Glossary | Telescopes | Optics | Type of build
Mirror telescope or refracting lens telescope? Schmidt-Cassegrain or Maksutov? Anyone faced with these agonizing questions before buying a telescope needs to find out about the advantages and disadvantages of the different design types.
Refracting lens telescope:
- Fraunhofer Achromat: classic principle of a refractor, but with chromatic aberration.
- ED Apochromat: two- or three-lens refractor with an ED lens that reduces the most chromatic aberration and ensures maximum contrast. Among these refractors there are also some very well-corrected three-lens optics that correct chromatic aberration and field curvature and so are very suitable for astrophotography.
Reflector mirror telescope
- Newtonian Reflector: classic telescope, named after Isaac Newton, with a main mirror and a secondary mirror. Simple and proven system.
- Maksutov Cassegrain: system consists of a main mirror and a secondary mirror, and a meniscus correction lens.
- Schmidt-Cassegrain: similar to the Maksutov, but instead of the correction lens, a Schmidt plate sits in front of the optics in order to correct chromatic aberration.
More information:
ACF-Cassegrain
Meade's ACF optical design eliminates the typical aberrations of all mirror optics.
Achromat
An achromatic is a refracting telescope (refractor), which consists of two lenses. It is the classic refractor design.
Apochromat
Refractors with little chromatic aberration.
Astrograph
Telescopes that are suitable exclusively for astrophotography.
Cassegrain
This telescope consists of a parabolic primary mirror with a central hole and a hyperbolic secondary mirror. In this way the construction can be kept as short as possible.
EdgeHD-Cassegrain
Celestron’s aplanatic EdgeHD optics revolutionized astroimaging.
Maksutov
Maksutov-Cassegrain telescopes have a compact design, but a very long focal length. At the front there is a Maksutov lens. These telescopes are very well suited for planetary observing.
Maksutov Newtonian
Maksutov Newtonian telescopes are built like a classic Newtonian telescope, but have a Maksutov corrector lens at the telescope opening. With this, coma is eliminated. The telescope has excellent imaging capabilities.
Newton
Reflector telescope with a secondary mirror at the beginning of the tube which redirects light to one side.
Schmidt Newtonian
A Schmidt Newtonian telescope is constructed like a Newtonian telescope, but includes a Schmidt corrector plate. Thus, this telescope is a closed system and there is no air turbulence in the tube.
Schmidt-Cassegrain
A reflector telescope with a particularly compact design but a long focal length. In addition to two mirrors, it has a Schmidt corrector plate at the front.
Solar H-Alpha
With H-alpha telescopes you can observe prominences, flares and filaments on the Sun. Additionally, these telescopes have an etalon filter and a blocking filter. Caution: you can also buy versions without the blocking filter. You should never use these without a blocking filter.
Solar calcium
Calcium K solar telescopes make the lower atmospheric layers of the chromosphere visible at 393nm. This blue short-wave region shows other equally interesting details of the Sun. These telescopes are popular for use in photography.