Patent ID: 7079324

Claim:
A zoom lens comprising: a plurality of lens groups including a first lens group arranged on the foremost side and having negative optical power, wherein zooming is performed by moving at least one of the plurality of lens groups along a direction parallel to an optical axis of the zoom lens, wherein the first lens group is fixed during the zooming, wherein a first lens arranged on the foremost side, of the first lens group has negative refractive power, and wherein, when an Abbe constant and a partial dispersion of a material configuring the first lens are respectively represented by νdn and θg,Fn, a focal distance of the first lens group is represented by f 1 , and an air-equivalent back focus upon focusing on an infinity object is represented by bf, the following conditions are satisfied: νdn<32, 0.008<θ g,Fn −(0.644−0.00168×ν dn )<0.040, and | f 1 /bf|< 0.9.