| 摘要 |
At least one exemplary embodiment is directed to a zoom lens which includes, in order from an object side to an image side, a first lens unit with a negative refractive power, a second lens unit with a positive refractive power, and a third lens unit with a negative refractive power. The second and third lens units move during zooming. The first lens unit includes a negative biconcave lens element. The zoom lens satisfies the following conditions: <?in-line-formulae description="In-line Formulae" end="lead"?>-1.4<phi1/phiw<-1.0<?in-line-formulae description="In-line Formulae" end="tail"?> <?in-line-formulae description="In-line Formulae" end="lead"?>0.9<phi2/phiw<1.4<?in-line-formulae description="In-line Formulae" end="tail"?> <?in-line-formulae description="In-line Formulae" end="lead"?>-1.3<phi3/phiw<-0.9<?in-line-formulae description="In-line Formulae" end="tail"?> where phi1 is a refractive power of the first lens unit, phi2 is a refractive power of the second lens unit, phi3 is a refractive power of the third lens unit, and phiw is a refractive power of the entire system at a wide-angle end.
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