| 摘要 |
A zoom lens having, in order from an object side to an image side, a first lens unit of negative refractive power, a second lens unit of positive refractive power and a third lens unit of negative refractive power, the first lens unit and the second lens unit being axially moved to effect zooming, wherein the first lens unit comprises, in order from the object side to the image side, a positive first lens, a negative second lens of meniscus form having a strong concave surface facing the image side, a negative third lens of bi-concave form and a positive fourth lens of meniscus form having a convex surface facing the object side, and the third lens unit comprises, in order from the object side to the image side, a negative first lens of bi-concave form and a positive second lens, and wherein the zoom lens satisfies the following conditions: 0.8< beta 2Wx beta 2T<1.2 0.45<|f1|/fT<0.59 0.37<f2/fT<0.43 where beta 2W is an image magnification of the second lens unit in a wide-angle end, beta 2T is an image magnification of the second lens unit in a telephoto end, fT is a focal length of the zoom lens in the telephoto end, f1 is a focal length of the first lens unit, and f2 is a focal length of the second lens unit.
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