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GSO 8" f/8 Ritchey-Chretien Optical Tube - Steel OTA - 8RCS

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$899.00 $764.15
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The Ritchey-Chretien was designed for photographic use, and while you can put an eyepiece in the diagonal and use it visually, you will get less than "stellar" results. It is for this reason that we do not recommend an RC telescope for visual use. If you have any questions or need help choosing a telescope that performs well when used either visually or photographically, please don't hesitate to contact us. Thanks!

GSO 8” f/8 Ritchey-Chretien OTA - Steel

As amateur astronomers advance in their astro-imaging skills, they dream of owning a Ritchey-Chretien telescope. RC telescopes are being used in some of the world’s biggest and best observatories due to their color-free, coma-free, spherical aberration-free optics. The problem is, Ritchey-Chretien telescopes are out of the reach of most people due to their high price tag…until now!

Guan Sheng Optical of Taiwan has been creating affordable imaging telescopes for several years. After the huge success of their Imaging Newtonians, they turned their attention to creating a high-quality Ritchey-Chretien at a more reasonable price. Now serious astro-imagers can choose from closed tube or open tube RC telescopes in a wide range of apertures!

This GSO Ritchey-Chretien has 8” of aperture and a focal ratio of f/8. The primary & secondary mirrors are made from quartz, famous for its low thermal expansion. The optical set is multi-coated with 99% dielectric coatings. This high reflectivity coating offers higher contrast images and protection against scratching.

The optical tube assembly of the GSO 8” RC Telescope is made of steel and painted white. Inside the 8” RC OTA is a Knife-Edge Baffle System whose only job is to keep stray light out of the telescope’s interior. Stray light eats contrast for breakfast (or a late night snack) and is, therefore, our enemy. The addition of a dew shield (sold separately) will help further defeat stray light, we recommend picking one up. The OTA mounts easily to a variety of mounts with the included dovetail plate. Simply remove the dovetail if you choose to mount the telescope via cradle rings.

One thing that really sets this telescope apart from Schmidt-Cassegrains, even though it looks like one, is the lack of image shift. In SCT’s, the focuser moves the mirror forward and back on a rail, and it is this movement that can cause image shift. The mirror of the GSO 8” RC is fixed into place, similar to that of a Newtonian…it is not connected to the focuser in any way. Removing this connection removes image shift…voila! To collimate the RC, adjustments are made to the secondary mirror.

The GSO 8" RC comes with a 2" dual-speed linear-bearing Crayford focuser. This focuser is very sturdy and has a monorail that will keep drag under heavy loads to a minimum. You can achieve rough focus with the larger of the two knobs, and then tweak your focus with the smaller 10:1 micro-focusing knob. There are two other knobs on the focuser: A tension knob allows you to adjust the drag on the draw tube to match the weight of the load, and the second knob locks the focus in place; a real help when imaging. A 2" to 1.25" compression ring adapter is included as standard equipment.

GSO 8” f/8 RC Telescope OTA Specifications

  • Optical Design: Ritchey-Chretien
  • Aperture: 8”
  • Focal Length: 1625 mm
  • Focal Ratio: f/8
  • Mirror Material: Low Expansion Quartz
  • Coatings: 99% Dielectric - Multi-Coated
  • OTA Weight: 18.5 lbs.
  • Optical Tube Material: Steel, painted white