| 摘要 |
PROBLEM TO BE SOLVED: To provide a high power zoom lens having a high zooming ratio irrespective of its small size and capable of preventing fluctuation of spherical aberration and coma aberration during zooming and achieving satisfactory optical performance. SOLUTION: This high power zoom lens includes, in order from the object side: a first lense group G1 having a positive refractive power and remaining stationary during zooming; a second lense group G2 having a negative refractive power and moving during zooming; a third lense group G3 and a fourth lense group G4 having a positive refractive power and being movable relative to each other to correct image plane variation accompanying zooming; and a fifth lense group G5 having a positive refractive power for forming an image and including an aperture diaphragm. The second lens group G2 and a composite lens group formed by combining the third lens group G3 and the fourth lens group G4 pass simultaneously through -1x magnification points of the groups during zooming from a wide-angle end to a telephoto end. The fourth lense group G4 has at least one aspheric surface. COPYRIGHT: (C)2009,JPO&INPIT
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