| 摘要 |
A zoom lens includes, in order from an object side to an image side, a first lens unit having a positive refractive power, a second lens unit having a negative refractive power and configured to move during zooming, a third lens unit having a positive refractive power and configured to move during zooming, and a fourth lens unit having a positive refractive power and configured not to move for zooming. In the zoom lens, the second lens unit includes at least one positive lens and at least one negative lens. Furthermore, in the zoom lens, average values of Abbe number (&ngr;) and relative partial dispersion (&thetas;) of materials of the at least one negative lens (&ngr;na, &thetas;na) and average values of Abbe number (&ngr;) and relative partial dispersion (&thetas;) of materials of the at least one positive lens (&ngr;pa, &thetas;pa) satisfy an appropriate condition.
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