The GSO 10" f/8 Ritchey-Chrétien Astrograph is a dream telescope for astrophotography. The telescope is fitted with a stable Carbon Fiber Truss tube and a precise 3" dual speed Monorail focuser.

The GSO 10" f/8 Ritchey-Chrétien Truss Tube Astrograph is a true RC telescope and will give you spectacular photo results also with large format camera sensors. But also visual observing is a highlight with this powerful telescope.

The telescope is transportabel and will be carried from mounts in the EQ6 class.

10” f/8 true Ritchey-Chrétien hyperbolic mirror optical design
carbon fiber truss tube design with CNC-machined stainless steel and aluminum components
low thermal expansion quartz primary and secondary mirrors
99% reflectivity non-tarnishing multi-layer dielectric mirror coatings
three built-in cooling fans in rear cell
focuser attachment collar isolated from the primary mirror and baffle tube
3" MONORAIL Focuser with better stability
dust covers and finder shoe
Big corrected flat field without need for additional correctors

The Carbon Fiber Truss Tube Design:
Lightweight yet strong carbon fiber truss tubes have low thermal expansion characteristics. Shifts in focus due to temperature changes are minimized because of this design. The trusses are also designed to flex equally, keeping the optics in collimation regardless of the position of the telescope.
Technical details of the focuser:

- Travel: ca. 80 mm
- Clear aperture: 68 mm
- Guidance: by massive and fixed steel rail
- 1:10 transmission for precise focusing
- 360° Rotation
- Adaption to 2" and (when screwed off) female M68 thread, directly fitting to TS 2.5" off-axis guider

Optical Highlights :
The hyperbolic primary and hyperbolic secondary are made from low expansion quartz, and finished with a scratch-resistant highly reflective 99% dielectric coating for great contrast. The primary mirror is fixed in place in a metal mirror cell, and the secondary resides in a metal housing that can be collimated. The secondary mirror has a center mark for easy and accurate collimation.
 
Cooling Fans :
The RC telescope has three small cooling fans in the rear cell that help create an ambient temperature within your telescope for more stable viewing and less fluctuation in focus. The fans are powered by an external battery pack. This battery holder accepts 8 AA batteries (sold separately).
 
A Fixed Primary Eliminates Image Shift :
Schmidt-Cassegrain, EHD, ACF... & Mak-Cassegrain telescopes achieve focus by moving the primary mirror back and forth inside the optical tube assembly, and this movement can cause image shift. While manufacturers have done a pretty good job of minimizing image shift on their telescopes, a moveable mirror makes it almost impossible to eliminate it completely. The Ritchey-Chrétien has a primary that is fixed in place, removing the possibility of image shift and also the job of collimating the primary.
 
Why the RC Telescope is better than Schmidt-Cassegrain telescopes with correctors: 
This is also the advantage of RC telescopes against Celestron EHC or Meade ACF telescopes. These telescopes needs a lens corrector wich is integrated in the optical system. The RC is a true reflection system without lens corrector and with a really bright image.
 
The optical advantages of RC Ritchey-Chrétien Astrographs for astrophotography :
The GSO RC Astrograph is a real Ritchey-Chrétien reflector telescope. Contrary to Maksutovs or Schmidt-Cassegrains which have spherical mirrors and need image correctors, and contrary to Newtonians that need coma correctors, the RC system is a well corrected photographical instrument that uses only mirrors (no false colour!) and does not require any corrector with many cameras.
 
Mount Recommendations :
You need a strong mount to carry the weight of 15.2kg + focuser + camera equipment. We suggest:
- Skywatcher EQ6 or AZ-EQ6 Goto / Orion Atlas
- Celestron CGEM or CGEM-DX
- iOptron CEM60
- Losmandy G11