Large telescopic optical system with null alignment optics

The invention constituting the optical system is arranged in the annular mirror and the primary mirror formed on the outer sub-mirror and check the optical alignment for the entire optical path of the large-diameter reflector. It is designed to null the system to match the optical wave front of the main path and a predetermined band-shaped surface of the light reflected from the ring-shaped mirror. The channel alignment system has the same channel using a small reflecting mirror so reduced as well as the overall weight lighter appearance benefits of the ring-shaped sub-mirror to the outside. Large reflecting telescopes, optical alignment, optical channel