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Having a tough time trying to decide which mount your setup needs ? Read on to see if we can help shed some light for you !! 



What is the difference in telescope design (for amateurs) ?

Date: 10/09/2010

There are so many telescope designs out there it can be pretty confusing to figure out which to get. This table provides some technical details as to the fundamental design differences of each type of telescope. If you do notice any errors that should be corrected, please do let me know and contribute to making this information useful !

Hope this helps !!

Joo Beng




Reflector (Newtonian or Dobsonian)


Schmidt Cassegrain (SCT)

Schmidt Newton

Ritchey Chretien

Meade ACF


Primary element

Convex lens

Concave Spherical or Parabolic mirror

Spherical mirror

Spherical mirror

Spherical mirror

Hyperbolic mirror

Spherical mirror



Secondary element


Flat mirror

Spherical mirror

Convex mirror

Flat mirror

Hyperbolic mirror

Hyperbolic mirror



Correcting element



Positive meniscus

Schmidt corrector plate

Schmidt corrector plate


Corrector lens


Optical Flaws Chroma (for non-APO), Spherical aberration Coma, Spherical aberration (for Spherical mirrors) diffraction spikes, frequenct collimation     Minor coma Astigmatism, field curvature      

Aperture size


4"->16" 5" - 7" 8"-16" 6", 8", 10"   8"-16"    
Focal ratios f4-f/16 f/4-f/6 >f/15 ~f/10     f/10    
Telescope use Wide field Wide field Narrow field, Lunar, planerary, globular clusters, double stars. Deep Sky Wide field Deep Sky Deep Sky    
Price Range (OTA only) L-M L L M L H M    






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