Patent ID: 8154801

Claim:
A zoom lens comprising, in order from an object side to an image side: a first lens group that has a positive refractive power and remains stationary in a direction of an optical axis; a second lens group that has a negative refractive power and is movable on the optical axis so as to perform a zoom operation; a third lens group that has a positive refractive power and remains stationary in the direction of the optical axis during zooming and focusing; a fourth lens group that has a positive refractive power and is movable on the optical axis so as to correct fluctuation in imaging position and correct change in imaging position caused by change in object distance; and a fifth lens group that has a positive refractive power and remains stationary in the direction of the optical axis, wherein the fifth lens group includes, in order from the object side to the image side, a first lens that has a negative refractive power and remains stationary in the direction of the optical axis, and a second lens that has a positive refractive power and is movable in a direction perpendicular to the direction of the optical axis, wherein by moving the second lens of the fifth lens group in the direction perpendicular to the direction of the optical axis, an image formed on an image plane can be shifted in the direction perpendicular to the direction of the optical axis, and wherein the following conditional expressions (1), (2), and (4) are satisfied 1.0 <f 3 /f 4<2.0, (1) 0.25<|β2 w|< 0.4, (2) and 1.1<β5<1.7, (4) where f3 is a composite focal length of the third lens group, f4 is a composite focal length of the fourth lens group, β2w is an imaging magnification of the second lens group in a wide-angle end state, β5 is an imaging magnification of the fifth lens group.