GSO Ritchey-Chrétien 406/3250 Truss Tube OTA

GSO Ritchey-Chrétien 406/3250 Truss Tube OTA

Until now, real RC telescopes were not only known for their good optical data, but mainly for their high price. The US manufacturer "Astro-Tech" contracted GSO, which is known for very good mirror optics, to produce true RC (Ritchey Chrétien) telescopes. The result are astrographs, far above the level of typical Schmidt Cassegrains, at an affordable price. They provide very good imaging on axis and in the field, without the use of additional correctors, so RC telescopes are used primarily for astrophotography. These instruments are true RC optics with hyperbolic primary and secondary mirrors, both made of fused silica. The mirrors have excellent specularity with up to 99% reflectivity. Thanks to the open tube, the system cools down much faster than comparable Schmidt Cassegrains.

These RC telescopes (except the 6" model) illuminate full format chips (24x36mm), but with such large chips a field flattener is recommended. Smaller chips like the APS-C format do not need any intermediate optics. The imaging is completely free of chromatic aberration and the resolution is much higher than most apochromatic refractors at this price level. They have a generous back focus that allows the use of extensive accessories. Note, however, that you will need extensions to achieve focus. For easier collimation of the system, the secondary has a central marker.

Scope of delivery:  

• 16"-f/8-RC astrograph - with truss tube.
• Losmandy level prism rail
• Main mirror vent