| 摘要 |
A zoom lens system includes a negative first lens group, positive second and third lens groups, wherein upon zooming from the short to long focal length extremities, the distance between the first and second lens groups decreases and the distance between the second and third lens groups changes. The second lens group includes a biconvex positive lens element with an aspherical surface on each side, and a negative meniscus lens element with an aspherical surface, and a concave surface on the image side. Conditions (1) and (2) are satisfied: nud>80(1), and Pg-F>0.53(2), wherein nud designates the Abbe number at the d-line of the biconvex positive lens element within the second lens group, and Pg_F designates the partial dispersion ratio of the biconvex positive lens element within the second lens group. |
