Patent ID: 7554745

Claim:
In a zoom lens that employs a lens eccentricity approach to compensate for an image blur and that has four groups of lens pieces, namely, the 1st lens group of positive refractive power, the 2nd lens group of negative refractive power, the 3rd lens group of positive refractive power, and the 4th lens group of positive refractive power arranged in series on the “closer to a subject first” basis, varying a magnification power from the wide angle view to the telephoto view causes the 1st and 2nd lens groups to separate from each other, the 2nd and 3rd lens groups to come closer to each other, and the 3rd and 4th lens groups to come closer to each other, the 4th lens group has the leading subset of lens pieces of positive refractivity closest to the subject, the leading subset including a composite lens that has a lens element of positive refractive power and a lens element of negative refractive power cemented together, the leading subset of lens pieces serving as an anti-tremor shift lens that is deviated in almost perpendicular to an axial direction to compensate for an image blur caused by a tremor of the photographer's hand, and the zoom lens satisfies the optical requirements as follows: 1.45 <f 41 /fw< 1.8 (1) where f41 is a focal length of the leading subset of lens pieces in the 4th lens group, and fw is a focal length of the lens optics as a whole in the wide-angle view mode.