Orion 10" f/3.9 Newtonian Astrograph Reflector

  • Sale
  • Regular price $699.99
  • Orion 10" f/3.9 Newtonian Astrograph Reflector

    • Sale
    • Regular price $699.99
    • ITEM #

    • Will not ship until



    • Aperture: 254mm (10")
    • Focal Ratio: f/3.9
    • Focal Length: 1000mm
    • Great value choice for a Newtonian Reflector Telescope

    Orion 10" f/3.9 Newtonian Astrograph Reflector

    Orion's largest reflector optimized for astrophotography boasts 10" parabolic primary optics with a very fast f/3.9 focal ratio for exceptional wide-field, deep-space imaging performance. Even faint galaxies and nebulae exhibit stunning detail with limited exposure time when photographed through this large-aperture astrograph with a CCD imager or DSLR camera. You'll get incredibly bright, crisp images that will make apo refractor aficionados green with envy - and you'll have more green in your wallet thanks to this telescope's more-affordable Newtonian design.

    Both the 10" (254mm) primary and secondary mirror feature enhanced reflectivity (94%) aluminization for bright, contrast-rich images. The 82mm minor axis secondary mirror provides excellent full-field illumination with modern CCD imagers and DSLR cameras, with less than 8% light drop-off at the edge of APS-C sized sensors. The adjustable 4-vane secondary mirror holder features very thin, 1mm thick spider vanes to minimize diffraction effects in images. A center mark on the primary mirror and three easy-grip collimation knobs make optical alignment easy and precise.

    Extended tube length of 7.5" in front of the focuser blocks intrusion of off-axis light, ensuring optimum image contrast. The sturdy 2" dual-speed (11:1), low-profile Crayford focuser permits ultra-fine focus and has 38mm of drawtube travel and a helpful drawtube lock knob. A steel reinforcing plate bolted inside the 38.6" long tube directly under the focuser helps eliminate flexure between it and tube, even with heavy imaging gear attached.

    As with any fast Newtonian, an optional coma corrector is recommended to achieve flat-field imaging performance. Standard accessories include two cast aluminum tube rings, a 9x50 finder scope, 2" and 1.25" extension adapters, and a 12V DC fan for accelerated primary mirror cool-down (fan requires 12V power supply or 8 AA batteries, not included).

    Not only does this affordable astrograph excel as an astrophotography instrument, but the Orion 10" f/3.9 Newtonian can also be used as a formidable visual telescope. Its large 10" aperture and fast focal ratio will provide wondrous views of deep space objects, the planets and Moon, and sparkling star fields in both 2" and 1.25" telescope eyepieces.

    Get the Orion 10" f/3.9 Newtonian Astrograph reflector telescope today and take your shot!

    Orion 10" f/3.9 Newtonian Astrograph Reflector Telescope Specifications...
    • User level: Advanced
    • Optical design: Reflector
    • Optical diameter: 254mm
    • Focal length: 1000mm
    • Focal ratio: f/3.9
    • Optics type: Parabolic
    • Glass material: Low thermal expansion glass
    • Resolving power: 0.46arc*sec
    • Lowest useful magnification: 25x
    • Highest useful magnification: 300x
    • Highest theoretical magnification: 500x
    • Limiting stellar magnitude: 14.7
    • Optical quality: Diffraction limited
    • Finder scope: 9x50
    • Focuser: 2" dual-speed Crayford
    • Secondary mirror obstruction: 82mm
    • Secondary mirror obstruction by diameter: 32%
    • Secondary mirror obstruction by area: 10%
    • Mirror coatings/ over-coatings: Enhanced Aluminum & Silicon Dioxide
    • Mount type: Optical tube without mount
    • Astro-imaging capability: Lunar, planetary & long exposure
    • Tube material: Steel
    • Optical tube length: 38.6"
    • Optical tube weight: 25.5 lb.
    • Additional included accessories: Tube rings, Cooling accelerator fan, 2" to 1.25" adapter
    • Other features: Primary mirror center mark, Extended tube in front of focuser, Quick collimation cap
    • Warranty: One year

    Orion Product Number: 8296

    Additional Information

    Aperture254 mm (10")
    Focal Length1000mm
    Focal Ratiof/3.9
    Highest Useful Magnification300x
    Limiting Stellar Magnitude14.2
    Optical DesignNewtonian Reflector

    Questions & Answers

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    • Which is better, this or the Orion 8" f/3.9 Astrograph Newtonian Reflector?

      I think it depends on what you're planning on imaging. The 10 inch will give you a longer focal length and more light grasp while the 8" will give you a wider field. And, depending on the mount you have, the 8" going to be lighter. Please give me a c

    • Is this good for faint deep sky astrophotography?

      Yes, this will make a great low-cost, large aperture astrograph. For all but the smallest sensors, it would be a good idea to also plan on purchasing a Newtonian Comma Corrector (like the Tele Vue Parracor, Baader MPCC, or TPO Newtonian Comma Corrector) t

    • Is there an adapter for 1.25 " eyepiece?

      This telescope does come with a 1.25" eyepiece adapter.