Icon class icon_class fas fa-quote-left icon_class_computed fas fa-quote-left Related content The Gregorian telescope employs a concave secondary mirror that reflects the image back through a hole in the primary mirror. Source Wikipedia Copyright information Text from Wikipedia and Wiktionary web pages quoted for educational purposes is subject to the Wikipedia Creative Commons Attribution ShareAlike Licence Snippet kind INFO Keywords Gregorian reflector aplanatic Gregorian reflector optical telescope telescope reflecting telescope reflector Giant Magellan Telescope Previous snippet Full quote The overall focal ratio of the complete telescope will be f/8 and the optical prescription is an aplanatic Gregorian telescope. URL https://en.wikipedia.org/wiki/Giant_Magellan_Telescope Next snippet Related snippets Related snippets (backlinks) Visit also Visit also (backlinks) Flags