KPNO 2.1-m (84-inch) line drawing

A cross-section of the Kitt Peak National Observatory's 2.1-meter telescope building shows both the standard telescope operation in Ritchey-Cretien mode, as well as the Coude optical system which feeds the large stable spectrograph attached to the building. This system has been removed, as there is now a separate Coude Feed telescope used with this spectrograph (see this exterior photograph).