| 摘要 |
PROBLEM TO BE SOLVED: To provide a super wide zoom lens which allows an image angle of wide angle end to become super wide angle of≥80°and permits both of super wide angle and smaller size by suppressing the increase of a front lens size to the utmost. SOLUTION: The imaging apparatus is constituted such that a positive first lens group G1, a negative second lens group G2, a positive third lens group G3, a negative fourth lens group G4 and a positive fifth lens group G5 are arranged in order from the object side, the first lens group, the third lens group and the fifth lens group are fixed, variable magnification is performed mainly by moving the second lens group, and the correction of fluctuation of image position and the focusing are performed by moving the fourth lens group. The first lens group is constituted by arranging a concave lens group consisting of one sheet or more lenses, a convex lens which faces a strong convex surface to the image side, a cemented lens which comprises a concave lens and a convex lens of Abbe number vd≥84 and a convex lens which faces a strong convex surface to the object side in order from the object side. Therein, at least one surface of the surface of the cemented lens which is brought into contact with air and the convex lens located on the side nearest to the image are aspheric surfaces. COPYRIGHT: (C)2006,JPO&NCIPI
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