Celestron C8 Optical Tube Assembly (CGE Dovetail) – 91024-XLT

The Celestron C8 Optical Tube Assembly (model 91024-XLT, also known as the C8-A) is the modern descendant of the original Celestron C8 that changed amateur astronomy when it launched in 1970. Its 203mm aperture and 2032mm focal length fit in a 432mm aluminium tube weighing just 5.67 kg.

The C8 balances portability, light grasp and price better than almost any telescope in its class. StarBright XLT coatings boost contrast and brightness, and Fastar compatibility allows very fast f/2 imaging with third-party accessories.

Modern Telescopes is an authorized Celestron distributor in India. We import the C8 directly, supply it with a GST invoice, and can pair it with the right mount and accessories.

Key features

• 203mm (8") aperture – gathers 843× more light than the human eye; limiting magnitude 14
• 2032mm focal length at f/10 – high image scale for the Moon, planets and small deep-sky targets
• 0.57 arcsecond resolution (Dawes) – sharp detail on planets and close double stars
• StarBright XLT coatings – up to 97.4% transmission through the corrector for brighter, higher-contrast images
• Fastar compatible – swap the secondary mirror for a third-party lens to image at f/2
• Highly portable – 432mm long and 5.67 kg, quick to carry and set up
• Aluminium tube – durable, lightweight construction
• CGE dovetail bar – fits Celestron CGEM II, CGX and other mounts with CGE / Losmandy-style saddles
• Accessories included – 25mm eyepiece (81×), 6x30 finderscope, 1.25" star diagonal, 1.25" visual back

Schmidt-Cassegrain optics and StarBright XLT

A Schmidt-Cassegrain folds a long light path into a short tube. Light passes through a thin corrector plate, reflects off the primary mirror, then off a secondary mirror and back through a hole in the primary. That is how the C8 packs 2032mm of focal length into a 432mm tube.

Celestron's StarBright XLT system improves light throughput in three ways:

• Enhanced multi-layer mirror coatings – aluminium overcoated with quartz and titanium dioxide layers, tuned for both visual and imaging use
• Multi-layer anti-reflection coatings – magnesium fluoride and hafnium dioxide on the corrector for a wider usable band
• Water-white glass corrector – higher-transmission glass instead of soda-lime, reaching an average 97.4% transmission once coated

The result is brighter, higher-contrast views of the Moon and planets as well as faint galaxies and nebulae.

Observing and imaging configurations

The C8 adapts to different targets depending on what you attach.

Celestron states that Fastar at f/2 shortens exposures to about one twenty-fifth of those needed at f/10, so galaxies and nebulae can be captured in around 30 seconds. A standard SCT has a curved field, so stars may soften toward the edges on large sensors – the EdgeHD 8 is the flat-field alternative.

Technical specifications

All figures from Celestron's official product page (source).

In the box and recommended add-ons

What's in the box: C8 optical tube with CGE dovetail bar, 25mm eyepiece, 6x30 finderscope, 1.25" star diagonal, 1.25" visual back.

At 5.67 kg, the C8 is light enough for a wide range of equatorial mounts. Leave payload headroom for cameras and accessories when imaging.

Who the C8 is for

• First serious telescope buyers who want real aperture in a tube they can carry with one hand
• Schools, colleges and science centres needing a dependable, easy-to-handle telescope for labs and public nights
• Planetary and lunar observers who want sharp views of Jupiter, Saturn, Mars and the Moon
• Travelling observers taking a compact setup to dark-sky sites

Why buy from Modern Telescopes

• Authorized distributor of Celestron, PlaneWave, Software Bisque and other global brands in India
• Direct import with proper GST invoice and input credit for registered businesses
• Complete observatory solutions: telescope, mount, imaging camera and motorized dome, supplied and installed
• Institutional procurement supported, including supply through GeM
• Pan-India delivery, installation support and after-sales service from Pune, Maharashtra

Contact: Modern Telescopes, MSR Queenstown, Chinchwad, Pune, Maharashtra 411033 · +91 85540 01525