Patent ID: 6958866

Claim:
A zoom lens system comprising a positive first lens group, a positive second lens group, a diaphragm, and a negative third lens group, in this order from an object, wherein each of said first through third lens groups move in an optical axis direction to perform zooming; wherein said positive first lens group comprises a negative lens element, and at least one positive lens element; wherein said negative lens element is positioned at the most object-side of said positive first lens group, and is provided with a concave surface on the object-side surface of said negative lens element; and wherein said zoom lens system satisfies the following conditions: −0.85 <r 1 /fW<− 0.5 45 <νp−νn 0.05 <LD 2/ fT <0.09 wherein r1 designates the radius of curvature of the object-side surface of the negative lens element in said positive first lens group; fW designates the focal length of the entire zoom lens system at the short focal length extremity; fT designates the focal length of the entire zoom lens system at the long focal length extremity; νp designates the average Abbe number of said positive lens element in said positive first lens group; νn designates the average Abbe number of said negative lens element in said positive first lens group; and LD2 designates the distance, along the optical axis in the positive second lens group, from the most object-side surface thereof to the most image-side surface thereof.