Телескопы катадиоптрические

Planetary observations

— this category includes models designed to observe space objects located at a relatively short distance — primarily planets (hence the name), as well as the Moon, comets, asteroids, etc. Another option for using such telescopes is survey observations of star clusters, nebulae, etc. Anyway, such an application does not require a high magnification factor. But a wide field of view (characteristic of low magnifications) is very important, both for the mentioned survey observations and in the light of the fact that some objects of observation can move quite quickly across the sky, and at small viewing angles they would constantly be lost from sight. Thus, "planetary" telescopes have a relatively low degree of magnification and lens size; usually, they refer to refractors (see "Design").