TS-Optics GSO 8" Ritchey-Chretien Pro RC Telescope 203/1624 mm OTA

TS-Optics GSO 8" f/8 RC Ritchey-Chrétien Telescope

Most large professional telescope are constructed according to the RC principle. Until recently, these telescopes were unaffordable for amateurs. RC telescopes from Teleskop-Service are primarily aimed to amateur astronomers with photographic interest. These telescopes are perfectly suited for high-resolution astrophotography. Of course, an RC can also be used for visual observing. Here, the large corrected field of view is noticeable, too. In total, the stars are sharper than, for example, in a Schmidt-Cassegrain.

The advantages of the TS-Optics RC Telescopes at a glance:

Hyperbolic primary and secondary mirror for a large fully corrected field of view.

Astrophotography with camera sensors up to 30 mm diameter possible without corrector. For larger sensors, like full-frame size, Teleskop-Service offers ready-to-use corrector solutions.

94% enhanced reflectivity on main and secondary mirror for an even brighter image.

Significantly shorter cooling down time through open construction

Internal baffles in the tube for even more contrast.

High back focus for correctors, reducers and also binoviewers.

High-quality 2" MONORAIL focuser with 2" and 1.25" receptacle.

Due to a redesign of the baffle tube, problems with stray light no longer occur. Nevertheless, the illumination is still very good. Sensors up to full frame format can be used.

Astrophotography with the TS-Optics 8" RC telescope:

Better and sharper astrophotos without corrector with shorter exposure times. This is exactly what this RC 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 from the use of full-frame sensors. You can also connect a focal length reducer, thus further increasing the light intensity of the RC.

Astrophotographic results obtained with this telescope on Astrobin

The RC telescopes are very well suited for astrophotography. Here you can find some astrophotographs made with this telescope model: Link to Astrobin

0.67x CCD reducer for astrophotography

The CCD47 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 moderate exposure times.

The 2" MONORAIL focuser - more than a Crayford:

The Monorail focuser combines the ease of movement of a Crayford focuser with the stiffness of a rack-and-pinion focuser. Thus astrophotography becomes a success.

Massive stainless steel bar instead of small ball bearings for more stiffness.

No tilting anymore when locking the drawtube.

360° rotation for optimal object alignment

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

Primary and secondary mirror of quartz glass with 94% enhanced reflectivity:

Quartz glass does not change its dimensions if temperature changes. When the temperature changes slowly during an exposure, other mirror substrates, like Pyrex, tend to a deformation of the mirror and thus to a shift of the focus. This problem does not exist for mirrors of quartz glass. Thus the focus is better maintained which is very important for long exposures. Both mirrors are coated with 94% reflectivity. The image is obviously brighter than the one of telescopes with only 90% reflection layer.

The advantages of TS RC telescopes for astrophotography:

The TS RC astrographs are true Ritchey-Chrétien telescopes. Maksutovs and Schmidt-Cassegrains have spherical mirrors and need correctors for making a large field usable. With Schmidt-Cassegrains, you can see the aberrations in the field even when working visually. Most times, Maksutov-Cassegrains are so slow that they are not suitable for astrophotography. RC telescopes have hyperbolical primary and secondary mirrors. They are more difficult to manufacture, but offer a significantly sharper field with less aberrations throughout the field.

Why is the RC Telescope superior to Schmidt-Cassegrain telescopes with correctors:

Celestron EHD or Meade ACF telescopes need a corrector. Additionally, these telescopes have a Schmidt plate at the front side which is prone to dew. The RC is a pure reflection system without lenses in the light path. Thus you can use the complete light even in the infrared range. The image is brighter and the exposure times get shorter. The field of an RC telescope is coma-free by design and relatively flat.

