Patent ID: 7515354

Claim:
A zoom lens system comprising in order from an object side: a first lens unit having a positive refracting power; a second lens unit having a negative refracting power; and a third lens unit having a positive refracting power, wherein at a time of zooming from a wide angle end to a telephoto end, each space between the lens units changes, and the first lens unit comprises a negative lens and a positive lens, and the total number of lenses in the first lens unit is two, and the zoom lens system satisfies the following conditional expression −0.50 <SF 1p <−0.1 where, SF 1p is defined as SF 1p =(R 1pf +R 1pr )/(R 1pf −R 1pr ), when R 1pf is a paraxial radius of curvature of a surface on the object side, of the positive lens in the first lens unit, and R 1pr is a paraxial radius of curvature of a surface on an image side, of the positive lens in the first lens unit.