Patent ID: 8405918

Claim:
A zoom lens, wherein a first lens group having a negative refractive power, a second lens group having a positive refractive power, and a third lens group having a positive refractive power are disposed from an object side to an image side in order; when a zooming state is changed from a wide angle end state to a telescopic end state, at least said first lens group and said second lens group are movable; said first lens group is constructed in such a way that a glass lens having a negative refractive power and a plastic lens having a positive refractive power are disposed from the object side to the image side in order; said second lens group is constructed in such a way that a cemented lens composed of a glass lens having a positive refractive power and located on the object side, and a glass lens having a negative refractive power and located on the image side, and a plastic lens having a negative refractive power are disposed from the object side to the image side in order; said third lens group has at least one plastic lens having a positive refractive power; and conditional expressions (1), (2) and (3) are fulfilled: Lw /( fw ·tan ω w )<9.0 (1) | f 2/( fw·ft ) 1/2 |<1.0 (2) 1.2 <|f 1/( fw·ft ) 1/2 |<1.4 (3) where Lw is an optical total length in a wide angle end, fw is a focal length of a lens entire system in the wide angle end, ωw is a half field angle in the wide angle end, f 2 is a focal length of said second lens group, ft is a focal length of the lens entire system in a telescopic end, and f 1 is a focal length of said first lens group.