TS-Optics GSO 8″ RC Pro Carbon 203/1624 – Focus Stability for Astrophotography
The Ritchey-Chrétien TS-Optics GSO 8″ (203 mm, 1624 mm, f/8) with carbon tube is the ideal instrument for demanding astrophotography: more stable focus in the face of thermal variations, rapid cooling thanks to the open tube, and fine stars in a field naturally corrected by the RC design (hyperbolic mirrors).
Highlights
- Genuine RC coma-free, relatively flat field, excellent sharpness across the entire sensor.
- Carbon tube almost zero expansion → very stable focus in long exposures.
- Quartz mirrors (fused silica) with 94 % reflectivity brighter, higher-contrast image.
- Open construction : bringing to temperature faster, less internal turbulence.
- Generous backfocus (≈159 mm at 2″) Easily integrates corrector, gearbox, OAG and filter wheel.
- MONORAIL 2″ Focuser double speed: greater rigidity than a Crayford, 360° rotation, graduation, motorization possible.
- Double dovetail Losmandy below, Vixen above → easy accessory mounting.
Astrophotography
Without corrector, sensors up to APS-C are perfectly usable. For full format, a dedicated RC corrector is recommended. Visit CCD47 reducer 0.67× changes the focal length from approx. 1624 mm to ≈1088 mm and the aspect ratio from f/8 to f/5.36, reducing exposure times by more than 50 % and opening up framing for nebulae and diffuse galaxies.
Why a carbon tube?
Mass changes only marginally (~300 g), but the increased firebox stability when temperature drops is determining: metal → contraction → frequent refocusing; carbon + quartz mirrors → refocusing. focus that hardly moves, essential for long imaging sessions and cool nights.
RC vs SCT/Mak advantages
- No Schmidt blade less fogging, better transmission (including near-IR).
- Path 100 % reflective no permanent glass → more photons to the sensor.
- No mirror shift Fixed primary, MAP via rigid external focuser.
In the box
- 8-inch f/8 Carbon Fiber RC Telescope
- MONORAIL 2" Focuser (+ 1.25" Adapter)
- Losmandy & Vixen dovetails
- M90 extension rings
- Protective cap
Aesthetic note some photos show a black front ring; the version supplied has a red front ring.
In a nutshell
The TS-Optics GSO 8-inch RC Carbon combines the precision of a true RC, the stability of a carbon tube and simplicity of integration (long backfocus, double dovetail, rigid focuser). A premium choice for those who want sharp long exposures and an upgradeable setup (corrector, gearbox, OAG, filter wheel) without compromise.