Patent ID: 7961409

Claim:
A zoom lens system comprising, in order from an object side: a first lens group having negative refractive power; a second lens group having positive refractive power; and a third lens group having negative refractive power, each distance between adjacent lens groups being variable for zooming from a wide-angle end state to a telephoto end state, the second lens group including, in order from the object side, a front group having positive refractive power, and a rear group, the front group consisting of only a cemented lens and being movable along an optical axis of the zoom lens system for focusing on the object, the first lens group being movable at first to an image side and then to the object side for zooming from the wide-angle end state to the telephoto end state, and the following conditional expressions being satisfied: 1.20< f 2/ fw< 1.90 −2.10< f 3/ fw<− 0.80 where f 2 denotes a focal length of the second lens group, f 3 denotes a focal length of the third lens group, and fw denotes a focal length of the zoom lens system in the wide-angle end state.