| 摘要 |
PROBLEM TO BE SOLVED: To provide a zoom lens in which the size and weight of a first group can be reduced while keeping high optical performance. SOLUTION: The first group G1 comprises, in order from object side, a negative lens group G11, a first positive lens group G12 that moves on the optical axis at the time of focusing, and a second positive lens group G13. The negative lens group G11 is composed of three negative lenses L111 to L113 and one positive lens L114. The first positive lens group G12 is composed of a cemented lens of a positive lens L121 whose image-side face has a relatively large curvature and a negative meniscus lens L122 whose convex face is directed to the image side. The second positive lens group G13 comprises, in order from object side, at least one positive lens L131, a negative meniscus lens L132 whose convex face is directed to the object side, and a plurality of other positive lenses L133 to L136. COPYRIGHT: (C)2005,JPO&NCIPI
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