Cassegrain Nasmyth
Jump to navigation
Jump to search
![](http://upload.wikimedia.org/wikipedia/commons/thumb/3/38/Telescope_built_for_visual_work.jpg/220px-Telescope_built_for_visual_work.jpg)
The Cassegrain Nasmyth telescope has the same optical design as the classical Cassegrain telescope except for a small tertiary mirror which sends out the light on the side of the telescope tube instead of through a hole in the primary mirror. This design is common in large telescopes, e.g., the W. M. Keck Observatory.
Figure 1 shows the light-path from a star based on the 0.61m telescope in Oslo. Figures 2 and 3 show the use of a focal reducer, flip mirror unit, ocular and CCD Camera. See also: Nasmyth telescope.