Patent ID: 8254036

Claim:
A zoom lens comprising: 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 positive refractive power, which are arranged in this order from the object side of the zoom lens, wherein the focal length of the entire system of the zoom lens is changed by moving, along the optical axis of the zoom lens, the second lens group and the third lens group in such a manner to change a distance therebetween, and wherein the first lens group includes two cemented lenses, each composed of a negative meniscus lens, which is a negative lens, and a positive lens cemented together in this order from the object side, and a positive lens, and the two cemented lenses and the positive lens being arranged in this order from the object side, and wherein the following formula (1) is satisfied: 0.14 <fG 1 /ft< 0.26 (1), where fG1 is the focal length of the first lens group, and ft is the focal length of the entire system at telephoto end.