A few weeks ago I had the opportunity to purchase a second hand Astrosib RC250, a real Ritchey-Chrétien telescope. This 10″ RC f/8 f=2000mm delivers a true flat field as it’s supposed to do. This telescope is of Russian make. The looks are probably not the most exciting around but this is more than compensated by the excellent quality optics. Furthermore it is built like a (T-34) tank. I think I will enjoy using this telescope very much.
Here you can see the first three trials I took with the Astrosib. The pictures were taken on May 5th and 6th. There were some clear skies but the seeing was not that great, especially with the sample of the group of galaxies in Draco, with NGC5985 being the most photogenic. M81 and NGC5985 are luminosity frames with an Astronomik CLS filter; IC5070 was shot in H-alpha with an Astronomik 7nm filter. All pictures were taken, using an AstroPhysics reducer, focal length 1500mm at f/6.
- M81, Bode’s galaxy: 20x10min L (CLS)
- NGC5981, 5982 & 5985 in the constellation of Draco: 10x10min L (CLS)
- IC5070, part of the Pelican nebula: 9x10min Ha