TS GSO 8" f/8 RC Ritchey-Chrétien Telescope with Carbon Tube.

Most large professional telescope are designed and constructed to the Ritchey-Chrétien principle. Until recently, these telescopes were unaffordable for amateurs. Due to their unique design, Ritchey-Chrétien telescopes are primarily aimed to amateur astronomers with an interest in high resolution Astrophotography however an RC can also still be used for visual observing with an eyepiece if needed.

The advantages of the TS RC Telescopes:

• Hyperbolic primary and secondary mirror for a large fully illuminated field of view.
  
• Astrophotography with camera sensors up to 30mm diameter is possible without corrector. For larger sensors, like full-frame size, a specialised corrector is available.
  
• 94% enhanced reflectivity on the main and secondary mirror for an even brighter image.
  
• Significantly shorter cooling down time due to open construction
  
• Internal baffles in the tube for even more contrast.
  
• High back focus for correctors, reducers and also binoviewers.
  
• Due to a redesign of the baffle tube, problems with stray light no longer occurs. Nevertheless, the illumination is still very good. Sensors up to full frame format can be used.

Astrophotography with the TS  8" RC telescope:
Better and sharper astrophotos without a corrector and with shorter exposure times is exactly what this Ritchey-Chrétien telescope allows you to do with astro cameras and SLRs up to APS-C sensors. As a pure mirror system, you can even use the infrared light. You can achieve up to 25% shorter exposure times and sharper imaging than, for example, through a comparable Schmidt-Cassegrain telescope. For the use of a reflex camera without focal length reduction you need the 50mm and the 25mm extension between focuser and telescope.

The generous backfocus also allows the connection of correctors (which we recommend for the use of full-frame sensors). You can also connect a focal length reducer, thus further increasing the light intensity of the Ritchey-Chrétien.

Accessories - 0.67x CCD reducer for Astrophotography:
The CCD47 reducer improves the focal ratio from f/8 to f/5.36, thus reducing the exposure time to less than 50%. With this, you can capture dim nebulae and galaxies with more moderate exposure times.

The advantages of a carbon tube over a metal tube:
The weight reduction is minimal - only about 300 grams - the main advantage is the focus stability when temperature changes which is important for Astrophotography. When temperatures drop, metal contracts and the focus moves meaning refocusing is necessary. A carbon tube does not change, the combination of quartz glass mirror and carbon composite tube makes a readjustment of the sharpness obsolete, even for long time exposures.

The 2" Monorail focuser:
The Monorail focuser combines the ease of movement of a Crayford focuser with the stiffness of a rack-and-pinion focuser.

Focuser Features:

•  A stainless steel bar instead of small ball bearings for more stiffness.
  
•  No tilting anymore when locking the drawtube.
  
•  360° rotation for optimal object alignment
  
•  Female M69 x 1 thread for threaded adaptions
  
•  2" and 1.25" compression rings for push adaptions
  
•  1:10 dual speed for accurate focusing
  
•  Motor focus can easily retrofitted
  
•  Lined scale for quick retrieving of the focus.
  
•  Easy operation

Telescope Spec:

• Optical Design: True Ritchey-Chrétien design with a hyperbolic primary and secondary mirror
  
• Aperture: 203mm / 8"
  
• Focal length: 1624mm (1088mm using the CCD47 Reducer)
  
• Focal ratio: f/8 (f/5.36 with the CCD47 Reducer)
  
• Resolution: 0.58"
  
• Reflectivity: 94% enhanced reflectivity
  
• Back focus: 254mm from the tube´s backside or 159mm from the 2" receptacle of the focuser
  
• Tube Diameter: 230mm
  
• Tube Length: 580mm with focuser
  
• Weight: 7.6kg with focuser and dovetails
  
• Tube Material: Carbon composite with internal baffles
  
• Total Obstruction by Secondary: 85mm
  
• Focuser: 2" dual speed Monorail
  
• Connection Thread: M90 x 1
  
• Dovetail Bars: 1x GP, 1x Losmandy style, each 395mm long

Whats included:

1.  8" f/8 RC Astrograph
   
2.  2" dual speed Monorail focuser 
3. 2 x Dovetail
   
4.  M90 extension tubes for easy reaching of the focus
   
5. Collimation manual