Editing Reflecting telescope (section)

====Nasmyth====

{{Main|Nasmyth telescope}}

The Nasmyth design is similar to the Cassegrain except the light is not directed through a hole in the primary mirror; instead, a third mirror reflects the light to the side of the telescope to allow for the mounting of heavy instruments. This is a very common design in large research telescopes.<ref>{{cite book|author=Geoff Andersen|title=The Telescope: Its History, Technology, and Future|url=https://archive.org/details/telescopeitshist00ande|url-access=registration|year=2007|publisher=Princeton University Press|isbn=978-0-691-12979-2|page=[https://archive.org/details/telescopeitshist00ande/page/103 103]}}</ref>