Types of Catadioptric Telescopes

There are 3 types of catadioptric telescopes as described below:

  • The most popular of the catadioptric telescopes is the Schmidt-Cassegrain which is a full aperature design (see below)

1. Dialytic

  • The oldest type of catadioptric telescopes but have since been replaced by the 2 other types
  • Based on a lens system which was widely air spaced designed to save at that time on the expensive flint glass used
  • consisted of a single refractor objective which was combined with a silver backed negative lens

2. Full Aperature

  • This system is based on a corrector plate lens placed in front of a spherical mirror which serves to bend the light which is then reflected by the mirror allowing imaging at infinity
  • This system of bending and folding the light allows for an equivalent focal length in a shorter tube system achieving faster F ratios needed for astrophotography

Examples: Schmidt-Cassegrain, Schmidt Newtonian, Maksutov-Newtonian, Maksutov-Cassegrain

 3. Sub-Aperature

  • The advantage of this system is that less glass is required therefore contributing to less weight however the requirements for fabrication and alignment are more stringent

Examples: Classical Cassegrain, Dall-Kirkland, Ritchey-Chretien, Field-Maksutov and Klevtsov, Gregorian sub-aperture Schmidt corrector, Celestron Edge


Web Site Map:
Astronomy Notebook
The Moon
Images And Videos
Equipment and Setup
Notes on Equipment
An Overview Of The Methods In Astrophotography