LENS SYSTEM AND IMAGE PICKUP APPARATUS

A lens system (10) for image pickup includes, in order from an object side (11), a first lens group (G1) with positive refractive power that moves during focusing, a second lens group (G2) with positive refractive power that is disposed on an opposite side of a stop (St) to the first lens group and moves during focusing, and a third lens group (G3) with positive refractive power that is disposed closest to an image plane side (12) and is fixed. The third lens group includes, in order from the object side, a cemented lens (B31) composed of a lens with positive refractive power and a lens with negative refractive power. A combined focal length (f3) of the third lens group and a combined focal length (f12) of the first lens group and the second lens group satisfy a following condition: 2≤f3/f12≤200.