ZOOM LENS SYSTEM, IMAGING APPARATUS AND CAMERA

PROBLEM TO BE SOLVED: To provide a zoom lens system, an imaging apparatus, and a camera which have high resolution as a matter of course and make it possible to reduce thickness especially when collapsed while keeping a relatively high zooming ratio.SOLUTION: The zoom lens system, the imaging apparatus, and the camera comprise, in order from an object side to an image side: a first lens group with negative power; a second lens group of positive power; a third lens group of positive power; and an aperture stop arranged on the object side of the second lens group. Power is varied by moving the first, second, and third lens groups along an optical axis when zooming takes place from a wide-angle end to a telephoto end during imaging. When the zooming takes place, the aperture stop moves integrally with the second lens group along the optical axis. The following expressions are satisfied: T/{f×tan(ω)}4.5. Here, Tis the thickness of the first lens group on the optical axis, ωis a half field angle at the telephoto end, fis the focal distance of the entire system at the telephoto end, and fis the focal distance of the entire system at the wide-angle end.