TS-Optics GSO 8″ RC Pro 203/1624 - The benchmark Ritchey-Chrétien astrograph
Visit Ritchey-Chrétien TS-Optics GSO 8″ RC (203 mm, 1624 mm, f/8) is designed for high-resolution astrophotography, but is also perfectly suited to visual observation. With its hyperbolic quartz mirrors (fused silica) with 94 % reflectivity and its ventilated open tube, it guarantees stable focus, bright images and fine stars across the entire field.
Highlights
- Genuine Ritchey-Chrétien naturally corrected, coma-free field.
- Quartz mirrors focus stability even at varying temperatures.
- Reflectivity 94 % direct gain in brightness and contrast.
- Open tube + ventilation rapid cooling, better contrast.
- Generous backfocus (≈159 mm) ideal for correctors, gearboxes, OAGs and filter wheels.
- No shifting : primary fixed, developed by focuser Monorail 2″.
- Two Vixen bars simple mounting of guidescope or piggyback camera.
Astrophotography
The 8″ RC delivers sharper, brighter astrophotos than comparable SCT or Maksutov sensors. Without correctors, sensors up to APS-C are perfectly usable. For full format, an RC corrector is recommended. With the CCD47 reducer 0.67×the focal length increases from 1624 mm to ≈1088 mm and the f/8 ratio to f/5,36which means twice as fast installation times.
The Monorail 2″ focuser
More rigid than a classic Crayford, the Monorail 2″ combines fluidity and stability: solid stainless steel slide, no tilt when locked, 360° rotation for framing, 1:10 gear ratio for precise focusing, graduation for easy focus retrieval, motorization compatibility.
Why RC rather than SCT?
- No Schmidt blade less susceptible to fogging, maximum transmission (including IR).
- Design-corrected field Fine stars in the center and on the edges.
- No residual aberration no permanent corrector in the optical path.
- No mirror shift : fixed primary → maximum stability in long exposure imaging.
Technical specifications
| Optical design |
Ritchey-Chrétien (hyperbolic mirrors) |
| Opening |
203 mm (8″) |
| Focal length |
1624 mm |
| Ratio f/ |
f/8 (≈ f/5.36 with reducer 0.67×) |
| Theoretical resolution |
0,58″ |
| Mirrors |
Quartz, reflectivity 94 % |
| Backfocus |
≈254 mm from back of tube / 159 mm from 2″ runner |
| Secondary obstruction |
85 mm |
| Focuser |
2″ double-speed monorail + 1.25″ adapter |
| Connection thread |
M90×1 |
| Dovetail |
2 x 395 mm Vixen bars (GP) |
| Tube diameter |
230 mm |
| Tube length |
580 mm (with focuser) |
| Weight |
≈8.25 kg (+0.5 kg extension rings) |
In the box
- RC 8″ f/8 telescope (203/1624)
- Focuser Monorail 2″ (with 1.25″ adapter)
- Two Vixen-style dovetail bars (GP)
- M90 extension rings
- Protective cap
In a nutshell
Visit TS-Optics GSO 8″ RC Pro is a high-end, affordable solution for astrophotographers looking for a stable, bright, full-field corrected instrument. With its optional accessories (corrector, reducer, OAG, filter wheel), it can easily be upgraded to advanced, high-quality setups.
