摘要 |
Optical apparatus for biocular viewing of relatively low cost and light weight comprises a solid Cassegrain configuration in a solid meniscus element having a negative lens element cemented to its convex face and an associated corrector lens element which provide a magnified collimated image of an object for viewing by a pair of telescopes having light folding means to provide an exit pupil separation suitable for two eye viewing. At least some of the lens elements may be of plastics material and aspheric surfaces may be employed. The apparatus is particularly useful for night vision goggles having a single image intensifier tube.
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