Orion 8" f/3.9 Newtonian Astrograph Reflector Telescope

About this product

Our 8" aperture deep-sky imaging specialist boasts features usually reserved for much pricier astrophotography telescopes. In fact, the Orion 8" f/3.9 Newtonian Astrograph's powerful imaging performance easily exceeds what's achievable with many premium apo refractors costing thousands of dollars more.

Its 8" parabolic primary mirror has 800mm of focal length, making the fast f/3.9 Newtonian an ideal wide-field astrophotography telescope. A substantial 70mm minor axis secondary mirror provides full field illumination to CCD and/or DSLR cameras for efficient astrophotography performance. This provides less than 10% light drop-off around the corners of very large APS-C sized sensors. Both primary and secondary mirrors boast enhanced reflectivity (94%) aluminum coatings with a protective silicon dioxide (quartz) overcoat. Three easy-grip, push-pull collimation hand knobs on the primary cell make collimation adjustments easy. Once aligned, three locking thumbscrews secure the 8" parabolic mirror.

Images acquired with the 8" f/3.9 Newtonian Astrograph will exhibit maximum contrast thanks to sophisticated telescope features any astrophotographer will appreciate. Nine precisely positioned baffle rings along the inside of the reflector optical tube minimize internal reflections of pesky off-axis light for pristine imaging performance. To further optimize contrast and avoid off-axis light intrusion near the front of the telescope, the dual-speed 2" Crayford focuser has been installed a full 6.3" back from the front of the 30" long reflector optical tube. What's more, the entire inside of the rigid, rolled steel optical tube is coated with high-quality flat black paint to ensure high contrast.

The reflector telescope's low-profile Crayford-style focuser has a full 69mm of backfocus, making it ideal for use with multiple imaging accessories. The smooth-adjusting focuser is held rigidly in place without any possibility of flexure thanks to a sturdy internal steel reinforcing plate. With fine focus adjustment capabilities at a ratio of 11:1, the smooth focuser is a joy to use and makes it easy to perform minute focus adjustments. Drawtube tension is adjustable, so you can customize focuser tension according to the load of astrophotography accessories being used.

As with any fast Newtonian reflector telescope, an optional coma corrector is recommended to eliminate inherent coma for optimized imaging performance. When used with a coma-corrector, the 8" Newtonian Astrograph will astound you with the amount of depth and resolution seen in astrophotos with round stars all the way out to the edges of the substantial field of view.

The 8" Newtonian Astrograph can also be used for spectacular visual observations of deep-sky and solar system based celestial objects. The reflector's 8" aperture and fast focal ratio will amaze you with high-contrast views of the cosmos. Handy extension adapters are included for optimal use of 2" and 1.25" telescope eyepieces.

A thorough complement of accessories comes with the 8" f/3.9 Newtonian Astrograph telescope. Standard accessories include a cooling accelerator fan for speedy temperature equilibration, a pair of cast aluminum tube rings equipped with both upper and lower 1/4"-20 mounting holes, quick collimation cap, and a 9x50 finder scope. Eight AA batteries (not included) are required for cooling accelerator fan operation, or a portable 12V power supply (sold separately) can be used.

With a weight of just 17.5 lbs. by itself, and 21.8 lbs. with the included accessories installed, the Orion 8" f/3.9 Newtonian Astrograph can be supported easily by most equatorial mounts designed for astrophotography use.

• Best for viewing

  Brighter deep sky
• Best for imaging

  Deep sky
• User level

  Intermediate
• Optical design

  Reflector
• Optical diameter

  203mm
• Focal length

  800mm
• Focal ratio

  f/3.9
• Optics type

  Parabolic
• Glass material

  Low thermal expansion glass
• Resolving power

  0.57arc*sec
• Lowest useful magnification

  29x
• Highest useful magnification

  300x
• Highest theoretical magnification

  400x
• Limiting stellar magnitude

  14.2
• Optical quality

  Diffraction limited
• Finder scope

  9x50
• Focuser

  2" dual-speed Crayford
• Secondary mirror obstruction

  70mm
• Secondary mirror obstruction by diameter

  35%
• Secondary mirror obstruction by area

  12%
• Mirror coatings/over-coatings

  Enhanced Aluminum & Silicon Dioxide
• Mount type

  Optical Tube without Mount
• Astro-imaging capability

  Lunar, planetary & long exposure
• Tube material

  Steel
• Length of optical tube

  30.0 in.
• Weight, optical tube

  17.5 lbs.
• Additional included accessories

  Pair of tube rings, Cooling fan, 2" & 1.25" extension adapters, Collimation cap, User guide, Starry Night SE software
• Other features

  Nine internal baffle rings ensure maximum contrast, Extended-length optical tube in front of focuser, Steel plate eliminates flexure under focuser