Patent ID: 8614855

Claim:
A zoom lens comprising sequentially from an object side: a first lens group having a positive refractive power; a second lens group having a negative refractive power; a third lens group having a positive refractive power; a fourth lens group having a negative refractive power; and a fifth lens group having a positive refractive power and formed by a cemented lens alone, the cemented lens comprising a negative lens and a positive lens, wherein the zoom lens zooms from a wide angle edge to a telephoto edge by moving the second lens group along an optical axis, from the object side toward an image plane side, the zoom lens performs focusing and corrects image plane variation accompanying zoom by moving the fourth lens group along the optical axis, the zoom lens corrects image blur caused by minute vibrations by moving the entire fifth lens group in a direction orthogonal to the optical axis, and a conditional expression 0.06<f 5 /f t <0.08 is satisfied, where f 5 is the focal length of the fifth lens group and f t is the focal length of the entire zoom lens system, at the telephoto edge.