| 摘要 |
PROBLEM TO BE SOLVED: To provide a zoom lens which possesses two lens groups as a whole, whose entire length is short, whose variable power ratio is about 2 and whose Fno is about 2.8. SOLUTION: This zoom lens is equipped with a 1st lens group having negative refractive power and a 2nd lens group having positive refractive power. The 1st lens group is constituted of four lenses being convex, concave, concave and convex lenses in order from a subject side and the 2nd lens group is constituted of five lenses being convex, concave, concave, convex and concave lenses from the subject side. The lens (9th lens) nearest to an image surface side in the 2nd lens group has one aspherical surface and satisfies following conditional expressions. (1) 2.2<=|f|/d<=2.6, (2) 1.5<=g/d<=1.7, (3) 1.8<=e/d<=2.2, (4) 0.9<=o/d<=1.1, (5) 1.1<=p/d<=1.3.
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