If you’ve been on the fence about purchasing a Ritchey-Chretien telescope for astrophotography, hop off it now and take a look at the Orion 10″ f/8 Truss Tube Ritchey-Chretien Astrograph. It features premium quartz mirror optics housed in an ingenious truss tube support structure originally developed in 1935 for the 200″ Hale Telescope at the Palomar Observatory! This exquisitely engineered telescope is optimized for astrophotographic excellence – and will take your imaging pursuits to a whole new level! Unlike Newtonian reflector and Schmidt-Cassegrain designs that are susceptible to coma, the Orion 10″ f/8 Truss Tube Ritchey-Chretien Astrograph utilizes hyperbolic primary and secondary mirrors to achieve wonderfully flat images that are virtually coma-free. And since there are no lenses involved, images are free of chromatic aberration. Both mirrors are figured from low-expansion quartz glass and boast 96% reflectivity. The 10″ (250mm) primary mirror is fixed in place to eliminate “image shift” that plagues Schmidt- and Maksutov-Cassegrains. The Serrurier carbon fiber truss system is thermally stable, minimizing focus shift due to temperature changes. Plus, since it’s an open tube, the optics cool down faster than solid tube versions. The focuser on the Orion 10″ f/8 Truss Tube Ritchey-Chretien Astrograph is a 3.3″ dual-speed (10:1) linear bearing Crayford design that provides extra support for up to 9 lbs. of imaging gear without flexure or slippage. Both 2″ and 1.25″ accessory collars permit the use of 2″ or 1.25″ accessories. The Orion 10″ f/8 Truss Tube Ritchey-Chretien Astrograph tube assembly is equipped with a D-style dovetail mounting bar on both the bottom and top. Also included are a dovetail finder scope base, three 1.5″ 12V DC cooling fans on the rear cell, three extension rings, and mirror dust covers. Optical tube weighs 35 lbs. We recommend mounting it on the Orion Atlas Pro AZ/EQ-G or HDX110 EQ-G mounts.
