发明名称 |
Optical attachment for reducing the focal length of an objective lens |
摘要 |
An optical attachment configured to be operably attached to the image side of an objective lens to reduce the focal length and focal ratio of the objective lens. The focal-reducing attachment includes four lens elements and has a magnification of between 0.5 and 1. The focal-reducing lens can work with objective lenses having relatively large working distances for a large format size as well as with cameras having a smaller format size and relatively small permissible working distance.
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申请公布号 |
US2013064532(A1) |
申请公布日期 |
2013.03.14 |
申请号 |
US201213589880 |
申请日期 |
2012.08.20 |
申请人 |
CALDWELL J. BRIAN;BITTNER WILFRIED |
发明人 |
CALDWELL J. BRIAN;BITTNER WILFRIED |
分类号 |
G02B9/34;G03B19/02 |
主分类号 |
G02B9/34 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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