radiometry
Mechanical
- Dec 30, 2013
- 2
Hi,
My simple telescope consists of a convex lens which images an area with diameter D into the detector diameter d. The object distance is S' and the image distance is s as indicated in the upper graph. Since S'/s=D/d, if I want a smaller field of view (a smaller D), I end with up a larger s and hence a lens with a larger focal length (lower graph). What's the easiest solution to reduce my telescope tube length while keeping the same field of view, a concave lens behind the convex lens? Many thanks.
My simple telescope consists of a convex lens which images an area with diameter D into the detector diameter d. The object distance is S' and the image distance is s as indicated in the upper graph. Since S'/s=D/d, if I want a smaller field of view (a smaller D), I end with up a larger s and hence a lens with a larger focal length (lower graph). What's the easiest solution to reduce my telescope tube length while keeping the same field of view, a concave lens behind the convex lens? Many thanks.