| 摘要 |
An internal focusing type telephoto lens which, while maintaining a superior optical performance, has a small effective aperture of the focusing lens as well as a small focusing movement amount. The lens includes first, second and third lens groups designated as G1, G2 and G3, respectively. The internal focusing type telephoto lens performs focusing by moving the second lens group G2 along the optical axis. The first lens group G1 has a positive refractive power, the second lens group G2 has a negative refractive power, and the third lens group G3 has a positive refractive power. The first lens group G1 and the second lens group G2 form a nearly afocal system. The first lens group G1 has, at the object side, a negative meniscus lens L11 having a convex surface that faces towards the object side.
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