Patent ID: 6934091

Claim:
An imaging system comprising an image-formation lens system and a means located on the image side thereof for defining an image pickup area, wherein: said image-formation lens system is a zoom lens system comprising at least three lens groups including a lens group of positive power and a lens group of negative power, wherein zooming is carried out by varying a spacing between adjacent lens groups, and said zoom lens system comprises a total of up to 8 lenses, and satisfies the following conditions: 0.07<δ g /IH <0.23 (1) 1.8 <TeleFno/WideFno <3 (2) −8%< DTL W ,<8% (3) where δ g is a difference between rear focal positions at d- and g-lines of said zoom lens system at a telephoto end, IH is a maximum image height at an image plane, WideFno and TeleFno are F-numbers at d-line of said zoom lens system at wide-angle end and telephoto end, respectively, and DTLw is an amount of d-line distortion at an angle of view of 28.00 at the wide-angle end.