Patent ID: 7251080

Claim:
A zoom lens system comprises a negative first lens group, a diaphragm, and a positive second lens group, in this order from an object, wherein zooming is performed by moving said negative first lens group and said positive second lens group along an optical axis of said zoom lens system; wherein said negative first lens group comprises a negative first lens element, a negative second lens element, and a positive third lens element, in this order from the object; and wherein said zoom lens system satisfies the following conditions: 0.7 < ft/f 2 G < 1.1 3.0 <( d 12 w−d 12 t )/( ft/fw )<5.0 wherein ft designates the focal length of the entire zoom lens system at the long focal length extremity; f2G designates the focal length of said positive second lens group; d12w designates the distance between said negative first lens group and said positive second lens group at the short focal length extremity; d12w designates the distance between said negative first lens group and said positive second lens group at the short focal length extremity; d12t designates the distance between said negative first lens group and said positive second lens group at the lone focal length extremity: and fw designates the focal length of the entire zoom lens system at the short focal length extremity.