| 摘要 |
PROBLEM TO BE SOLVED: To shorten the entire length of a lens, to make the angle of view comparatively wide and to obtain high optical performance over an entire variable power range where a variable power ratio is high by constituting the lens so that it may have four lens groups being a 1st group to a 4th group, power may be varied by changing an air distance between the respective lens groups and the 2nd group may satisfy a specified condition. SOLUTION: As for this zoom lens, power is varied by changing an air distance between respective lens group L1 to L4, the 2nd group L2 has a stuck lens obtained by bonding a 21st lens being a negative meniscus lens whose convex surface faces to an object side and a 22nd lens being a positive lens whose both surfaces are convex and a 23rd lens being a positive lens whose strong positive refractive surface faces to the object side. Then, when it is assumed that the radius of curvature of the bonded surface of the stuck lens where the surface of the 21st lens or the 23rd lens on the object side is made aspherical is R2, 2, the aspherical coefficient of the aspherical surface is B and C, the outside diameter of the 23rd lens is DE and the focal distance of the 2nd group is F2, the 2nd group satisfies the condition being expressions; 0.6<R2, 2/F2<1.0, B<0 and B+C×(DE/2)2<0.
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