| 摘要 |
The present invention relates to photographic lens systems and more particularly, to a large-aperture wide-angle retrofocus lens system with a field angle about 76 DEG and aperture ratio F:2. The lens system of the present invention comprises a front and rear lens groups; said front lens group being arranged by three lenses, i.e., a positive meniscus lens and two negative meniscus lenses, in order to as far as possible minimize the positive spherical aberration caused by the front lens group and said rear lens group including a cemented lens with a cemented surface having a strong positive power to correct the above-mentioned positive spherical aberration.
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