Patent ID: 7436601

Claim:
A zoom lens comprising, in order from an object side, a first lens group having negative refracting power, a second lens group having positive refracting power, wherein a total number of the lens groups contained in the zoom lens is two, and when magnification from a wide angle end to a telephoto end is performed, mutual interval between the first lens group and the second lens group is narrowed, and when focusing is performed from a state in which focusing to an object point from the infinite distance to an object point at a short distance is performed, the first lens group is moved to the object side, and the following conditions are satisfied, 0.930 <|f 1 |/√{square root over ( )}( f w ·f T )<0.990 L T /LW >1 1.0<(β 2w ) 2 ×f T /fw <1.20 1.2<|β 2 T |<5 where f 1 is a focal length of the first lens group, fw is a focal length of the whole system of the zoom lens when focusing is performed at the infinite object point at a wide angle end f T is a focal length of the whole system of the zoom lens when focusing is performed at the infinite object point at a telephoto end, Lw is a distance from the surface top of the surface nearest to the object side of the first lens group to an image forming surface when focusing is performed at the infinite object point at the wide angle end, L T is an actual distance from the surface top of the surface nearest to the object side of the first lens group to an image forming surface when focusing is performed at the infinite object point at the telephoto end, β 2w is lateral magnification of the second lens group when focusing to the object point at the infinite distance at the wide angle end is performed, and β 2 T is lateral magnification of the second lens group when focusing to the object point of the infinite distance at the telephoto end is performed.