| 摘要 |
There is provided a zoom lens including broad picture angle of 60 to 100 degrees as photographic picture angle of the wide-angle end state, and having magnification ratio of about three to six times, small front gem diameter, excellent compactness and high image formation performance, which is used in video camera or digital still camera, and an image pick-up apparatus using such a zoom lens. A zoom lens ( 20 ), consisting of plural groups and serving to change group spacing or spacings to thereby perform magnification changing or adjusting operation, comprises a first lens group GR 1 having positive refractive power, a second lens group GR 2 having negative refractive power and a third lens group GR 3 having positive refractive power which are arranged in order from the object side, and a last group GRR arranged at the side closest to the image surface and having negative refractive power, wherein the first lens group GR 1 is constituted by single positive lens G 1 , and satisfies the following conditional formulas. <?in-line-formulae description="In-line Formulae" end="lead"?>0.5<Ymax/FW<1.3 (1)<?in-line-formulae description="In-line Formulae" end="tail"?> <?in-line-formulae description="In-line Formulae" end="lead"?>VdG1>40 (2)<?in-line-formulae description="In-line Formulae" end="tail"?> In the above formula, Ymax: maximum image height on image pick-up surface FW: focal length at the wide-angle end state of the lens entire system VdG 1 : Abbe number at d line of the first lens group GR 1.
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