GSO - Ritchey Chretien 12'' f/8 Optical Tube - Carbon Fibre Tube

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 GSO 12" RC f/8 Astrograph can illuminate a field diameter of max. ca. 60mm (including optional RC corrector). Without corrector, the useable field has ca. 35mm diameter. Here, you have a pure mirror system, that can be used without UV/IR cut filter. Most of the CCD cameras are sensitive in this spectral range. The image is absolutely free from chromatic aberrations and the resolution is higher than most apochromatic refractors in this price range.

Due to the large corrected field of view, you can, for example, use a DSLR up to APS-C format without corrector. Thus the RC is a pure mirror system for astrophotography. The images become ultrasharp. For imaging dirctly in the focus, you will need the M90x1 extension tubes which are supplied. They are threaded between telescope and focuser, thus reducing back-focus.

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

The 3" mono rail 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 evenly across the rail´s surface. You can connect the camera via 2" receptacle or thread it via the female M69x1 thread of the focuser.

The primary mirror is fixed in its precisely machined mirror cell. Collimation of the telescope is done through the secondary mirror. Collimation is rather easy and can even be done by an inexperienced amateur astronomer - we do however recommend to take your time with the collimation!

Characteristics:

• Hyperbolic primary and secondary mirror for a large fully illuminated field of view
• Astrophotography with camera sensors up to 35mm diameter possible without corrector.
• 99% dielectric high-reflectivity coating on main and secondary mirror for an even brighter image
• Significantly shorter cooling down time through open construction and active primary mirror ventilation
• Internal baffles in the tube for even more contrast
• Long back focus for correctors, reducers and also binoviewers

Delivery:

• 12" f/8 RC astrograph OTA
• High-quality 3" MONORAIL focuser with M69x1 connection thread and 2" / 1¼" receptacles.
• 2 tube rings
• Dovetails Losmandy style