Celestron Nexstar Evolution 8 OTA
C8 Optical Tube Assembly as used in the best selling Celestron Evolution 8. Sold without eyepiece, visual back or finderscope. Ideal if you have a damaged telescope or want to upgrade to the "magic" 8 inch aperture.
Warranty: 2 years
All optical surfaces are coated with Celestron’s high efficiency StarBright® multi-layered coating group. These tube assemblies are equipped with the same dovetail mounting bar used on the CGE and Advanced Series for easy attachment to a variety of popular mounts.
• 8" Schmidt-Cassegrain Optical Tube Assembly
• Aluminum Optical Tube
• Celestron's premium StarBright XLT coatings
• 2032 mm focal length (f/10)
• Visual back (not included) allows for use with 1.25" accessories
• Star diagonal (not included) provides more comfortable viewing position when observing objects that are high in the sky
• Includes dovetail rail compatible with Vixen/Advanced Series mount
OPTICAL DESIGN : Schmidt-Cassegrain
APERTURE: 203.2 mm (8 in)
FOCAL LENGTH : 2032 mm (80 in)
FOCAL RATIO : 10
FINDERSCOPE : Not included
OPTICAL TUBE: Aluminum
STAR DIAGONAL : not included
OPTICAL COATINGS : StarBright XLT
SECONDARY MIRROR OBSTRUCTION : 2.5 in (63.5 mm)
SECONDARY MIRROR OBSTRUCTION BY AREA : 9.8 %
SECONDARY MIRROR OBSTRUCTION BY DIAMETER: 31.3 %
OPTICAL TUBE LENGTH : 17 in (431.8 mm)
OPTICAL TUBE WEIGHT : 12.5 lb (5.67 kg)
DOVETAIL COMPATIBILITY : CG-5 Mount
The C8 was the revolutionary instrument of modern amateur astronomy. It is portable, compact, enough aperture for deep-sky detail, enough aperture for clear planetary detail and colour, and simple to use. It has the convenience of a fixed focusing position at the rear of the tube assembly, and has more after-market accessories made for it than any other telescope in history.
The modern C8 OTA (Optical tube assembly), is even better value for money than it ever was. Its performance, due to consistent optics, baffle system and the excellent XLT coatings makes this an impressive deep-sky performer. It is no longer considered by optical enthusiasts as a reasonable telescope that is adequate for most aspects of astronomy, but excels at nothing. Today, the improvements to the Celestron SCT optics over the last seven years have transformed it into a telescope that can outperform a similar aperture Newtonian for deep-sky contrast, and can reveal planetary detail using modern video imaging techniques that were not detectable with instruments of twice the aperture, as little as twenty years ago.
The C8 is the ultimate medium aperture grab-and-go telescope. 8" is considered by many to be the "magic aperture". Its the aperture at which globular clusters can be seen to be fully resolved, subtle colour begins to be obvious on the planets, and many deep-sky objects show obvious structure, rather than just presence. All this plus compactness and portability is the reason why Celestron have experienced such a success with this iconic telescope. The C8 OTA can be fitted to the Celestron CG5, CGEM, Skywatcher EQ5, HEQ5 and EQ6 mounts and Losmandy. It sits easily in the jaws of many simple manual alt-azimuth mounts, and can fit into a small sports hold-all.
Photographically it is a diffraction limited 2030mm f/10 telephoto, a 4060mm f/20 telephoto by adding a 2X Barlow, or a 1279mm f/6.3 telephoto by adding the Celestron f/6.3 focal reducer lens.
Budget for the SCT t-adapter, the f/6.3 focal reducer, a 2" star diagonal so 2" eyepieces can be used, a Neutral Density filter or Polariser for the moon, the Celestron dewshield, and the Baader UHC and Oxygen III filters.
With any Cassegrain telescope you will have to consider the affect dew fall. The cheapest solution is a lens hood but when dew is a real problem then heater straps will evaporate dew off.
- Optical Design
- Schmidt Cassegrain
- 8 inch
- Focal Length
- 2032 mm
- Focal Ratio
- Optical Coatings
- Starbright XLT Coating
- Optical Tube Length (mm)
- 17 inch
- Two Years
- Normally on display?
- Yes - But Check First If Making A Special Journey!