No shifting problem with TS RC telescopes:

Telescopes with focusing via movable primary mirror often suffer from the shifting problem. The image shifts while focusing or even jumps. By now, Meade and Celestron have the problem under control, but the effect is noticable nonetheless. TS RC telescopes do not have this problem, as their primary mirror is fixed. Focusing is done via a high-quality focuser. An additional advantage is the optimal distance from primary to secondary mirror. This gives you the guarantee of the best possible image. If the primary mirror moves relatively to the secondary, you will practically never have the optimal distance.

Adjusting the RC telescope

We recommend the TSRCKOLLI or an collimating telescope for adjusting the telescope. These tools are linked in the "Cleaning & Collimating" section.

Video with information about RC telescopes

On our YouTube account you will find a video about the characteristics of the Ritchey-Chrétien telescopes in general and the features of the GSO RCs in particular, as well as suggestions for accessories:

Astrophotographic results obtained with this telescope on Astrobin

The RC telescopes are very well suited for astrophotography. Here you can find some astrophotographs made with this telescope model: Link to Astrobin

Astrophotos through the TS 8" RC:

M92 - Reinhard I.
In the section (remark: "Recommended Accessories"), besides the flattener, two 0.67 x reducers are also offered. I would like to point out to you that your TS Photoline Reducer 0.79 x (TSRed279) also gives excellent results with the 8" RC format, giving an interesting compromise between detail and speed with a focal length of about 1300 mm.

M27 - C. Frere

Cameras: Atik383L+ for H-Alpha and O-III

Farbe/Color: QHY8L

M20 - Hamish Thava

L-RGB

Camera: Starlight SXVR-H694

Filter: Baader L-RGB

Mount: Skywatcher EQ6 Synscan

NGC891 - Wolfi Ransburg

Camera: ATIK 4000 Mono

no corrector

12x 12min

Andy Murner

Moon (valley in the moon alps)

DMK Camera from Imaging Source

Photographer: Reg Pratt (San Franzisco, USA)

Object: Coma Cluster (Abell 1656)

Telescope: TS-Optics 8" RC (TSRC8M)

Focuser: PrimaluceLab Esatto Focuser 2" (PLLEST2-B)

Rotator: Pegasus Falcon Rotator (PEG-ROT-FALCON)

Corrector: TS-Optics 2" CCD Reducer 0.67x (CCD47)

Filter wheel: ZWO USB filter wheel for 7x 2" filters (ZWOEFW7X2)

Filters: TS-Optics LRGB (TSLRGBS2)

Imaging camera: ZWO ASI2600MM (ASI2600MM-P)

Mount: iOptron GEM45 (IO7603A)

Photographer: Anders H. Langhoff (Skanderborg, Denmark)

Object: Rosette B, part of the Rosette Nebula (NGC 2246)

Telescope: TS-Optics 8" RC (TSRC8M)

Motor focus: ZWO EAF motor focus system with 5 V USB supply (ZWO-5V-EAF-A)

Filter wheel: ZWO USB filter wheel for 7x 2" filters (ZWOEFW7X2)

Filters: Antlia SHO 7 nm nebula filter set, 36 mm unmounted (SHO-7NM-36)

Imaging camera: TS-Optics ToupTek MONO Astro Camera 2600MP (TS2600MP)

Mount: Skywatcher EQ6-R (EQ6-R)

Photographer: Michael Kalika (Rishon Le-Tzion, Israel)

Object: Wirlpool Galaxy (Messier 51)

Telescope: TS-Optics 8" RC (TSRC8M)

Imaging camera: ZWO ASI2600MC Pro (ASI2600MC-P)

Mount: iOptron CEM70G (C70AG)

Off axis guider: ZWO OAG (ZWOOAG)

Guiding camera: Starlight Xpress Lodestar X2 (improved alternative: LodestarPro)

Photographer: Michael Kalika (Rishon Le-Tzion, Israel)

Object: Waxing Crescent Moon

Telescope: TS-Optics 8" RC (TSRC8M)

Imaging camera: ZWO ASI2600MC Pro (ASI2600MC-P)

Mount: iOptron CEM70G (C70AG)

Safety informations: PDF Download