Refractor:
Advantages:
- Great classic design
- No obstruction
- Good contrast
- Collimation almost never necessary
- No thermal degradation
Disadvantages:
- Expensive at larger apertures
- Unwieldy with large refractors
- Chromatic aberration and blurring if it not corrected
Newtonian:
Advantages:
- Cheap to manufacture
- Large apertures possible
- No chromatic aberration
- Good contrast
- Obstruction is fairly low
- Light
- Many variants are available
- Dobsonian construction possible
Disadvantages:
- Bildfehler je nach Öffnungsverhältnis
- Durch Obstruktion geringerer Kontrast als bei Refraktor gleicher Öffnung
- Da nicht geschlossen, sind thermische Luftströmungen möglich, die die Abbildung beeinträchtigen.
- Muss hin und wieder justiert werden
- Schmutzanfälliger als ein geschlossenes System
Schmidt-Cassegrain, ACF and Edge HD:
Advantages:
1. Short length 2. Very practical handling 3. Portable 4. Viewing is always comfortable 5. The SC thread allows a wide range of accessories to be connected 6. Instruments with a fork mount can be set up extremely rapidly
Disadvantages:
1. More expensive than a Newtonian of comparable aperture 2. Larger secondary mirror than with a Newtonian telescope
Maksutov:
Advantages:
- More expensive than a Newtonian of comparable aperture
- Short overall length
- Almost no chromatic aberration
- Closed system, therefore no thermal degradation
- Good correction of spherical aberration
- Very good contrast
- No spider vanes
- Inexpensive models available
Disadvantages:
-
Heavy due to the meniscus lens
- Long cool-down time
- Larger apertures (above 8") are rather expensive
- Obstructed by the secondary mirror
- Small fields of view due to aperture ratio of about f/13
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Achromatic refractors
Newton reflectors
Maksutov-Optic
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