Ritchey-Chrétien optical tube TS-GSO RC 12 Truss

Ritchey-Chrétien optical tube TS-GSO RC 12 Truss

TS-Optics 12 "f/8 RC Telescope Ritchey-Chrétien with carbon tube
Teleskop-Service has optimized this 12" RC especially for astrophotography. The OTA comes with carbon trusses that have a thermal expansion of almost 0. The weight of the OTA is 24 kg and has a dovetail style rail Losmandy on both sides.

Our 12" f/8" RC astrograph illuminates a maximum field diameter of approximately 60 mm. Without corrector, 35 mm are possible. In the latter configuration, it has a pure mirror system without lenses. You do not need an IR cut filter and can use the full spectrum with a suitable astronomical camera.

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

♦ Hyperbolic primary and secondary mirror for a large, fully illuminated field of view.
♦ Astrophotography is possible with camera sensors up to 30 mm diameter without a corrector. For larger sensors, such as full frame size, Teleskop-Service offers ready-to-use corrector solutions.
♦ 99% high reflectivity dielectric coating on the primary and secondary mirror for an even brighter image.
♦ Significantly shorter cooling time due to open construction and ventilation of the active primary mirror.
♦ Internal baffles in the tube for even more contrast.
♦ High back focus for correctors, reducers and also binovisors.
♦ High quality 3" MONORAIL focusers with M77x0.75 female thread on the extension tube and M74x0.75 male thread connection and 2"/1.25" receptacles.

Astrophotography with the RC telescope:
Due to the large corrected field of view, you can, for example, use a DSLR up to APS-C format without corrector. Therefore, the RC is a pure mirror system for astrophotography. The images become ultra-sharp. To obtain images directly in focus, you will need the supplied M117x1 extension tubes. They are threaded between the telescope and the focuser, thus reducing back focus.

The generous back focus also allows you to attach correctors which we recommend when using at least full frame size sensors. You can also attach a focal reducer, thus further increasing the speed of the RC.

You can connect the camera through a 2" receptacle or screw it through the M77x0.75 female thread on the extension tube and the M74x0.75 male thread on the focuser. Suitable adapters can be found in the accessories section.

The 3" monorail focuser is a further development of the Crayford design. The load is not carried by four (often undersized) ball bearings, but on a stainless steel track in the base, which prevents tilting and bending even under high loads. Counterbalanced by a large knurled screw that centers the inner tube exactly on the rail, the load is evenly distributed along the rail surface.

Technical details of the focuser:

♦ Travel: ca. 80 mm
♦ Clear aperture: 68 mm
♦ Orientation: by solid and fixed steel rail
♦ 1:10 transmission for precise focusing
♦ 360 ° rotation
♦ Adaptation to 2" M68 female thread and (when unscrewed), fits directly into off-axis guide TS 2.5"

Quartz glass primary and secondary mirror with 99% reflectivity and quartz dielectric protective coating:
Quartz glass does not change its dimensions if temperature changes. When the temperature changes slowly during an exposure, other mirror substrates, such as Pyrex, tend to deform the mirror and thus change the focus. This problem does not exist for quartz glass mirrors. Therefore, the focus is better maintained, which is very important for long exposures. Both mirrors are coated with 99% reflectivity. The image is obviously brighter than that of telescopes with only 90% or 94% reflective coating.

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 to make a large field usable. With Schmidt-Cassegrains, you can see aberrations in the field even when working visually. Most of the time, Maksutov-Cassegrains are so slow that they are not suitable for astrophotography. RC telescopes have hyperbolic primary and secondary mirrors. They are more difficult to manufacture, but offer a significantly sharper field with fewer 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. Also, these telescopes have a Schmidt plate on the front that is prone to dewarping. The RC is a pure reflection system with no lens in the light path. Therefore, it can use full light even in the infrared range. The image is brighter and exposure times are shortened. The field of an RC telescope is coma-free by design and relatively flat.

No shift problem with TS RC telescopes:
Telescopes with focusing through a moving primary mirror often suffer from the "shift problem". The image shifts when focusing or even jumps. At this point, Meade and Celestron have the problem under control, but the effect is noticeable nonetheless. The TS RC telescopes do not have this problem, as their main mirror is fixed. Focusing is done by a high quality focuser. An additional advantage is the optimal distance between the primary and secondary mirror. This gives you the guarantee of the best possible image. If the primary mirror moves relative to the secondary mirror, you will practically never have the optimum distance.

General features:

The astrograph TS 12 "f / 8 Ritchey-Chrétien is a dream telescope for astrophotography.
♦ Aperture 12"/ 304 mm

focal length 2432 mm

♦ Focal ratio f / 8

♦ Hyperbolic primary and secondary mirror for very high sharpness on the optical axis and a large, well-corrected field for astrophotography

mirrors made of fused silica for stable focusing position

♦ Highly reflective 99% dielectric coating on the primary and secondary mirror for an even brighter image

faster cooling due to open construction and ventilation of the primary mirror

♦ Two dovetail style dovetail bars are supplied Losmandy, ideal for accessories such as telescopic sights or a piggyback camera mount

♦ Carbon lattice tube: more rigidity and better focusing stability for astrophotography

3" MONORAIL focuser with M77x0.75 female thread on the extension tube and M74x0.75 male thread connection and 2" / 1.25" reduction adapter

♦ Extension tubes for the focuser (2x 25 mm, 1x 50 mm) are supplied (picture on the left)

♦ RC correctors for larger sensors are optionally available

♦ New! The primary mirror and the M117 connector for the focuser are decoupled from each other. The focuser can be adjusted (tilted) independently of the primary mirror.

Technical specifications:

• Optical design: True RC with hyperbolic primary and secondary mirror.
• Aperture: 12"/ 304 mm
• Focal length: 2432 mm
• Focal ratio: f / 8
• Mirror Material: Low thermal expansion quartz primary and secondary mirrors
• Reflectivity: 99% reflectivity, non-fogging dielectric mirror coatings
• Rear focus: 285 mm from the M117 thread on the back of the tube - 179 mm from the 2" focuser connection
• Resolution: 0.38" (0.38")
• Tube: Carbon armor tube with 2 dovetails - level Losmandy
• Tube weight: 24 kg
• Tube diameter: ca. 485 millimeters
• Tube length: 850 mm without focuser
• Focuser: 3" M-LRN monorail focuser with micro transmission and 5 kg load capacity.
• Eyepiece side connection: 2" and 1.25"
• Additional threads: female thread M77x0.75 on the extension tube and male thread M74x0.75

Optical tube Ritchey-Chrétien TS-GSO RC 12 Truss