Patent ID: 8279531

Claim:
A zoom lens system comprising multiple lens elements consisting of four lens units, wherein the four lens units are, in order from an object side to an image side, a first lens unit having negative optical power, a second lens unit having positive optical power, a third lens unit having negative optical power, and a fourth lens unit having positive optical power, wherein in zooming from a wide-angle limit to a telephoto limit at the time of image taking, one or more of the four lens units are moved along an optical axis such that an air space between at least any two lens units among the four lens units is varied, so that variable magnification is achieved, wherein the first lens unit includes a lens element having a reflecting surface for bending a light beam incident from the object, and wherein the following conditions are satisfied: 0.20<| f G1 |/f T <0.52 and f T /f W ≧4.0 where, f G1 is a composite focal length of the first lens unit, f T is a focal length of the entire system at a telephoto limit, and f W is a focal length of the entire system at a wide-angle limit.