| 摘要 |
PROBLEM TO BE SOLVED: To provide a zoom lens which is suitable for an imaging apparatus using a solid state image pickup device and can easily achieve reduction in size, high magnification, and the increase of focus speed, because angle-of-view fluctuations in focusing are small.SOLUTION: A zoom lens includes, in a lens system, a first negative lens group having negative refractive power, a second negative lens group arranged closer to an image side than the first negative lens group and having negative refractive power, and a lens group A arranged to be adjacent to the image side of the second negative lens group. Only the second negative lens group is moved to the image side, to perform focusing. The zoom lens satisfies the following conditions: 1.0<&bgr;2nmax/&bgr;2nmin<1.4 (1) and (1-&bgr;2nt)×&bgr;rt<-6.0 (2), where &bgr;2nmax and &bgr;2nmin are the maximum value and the minimum value of the lateral magnification of the second negative lens group in zooming respectively, &bgr;2nt is the lateral magnification at the telephoto end of the second negative lens group, and &bgr;rt is the composite lateral magnification at the telephoto end of the lens group arranged closer to the image side than the second negative lens group. |
