Patent ID: 8199415

Claim:
A zoom lens system comprising, in order from an object: a first lens group having a positive refractive power; a second lens group having a negative refractive power; and a third lens group having a positive refractive power; wherein the first lens group has a first-a partial lens group and a first-b partial lens group arranged on an image side of the first-a partial lens group with an air space and is constructed such that the first-b partial lens group moves along an optical axis direction upon focusing from infinity to a close-range object; wherein the third lens group comprises a third-a partial lens group having a positive refractive power and a third-b partial lens group having a negative refractive power arranged on the image side of the third-a partial lens group with an air space, and wherein the following conditional expression is satisfied: 2.0126 ≦f 1/ fw< 2.6 where f 1 denotes a focal length of the first lens group, and fw denotes a focal length of the whole system at a wide-angle end state.