Patent ID: 8243170

Claim:
A 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; 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 image side, and wherein the zoom lens system satisfies the following condition: 0.15 <D FWA /f W <0.30 (14) f T /f W >3.0 where, D FWA is an axial interval from the vertex of a surface on the most image side of the focusing lens unit to the aperture diaphragm, 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.