Patent ID: 7177096

Claim:
A zoom lens system comprises a negative first lens group and a positive second lens group, in this order from an object, wherein said negative first lens group comprises a negative lens element and a positive lens element, in this order from the object; wherein said positive second lens group comprises a positive lens element, a negative lens element, and a positive lens element, in this order from the object; wherein at least said object-side positive lens element and said negative lens element of said positive second lens group are cemented; and wherein said zoom lens system satisfies the following conditions: 1.5 <f 2G /( f T /f W )<3.0 1 <f 2G ( m W −m T )/( f T /f W )<3 wherein f 2G designates the focal length of said positive second lens group; f T designates the focal length of the entire zoom lens system at the long focal length extremity; f W designates the focal length of the entire zoom lens system at the short focal length extremity; m W designates the lateral magnification of said positive second lens group at the short focal length extremity; and m T designates the lateral magnification of said positive second lens group at the long focal length extremity.