| 摘要 |
There is disclosed a zoom lens system comprising, in order from an object side, a positive first lens unit, a negative second lens unit, a positive third lens unit and a fourth lens unit having a refractive power, during magnification change from a wide-angle end to a telephoto end, a space between the first lens unit and the second lens unit, a space between the second lens unit and the third lens unit and a space between the third lens unit and the fourth lens unit change, the second lens unit has a double-concave negative lens closest to the object side, and includes two or less negative lenses and one positive lens as a whole, the total number of the lenses of the second lens unit is two or three, and the following conditions are satisfied: <?in-line-formulae description="In-line Formulae" end="lead"?>0.0<SF2n1<0.9 (1); and<?in-line-formulae description="In-line Formulae" end="tail"?> <?in-line-formulae description="In-line Formulae" end="lead"?>3.8<ft/fw<10.0 (16).<?in-line-formulae description="In-line Formulae" end="tail"?>
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