Patent ID: 8885265

Claim:
A zoom lens system having a plurality of lens units, each lens unit being composed of at least one lens element, the zoom lens system, in order from an object side to an image side, comprising: a first lens unit having negative optical power; a second lens unit having positive optical power; and a third lens unit having positive optical power, wherein in zooming from a wide-angle limit to a telephoto limit at a time of image taking, the first lens unit, the second lens unit, and the third lens unit are individually moved along an optical axis to vary magnification, the first lens unit is composed of two lens elements, the third lens unit is composed of one lens element, the first lens unit includes a lens element having at least one aspheric surface and positive optical power, and the following condition (1) is satisfied: 1.74 <Ir/ √{square root over ((| D L1 ×f G1 |))} (1) where D L1 is an optical axial thickness of a first lens element located on the object side in the first lens unit, f G1 is a focal length of the first lens unit, Ir is a maximum image height (Ir=f T ×tan(ω T )), f T is a focal length of the entire zoom lens system at a telephoto limit, and ω T is a half value (°) of maximum view angle at a telephoto limit.