| 摘要 |
PROBLEM TO BE SOLVED: To provide a highly variable zoom lens which is compact and highly variable and also has an excellent optical performance, and to provide an optical apparatus having the highly variable zoom lens. SOLUTION: The highly variable zoom lens 2 is composed of: a first lens group G1 having positive refractive power; a second lens group G2 having negative refractive power; a third lens group G3 having positive refractive power; and a fourth lens group G4 having positive refractive power in this order from the object side. The third lens group has: a first positive lens the object side face of which is convex; a second positive lens the object side face of which is convex; and a negative lens both sides of which are concave such that the curvature radius of the image side lens face is smaller than that of the object side lens face; and a third positive lens both sides of which are convex in this order from the object side. Either one of the lens faces composing the third lens group is aspherical. When zooming takes place from the wide angle end to the telephoto end, all the lens groups are moved along an optical axis. The highly variable zoom lens 2 satisfies predetermined conditions. The optical apparatus 1 has the highly variable zoom lens 2. COPYRIGHT: (C)2008,JPO&INPIT
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