Patent ID: 7139132

Claim:
A zoom lens system comprising from the object side to the image side: a first lens unit having negative optical power, the first lens unit consisting of a first lens element having negative optical power and a second lens element having positive optical power; and a second lens unit having positive optical power, wherein the distance between the first lens unit and the second lens unit changes during zooming, and wherein a focal length of the first lens unit (f 1 ), a focal length of the first lens element (f 11 ), a focal length of the second lens element (f 12 ), an Abbe number of a material constituting the first lens element (ν 11 ), and an Abbe number of a material constituting the second lens element (ν 12 ) satisfy the following condition: - 0.6 < f11 × f12 ( f1 ) 2 < - 0.2 7 < v11 - v12 < 15 , wherein a refractive index (N 12 ) and an Abbe number (ν 12 ) of a material constituting the second lens element satisfy the following conditions: 1.9<N 12 26<[ 12 .