Orion 6" f/9 Ritchey-Chrétien Imaging Optical Tube Assembly

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  • Regular price $499.99

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  • 6" (152mm) aperture, f/9 Ritchey-Chretien optical tube ideal for use with DSLR cameras and small-format CCD imagers to produce wonderfully flat, virtually coma-free images
  • Hyperbolic primary and secondary mirrors with enhanced aluminum coatings boast 96% reflectivity for bright imaging performance
  • Conveniently compact and portable astrograph ideal for on-the-go astrophotographers
  • Rotatable, 2" dual-speed (10:1) machined Crayford focuser provides precise focus adjustment control
  • Features two dovetail finder scope bases and includes one 2" and two 1" focus extension rings so you can adjust focus position for various imaging cameras and accessories

The conveniently portable and compact Orion 6" Ritchey-Chrétien Astrograph telescope brings advanced imaging performance into the realm of affordability for amateur astrophotographers. This 6"-aperture optical tube combines the highly regarded Ritchey-Chrétien optical design with excellent portability, great light gathering capability, high-end features and durable construction to provide celestial shutterbugs with an exceptional instrument at an amazing value.

Unlike conventional Newtonian reflector and Schmidt Cassegrain (SCT) designs that are susceptible to displaying coma away from the center of the field, the compact Ritchey-Chrétien design utilizes hyperbolic primary and secondary mirrors to achieve wonderfully flat images that are virtually coma-free with pinpoint star clarity. Plus, since there are no lenses in an "RC" telescope, captured images are delightfully free of chromatic aberrations for true-color performance. The enameled steel 6" optical tube is fortified with seven computer-positioned internal light baffles, and both the primary mirror tube and secondary mirror light shield are also highly baffled to ensure maximum image contrast. Unlike Schmidt-Cassegrains, the primary mirror of these Ritchey-Chrétien telescopes is fixed in-place to eliminate annoying "image shift" that can wreak havoc during imaging sessions. All these elements come together to make Orion Ritchey-Chrétien Astrographs ideal tools for capturing detailed images of deep-space objects with small-format CCD cameras and DSLR cameras with APS-C sized sensors.

Enhanced aluminum coatings on both the primary and secondary mirrors of the 6" Ritchey-Chrétien Astrograph provide exceptional 96% reflectivity with a protective quartz overcoat. The secondary mirror of the 6" RC is precisely center-marked to facilitate collimation. A machined, rotatable dual-speed (10:1) Crayford focuser with an engraved millimeter scale on the drawtube provides 151.3mm of backfocus distance to easily accommodate imaging gear as well as provide precise focus control. One 2" and two 1" focus extension rings are included so you can adjust focus position for various imaging cameras and accessories. The Orion 6" Ritchey-Chrétien Astrograph features two dovetail finder scope bases positioned on either side of the focuser for easy installation of optional Mini Guide Scopes and aiming devices (finder scopes and Mini Guide Scopes sold separately).

The 6" RC optical tube features a narrow "Vixen-style" dovetail mounting bar for trouble-free setup on medium equatorial mounts. The lightweight 6" RC tips the scales at just 12.1 lbs., so this high-quality astrograph doesn't require an enormous mount to keep it steady. You can achieve wonderful imaging results with the 6" RC attached to a medium equatorial mount such as the Orion Sirius EQ-G (sold separately).


Limited Warranty against defects in materials or workmanship for one year from date of purchase. This warranty is for the benefit of the original retail purchaser only.

  • Orion 6" f/9 Ritchey-Chrétien Astrograph Telescope with 2" dual-speed Crayford focuser
  • Extension tube, 2" length (x1)
  • Extension tube, 1" length (x2)
  • Starry Night SE astronomy software digital download insert
SKU: ORN-08268