Patent ID: 7633685

Claim:
A zoom lens system, in order from an object side to an image side, comprising: a first lens unit having negative optical power and moving along an optical axis during zooming, the first lens unit, in order from the object side to the image side, having a negative lens element and a positive lens element with a convex surface facing the object side; a second lens unit having positive optical power and moving along an optical axis during zooming, the second lens unit having at least three lens elements and having at least one cemented lens element; and a third lens unit having positive optical power and moving along an optical axis during zooming, wherein: a lens element located nearest to the image side in the second lens unit has positive optical power, and the following condition (3)′ is satisfied: n11>1.75 (3)′ (here, 2ω W ≧67.94) where, n11 is a refractive index of the negative lens element of the first lens unit, and 2ω W is a view angle at a wide-angle limit.