Patent ID: 7336419

Claim:
A zoom lens comprising: a first lens group having a positive refracting power and being fixed with respect to an image plane; a second lens group having a negative refracting power and being movable along an optical axis to vary a power; a third lens group having a positive refracting power and being fixed with respect to the image plane; and a fourth lens group having a positive refracting power and being movable along an optical axis; wherein said first, second, third and fourth lens groups are disposed in this order from an object side; and wherein said third lens group is vertically movable with respect to the optical axis, wherein a shifting amount Y of said third lens group at a focal length f of an entire system when correcting a movement of an image during a shaking of said zoom lens, a shifting amount Yt of said third lens group at a telephoto end, and a focal length ft of the telephoto end satisfy the following conditional expressions Yt>Y; and ( Y/Yt )/( f/ft )<1.5.