| 摘要 |
A description is given of a photographic objective of the modified double gauss type having a front group, comprising of three lens elements (L 1 , L 2 , L 3 ) and having the refractive power sequence ++-, an aperture and a rear group including lens elements (L 4 , L 5 , L 6 ) of refractive power sequence -++, which is distinguished in that in the rear group the lens element of negative refractive power (L 4 ) is designed as a meniscus with an aspheric surface concave relative to the aperture, and a lens element of negative refractive power (L 7 ) with surfaces concave on both sides is arranged downstream of the last lens element of positive refractive power (L 6 ).
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