| 摘要 |
PROBLEM TO BE SOLVED: To make the telephoto/wide-angle power variation ratio large even in a shutter-diameter reduced state while making the lens compact and low-cost by making the focal lengths of lenses on a wide-angle side and a telephoto side meet specific conditions. SOLUTION: The wide-angle side lens(WIDE) and telephoto side lens(TELE) are selectively set at a photographic lens position through lens switching operation. The wide-angle side lens is composed of two positive meniscus lenses L1 and L2 which are concave to a subject side and an aperture stop 2 is arranged between the lens L2 and a fixed shutter 1 positioned on its imaging plane side. The telephoto side lens is composed of only a positive meniscus lens L1' which is convex to the subject side and an aperture stop 2' is arranged between the lens L1' and the fixed shutter 1 positioned on its imaging plane side. A conditional inequality 1.2<fT/fW<2.1 holds, where f2 is the focal length of the wide-angle side lens and fT is the focal length of the telephoto side lens.
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