Patent ID: 8842209

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 positive optical power; a second lens unit having negative optical power; a third lens unit having positive optical power; a fourth lens unit having positive optical power; and a fifth lens unit having negative optical power, wherein the first lens unit is composed of only optical elements having optical power, in zooming from a wide-angle limit to a telephoto limit at the time of image taking, at least the first lens unit is fixed with respect to an image surface, and the following condition (1) is satisfied: 0.7<| M 4G /M 5G |<11.0 (1) where, M 4G is an amount of movement of the fourth lens unit with respect to the image surface, in zooming from the wide-angle limit to the telephoto limit at the time of image taking, and M 5G is an amount of movement of the fifth lens unit with respect to the image surface, in zooming from the wide-angle limit to the telephoto limit at the time of image taking.