| 摘要 |
The invention relates to a high-performance, high-zoom-ratio zoom lens that can be much more reduced in terms of thickness upon received at a collapsible lens mount, and an imaging system incorporating the same. The zoom lens comprises a positive first lens group G 1 , a negative second lens group G 2 , a positive third lens group G 3 and a positive fourth lens group G 4 . Upon zooming from the wide-angle end to the telephoto end, the first G 1 , the second G 2 , the third G 3 and the fourth lens group G 4 each move such that the air spacing between the first G 1 and the second lens group G 2 grows wide, the air spacing between the second G 2 and the third lens group G 3 becomes narrow, and the air spacing between the third G 3 and the fourth lens group G 4 grows wide. The zoom lens satisfies condition (1) with respect to the transverse magnification of the second lens group G 2 at the wide-angle end, and condition (2) with respect to the focal distance ratio of the zoom lens system between the wide-angle end and the telephoto end.
|
