Patent ID: 7324293

Claim:
A wide-angle lens system comprises a negative front lens group and a positive rear lens group, in this order from an object, wherein said negative front lens group comprises a negative first sub-lens group and a positive second sub-lens group, in this order from the object; wherein said positive rear lens group comprises cemented lens elements having a positive R1 lens element and a negative R2 lens element, a positive R3 lens element having a convex surface facing toward the image, and a positive R4 lens element, in this order from the object; and wherein said wide-angle lens system satisfies the following conditions: −0.8 <f 1 a/f 1 b<− 0.1 0.6 <f/fR< 1.1 wherein f1a designates the focal length of said negative first sub-lens group; f1b designates the focal length of said positive second sub-lens group; f designates the focal length of the entire wide-angle lens system; and fR designates the focal length of said positive rear lens group.