The GSO 14" f/8 Ritchey-Chrétien Astrograph is a dream telescope for astrophotography. The scope is perfect for small observatories.
The GSO 14" 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.
The telescope is perfect for small observatories and will be carried from mounts in the EQ8 class.
14” 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 focuser can be adjusted (tilted) independently from the primary mirror.
This newest version of the 14RCT makes 14" coma-free true Ritchey-Chrétien imaging available to the DSLR and large format CCD astrophotographer at a price less than that of some large format CCD cameras by themselves.
Featuring first-quality 99% reflectivity dielectric mirror coatings and premium low thermal expansion quartz mirrors, rather than aluminized Pyrex glass mirrors, this reasonably-priced 14” Truss-tube R-C provides the coma-free photographic field that large format CCD and DSLR astrophotographers crave, but can’t get from conventional reflectors and Schmidt-Cassegrains.
Likewise, as a pure two-mirror system, the 14RCT has a wide spectral response and is totally free from the spurious color that affects the imaging of all but the most costly apochromatic refractors, and it does it with a 14” aperture that dwarfs the light gathering of every commercially-available apo refractor.
If serious astrophotography is your goal, but the price of true Ritchey-Chrétien optics has been keeping you from the optical design most modern professional observatories use, your wait is over. The 14” RCT truss-tube R-C can bring the world of professional DSLR/CCD deep space imaging to your backyard observatory at a truly affordable price.
GSO has optimized this 14" RC especially for astrophotography
The OTA comes with carbon trusses having a thermal expansion of nearly 0. The OTA weight is 30 kg and it has a Losmandy style dovetail rail on both sides.
Our 14" f/8 RC Astrograph illuminates a max. field diameter of approx. 70 mm
Without corrector, 35 mm are possible. In the latter configuration, you have a pure mirror system without any lenses. You don´t need an IR cut filter and can use the full spectrum with a suitable CCD camera.
How to find the focus :
The GSO RC has a generous back focus allowing to attach many accessories like off-axis guiders, filter wheels and much more. The distance from the tube backplate to the focus point is 280 mm.
To reach the perfect focus position, we suggest the extension rings. The position of the rings is between focuser and tube backside. So you always have a good position of the draw tube.
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.
The 3" M-LRN Monorail Focuser :
The 3" Monorail focuser is a further development of the Crayford design. The load is not carried by four (often underdimensioned) ball bearings, but on a stainless steel track on the base, thus preventing tilting and bending even under high loads. It is countered by a big knurled screw that centers the inner tube exactly to the rail. The load is distributed evely across the rail´s surface.
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 :
- 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 RC Telescopes are 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 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 30 kg + focuser + camera equipment. We suggest:
- Skywatcher EQ8 / Orion HDX 110
- Celestron CGE Pro
- 10Micron GM 2000
- Losmandy Titan
- TS WS240