File:Telescope cassegrain principe.png

Schéma de principe du télescope de Cassegrain.

Les rayons parallèles, venant de l'« infini », sont focalisés par un miroir parabolique ou sphérique. Puis, ils sont déviés par un miroir hyperbolique et passent par un trou du premier miroir, ce qui permet d'avoir une grande distance focale tout en ayant un instrument compact. Ce schéma est partiel.

Sketch to explain the principle of the Cassegrain telescope.

The parallel beams, coming form a far distance ("infinite"), are focalised by a parabolic or spherical miror. Then, they are deviated by a hyperbolic miror, which allows abig focal distance in a compact instrument. This is a partial sketch.

Auteur/author : Christophe Dang Ngoc Chan (Cdang

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