Patent ID: 8400715

Claim:
In a variable power zoom lens of multi groups of lens pieces, namely, the 1st lens group of positive refractivity, the 2nd lens group of negative refractivity, the 3rd lens group of positive refractivity, and the 4th lens group of positive refractivity arranged in this order on the closer to objects first basis, the power is varied from the wide-angle end to the telephoto end as a result of the 1st and 2nd lens groups being separated more, the 2nd and 3rd lens groups coming closer to each other, and the 3rd and 4th lens groups also coming closer to each other, and the 3rd lens group has a leading set of lens pieces closer to the object side having a positive refractivity as a whole and a trailing set of lens pieces having a negative refractivity as a whole, and the trailing set alone are moved in position orthogonal to the optical axis to compensate for defocus in the imaging plane caused by a tremor of the user's hand(s) while the 2nd lens group is displaced closer to objects for the focusing of which requirements are to satisfy the following formula: 0.14 <|f 3 r/ft|< 0.18 (9) where f3 r is a focal length of the trailing set of the 3rd lens group, and ft is the focal length of the entire optics of the zoom lens at the telephoto end, and wherein the leading set of the 3rd lens group has three or more positive lens pieces at least one of which is a composite lens joined with a negative lens piece, and another negative lens piece(s).