| 摘要 |
A telephoto zoom lens having four lens groups in a P-N-P-P configuration arranged sequentially from an object side. The first lens group includes a front group which is fixed when focusing and has a positive refractive power, and a rear group which moves when focusing and has a positive refractive power. The entire first lens group, including the front and rear groups, is fixed during zooming, and the second and third lens groups move during zooming. The second lens group compensates for shaking of an image plane caused by hand-shaking, by moving in a direction perpendicular to the optical axis, and satisfies the following condition: 1.2<f1a/f1b<1.8 where f1a and f1b denote the focal length of the front group of the first lens group and the focal length of the rear group of the first lens group, respectively.
|
