group having positive refractive power, a second lens group having negative refractive power, and a rear group. The second lens group consists of a second sub-first lens group having positive or negative power, and a second sub-second lens group having negative power. The second sub-second lens group consists of, sequentially from the object side toward the image: a positive second-first lens component; a negative second-second lens component; and a negative second-third lens component. During zooming from a short focal length end to a long focal length end, a distance between the first lens group and the second lens group increases, and a distance between the second lens group and the rear group decreases. A part of the second lens group is movable in a direction perpendicular to an optical axis during correction of image blurring.

The present invention addresses a problem of providing a zoom lens which achieves a longer focal length and has a shorter optical overall length at the telephoto end, and an imaging apparatus provided with the zoom lens. In order to solve the problem, a zoom lens is configured to include, in order from the object side, a positive first lens group G1, a negative second lens group G2, a positive composite positive lens group, and a negative composite negative lens group. The composite positive lens group includes a positive third lens group G3, and is consisting of one or more lens groups having positive refractive power. The composite negative lens group includes a negative A lens group and a negative B lens group having negative refractive power. In the zoom lens, changing focal length is performed by varying distances between the lens groups, and a predetermined condition is satisfied.

A first lens group (G1) having positive refractive power, a second lens group (G2) having negative refractive power, a third lens group (G3) having positive refractive power, a fourth lens group (G4) having negative refractive power, and a fifth lens group (G5) having positive refractive power are arranged in order from an object, and zooming is performed by changing distances between each lens group, and the first lens group (G1) is composed of three or more lenses, the fourth lens group (G4) is composed of two or less lenses, and the fifth lens group (G5) is composed of two or less lenses and moves to an image surface side upon zooming from a wide angle end state to a telephoto end state, and the following conditional expression (1) is satisfied.

8.40<f1/(?f2)(1) where, f1 denotes a focal length of the first lens group (G1), and f2 denotes a focal length of the second lens group (G2).

A zoom lens includes, in order from an object side to an image side, a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, a third lens unit having a positive refractive power, a fourth lens unit having a negative refractive power, and a rear unit including at least one lens unit. In the zoom lens, the locus of movement, the focal length, the amount of displacement during zooming, and the shapes of lens surfaces are appropriately set for each lens unit.

A zoom lens ZL includes: a first lens unit L1 having a positive refractive power, a second lens unit L2 having a negative refractive power, and a third lens unit L3 having a positive refractive power, an N?1th lens unit, and an Nth lens unit, the lens units being arranged in order from an object side to an image side. The N?1th lens unit and the Nth lens unit are located on the image side with respect to an aperture stop SP.

The present invention addresses a problem of providing a zoom lens which achieves a longer focal length and has a shorter optical overall length at the telephoto end, and an imaging apparatus provided with the zoom lens. In order to solve the problem, a zoom lens is configured to include, in order from the object side, a positive first lens group G1, a negative second lens group G2, a positive composite positive lens group, and a negative composite negative lens group. The composite positive lens group includes a positive third lens group G3, and is consisting of one or more lens groups having positive refractive power. The composite negative lens group includes a negative A lens group and a negative B lens group having negative refractive power. In the zoom lens, changing focal length is performed by varying distances between the lens groups, and a predetermined condition is satisfied.