No abstract

The optical design of a mirror telescope with a free aperture of 3.5 m is described. Observations can be made in the Cassegrain (RC) focus f/8, in the direct focus f/3, and in the coudé focus f/30. The results of ray tracing in the form of spot diagrams are dealt with. Some technological problems are discussed.

No abstract

The design concept of a high speed stellar spectrograph for gratings up to a ruled length of 128 mm and for dispersions from 80 A/mm to 20 A/mm is described. It consists of a mirror collimator and two exchangeable mirror cameras. The impinging and diffracted bundle of light is corrected by means of concentric menisci which are exchanged together with the camera. Information is given about design details and the corrections obtained.