Part 2: Optical Types

Refractor Telescopes

Probably the most recognisable style, a Refractor telescope features a lens at one end and the eyepiece at the other, similar to a pair of binoculars or a spotting scope. The simplicity of this design and relatively low cost makes Refractors popular for beginners.

  • Advantages: simple design makes them easy to set up, use and maintain.

  • Disadvantages: tend to have a smaller aperture for the price, making them less suitable for viewing fainter objects.

  • Great for: lunar and planetary viewing, and can see some binary stars.

Reflector Telescopes

This type of scope uses mirrors rather than a lens, which results in a larger aperture for the price. The larger aperture enables most Reflector telescopes to be used for deep sky observation in addition to planetary and lunar viewing.

  • Great for: lunar and planetary viewing, and can see some binary stars.

  • Advantages: has the largest apertures for the price range, making more suitable for fainter objects.

  • Disadvantages: the open tube can allow dust to settle on the mirror, even when covered. This can increase the maintenance required.

Cassegrain (or catadioptric) Telescopes

A Cassegrain (either Schmidt- or Maksutov-Cassegrain) uses a combination of lenses and mirrors to provide a large aperture and long focal length for excellent light gathering ability and higher magnifications.

  • Advantages: focal length much longer compared to size of scope, and the enclosed design reduces maintenance. The optical design results in a compact size and high power.

  • Disadvantages: higher price point than equivalent reflectors.