Patent ID: 7079327

Claim:
A zoom lens comprising four lens groups arranged along an optical axis in order from an object side as follows: a first lens group having positive refractive power; a second lens group having negative refractive power; a third lens group having positive refractive power; and a fourth lens group having negative refractive power; wherein the second and third lens groups move along the optical axis during zooming and the distance between the second and third lens groups changes during zooming; and the following conditions are satisfied: 0.24<f1/ft<0.29 −0.55<f2/f3<−0.44 where f 1 is the focal length of the first lens group; ft is the focal length of the entire zoom lens at the telephoto end; f 2 is the focal length of the second lens group; and f 3 is the focal length of the third lens group.