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Orion Telescopes
Orion 10" f/8 Ritchey-Chretien Astrograph Telescope
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3 easy payments of $833.33
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Expected Ship Date: 10/12/2024

  • 10" (250mm) aperture, f/8 Ritchey-Chretien optical tube optimized for astrophotographic use with APS-C and full-frame (35mm) CCD cameras and DSLRs
  • Features a big 3.3" 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" cooling fans accelerate cooling of the primary mirror to reach thermal equilibrium quickly

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Item #  08266b

Go after even the most elusive and faint deep-sky targets with the Orion 10" f/8.0 Ritchey-Chrétien Astrograph. Featuring the highly regarded Ritchey-Chrétien optical design with excellent light gathering, a host of deluxe features, durable construction, and virtually coma-free optics, the big 10" RC is the ideal choice for astrophotographers searching for a superb imaging instrument.

Unlike conventional Newtonian reflector and Schmidt Cassegrain (SCT) designs that are susceptible to displaying coma away from the center of the field, the acclaimed Ritchey-Chrétien design utilizes hyperbolic primary and secondary mirrors to achieve wonderfully flat images that are virtually coma-free with pinpoint star clarity all the way out to the field edge. Plus, since there are no lenses in an "RC" telescope, captured images are delightfully free of chromatic aberrations for true-color performance. Both the primary and secondary mirrors of the Orion 10" RC are made of low-expansion quartz glass and feature enhanced aluminum coatings to provide 96% reflectivity with a protective quartz overcoat. The primary mirror of the Orion 10" Ritchey-Chrétien is fixed in-place to eliminate annoying "image shift" that plague Schmidt-Cassegrain telescopes which can wreak havoc during imaging sessions. The secondary mirror is precisely center-marked to facilitate collimation. The 10" enameled steel optical tube is fortified with 8 internal, computer-positioned, knife-edge light baffles; and both the primary mirror tube and secondary mirror light shield are also highly baffled to ensure maximum image contrast. All these elements come together to make this 10" Ritchey-Chrétien Astrograph an ideal instrument for capturing bright and detailed images of deep-space objects with APS-C and full-frame (35mm) CCD cameras and DSLRs.

The Orion 10" Ritchey-Chrétien Astrograph features a huge, 3.3" dual-speed (10:1) modified Crayford focuser with a sturdy linear track bearing that provides rigid, backlash-free support of hefty imaging cameras and accessories. An engraved millimeter scale on the focuser drawtube allows easy focus point repeatability. One 2" and two 1" machined focus extension rings are included so you can adjust focus position for various imaging cameras and accessories. The 10" Ritchey-Chrétien Astrograph has a backfocus distance of 139.6mm, measured from the 2" collar, and 243.9mm when measured from the rear cell.

Two dovetail finder scope bases positioned on either side of the telescope focuser allows easy installation of optional finder scopes and aiming devices (sold separately). Three built-in 1.5" DC cooling fans on the rear cell helps accelerate mirror cooldown to save time during imaging sessions. A wide, "Losmandy-style" dovetail bar along the bottom of the telescope makes it easy to couple the 35.3 lb. Ritchey-Chrétien optical tube to heavy-duty equatorial mounts. A unique, Orion-exclusive, slotted wide dovetail bar along the top of the 10" RC facilitates easy attachment of optional guide scopes and other imaging accessories.


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. For complete warranty details contact us at 800-447-1001.


Please note this product was not designed or intended by the manufacturer for use by a child 12 years of age or younger.

Product Support
Visit our product support section for instruction manuals and more
  • Best for viewing
    Brighter deep sky
  • Best for imaging
    Deep sky
  • User level
  • Optical design
  • Optical diameter
  • Focal length
  • Focal ratio
  • Optics type
  • Eyepieces
  • Resolving power
  • Lowest useful magnification
  • Highest useful magnification
  • Highest theoretical magnification
  • Limiting stellar magnitude
  • Optical quality
    Diffraction limited
  • Finder scope
  • Focuser
    3" dual-speed linear bearing Crayford
  • Secondary mirror obstruction
  • Secondary mirror obstruction by diameter
  • Secondary mirror obstruction by area
  • Mount type
    Optical Tube without Mount
  • Astro-imaging capability
    Lunar, planetary & long exposure
  • Tube material
  • Length of optical tube
    28.4 in.
  • Weight, optical tube
    35.3 lbs.
  • Additional included accessories
    Three built-in cooling fans, with battery holder, 1.25" compression ring adapter, 1" & 2" Extension tubes
  • Other features
    Losmandy-style dovetail mounting bar on underside, Custom Losmandy-style guidescope mounting bar, Two dovetail finderscope bases
  • Warranty
    One year

Orion 10" f/8 Ritchey-Chrétien Astrograph Telescope with 3.3" dual-speed linear-bearing Crayford focuser
Extension tube, 2" length (x1)
Extension tube, 1" length (x2)
Battery holder for eight AA batteries (batteries not included)
Starry Night SE astronomy software digital download insert

Orders received by 1pm Eastern Standard Time for in-stock items ship the same business day. Order received after noon will ship the next business day. When an item is not in-stock we will ship it as soon as it becomes available. Typically in-stock items will ship first and backordered items will follow as soon as they are available. You have the option in check out to request that your order ship complete, if you'd prefer.

A per-item shipping charge (in addition to the standard shipping and handling charge) applies to this product due to its size and weight. This charge varies based on the shipping method.

Standard Delivery: $0.00
Standard Delivery to Canada: $60.00
3 Day Delivery: $101.00
2 Day Delivery: $101.00
Next Day Delivery: $118.00

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