Celestron C8 8″ XLT Schmidt-Cassegrain Optical Tube Assembly


  • 8″ Schmidt-Cassegrain Optical Tube Assembly
  • Celestron’s premium StarBright XLT coatings
  • Aluminium Optical Tube
  • 2032 mm focal length (f/10)
  • 25 mm eyepiece included (81x)
  • 1.25″ visual back for use with 1.25″ accessories
  • 6×30 finderscope to help accurately find objects
  • Star diagonal provides more comfortable viewing position when observing objects that are high in the sky
  • CG-5/Vixen or CGE/Losmandy dovetail rail options
Starbright XLT Coatings

Availability: We are currently out of stock of this item, however one of our authorised dealers may have it in stock. Please check our dealer locator to find your nearest stockist.

Category: SKU: 91020XLT Tag:


This 8″ aperture optical tube assembly (OTA) is the most popular size of Celestron’s Schmidt-Cassegrain range.  It features Celestron’s StarBright XLT coatings on the corrector plate for maximum light transmission. The telescope has a 2032mm focal length (f/10) making it a good overall performer on a range of celestial objects.

The telescope comes with a star diagonal for more comfortable viewing of high altitude objects and a 25mm Plossl eyepiece which gives 81x magnification. A 6×30 finderscope to help locate objects completes the package.

There are two dovetail bar versions of the C8 available – a CG-5/Vixen style and a wider CGE/Losmandy style. Both models are identical optically and with what is included in each package.

Optical DesignSchmidt-Cassegrain
Aperture203.2mm (8″)
Focal Length2032mm (80″)
Focal Ratiof/10
Focal Length of Eyepiece 125mm (0.98″)
Magnification of Eyepiece 181x
Star Diagonal1.25″ Star Diagonal
Optical TubeAluminum
Highest Useful Magnification480x
Lowest Useful Magnification29x
Limiting Stellar Magnitude14
Resolution (Rayleigh)0.69 arc seconds
Resolution (Dawes)0.57 arc seconds
Light Gathering Power (Compared to human eye)843x
Secondary Mirror Obstruction64mm (2.5″)
Secondary Mirror Obstruction by Diameter31%
Secondary Mirror Obstruction by Area9.77%
Optical CoatingsStarBright XLT
Optical Tube Length432mm (17″)
Optical Tube Diameter238mm (9.37″)
Optical Tube Weight12.5 lbs (5.67 kg)
DovetailVixen/CG-5 Dovetail bar & CGE/Losmandy available

Additional information

Weight10 kg
Celestron Technology


Optical Design