Orion 10" f/8 Ritchey Chretien Reflecting OTA Telescope

10-Inch (250 mm) aperture, f/8 Ritchey Chretien optical tube optimized for astrophotographic use with APS-C and full-frame (35 mm) CCD cameras and DSLRs Features a big 3.3-Inch rotatable dual-speed (10:1) Crayford focuser equipped with a sturdy linear-bearing to provide fine focus adjustment without slippage or flexure with heavy imaging accessories attached Hyperbolic primary and secondary mirrors made of low-expansion quartz glass with enhanced aluminum coatings boast 96% reflectivity for bright imaging performance, and the secondary mirror is precisely center-marked to aid in collimation Features two dovetail finder scope bases and a unique, Orion-exclusive slotted wide-format dovetail bar along the top of the telescope for easy attachment of imaging accessories Three built-in 1.5-Inch cooling fans accelerate cooling of the primary mirror to reach thermal equilibrium quickly Orion 10" f/8 Ritchey-Chrétien Astrograph Telescope with 3.3" dual-speed linear-bearing Crayford focuser