| 摘要 |
PROBLEM TO BE SOLVED: To provide a compact, inexpensive and high-performance zoom lens for a compact camera which is composed of two groups, whose half viewing angle at a short focal distance end is nearly 35 deg. and whose zoom ratio is about 2.8. SOLUTION: This zoom lens system is composed of the positive and the negative lens groups in turn from an object side. The first positive lens group is provided with the cemented lens of a negative lens and a positive lens on the most object side. Then, following conditional expressions (1), (2) and (3) are satisfied. (1)-1.2<r1/fW<-0.3. (2) -2<fW/fC<-0.5. (3) 8<νN-νP. Provided that (r1) is the radius of curvature of the surface of the cemented lens on the most object side, is the focal distance of the whole system at the short focal distance end, fC is the focal distance of the cemented lens,νN is the Abbe number of the negative lens of the cemented lens andνP is the Abbe number of the positive lens of the cemented lens.
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