Patent ID: 8098983

Claim:
A zoom lens system, in order from an object side to an image side, comprising at least: a first lens unit having positive optical power; a second lens unit having negative optical power; a third lens unit having negative optical power; and an aperture diaphragm, wherein at the time of zooming, the first lens unit, the second lens unit and the third lens unit move so that intervals between these lens units vary, wherein at the time of focusing from an infinity in-focus condition to a close-point object in-focus condition, the third lens unit moves to the object side, and wherein the following condition is satisfied: 0.10<( D F /f W )*( f T /f W )<2.00 (8) (here, f T /f W )>3.0) where, D F is an axial thickness of the focusing lens unit, f T is a focal length of the entire system at a telephoto limit, and f W is focal length of the entire system at a wide-angle limit.