Celestron C9.25 Optical Tube Assembly (CGE Dovetail) – 91027-XLT

The Celestron C9.25 Optical Tube Assembly (model 91027-XLT) is a 235mm Schmidt-Cassegrain often called the "just right" size – more aperture than an 8", yet far easier to handle than an 11". Its 2350mm focal length fits in a 559mm aluminium tube that weighs just 9.07 kg.

The C9.25 is well regarded for sharp, high-contrast planetary and lunar views. Celestron's StarBright XLT coatings boost light transmission, and Fastar compatibility opens the door to very fast f/2 imaging with third-party accessories.

Modern Telescopes is an authorized Celestron distributor in India. We import the C9.25 directly, supply it with a GST invoice, and can pair it with the right mount and accessories.

Key features

• 235mm (9.25") aperture – gathers 1,127× more light than the human eye; limiting magnitude 14.4
• 2350mm focal length at f/10 – high image scale for planets, the Moon and small deep-sky targets
• 0.49 arcsecond resolution (Dawes) – splits close double stars and shows fine planetary detail
• 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
• Compact and light – 559mm long and 9.07 kg, easy to carry and set up
• Aluminium tube – durable yet lightweight construction
• CGE dovetail bar – fits Celestron CGEM II, CGX and other mounts with CGE / Losmandy-style saddles
• Accessories included – 25mm eyepiece (94×), 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 enters through a thin corrector plate, reflects off the primary mirror, then bounces off a secondary mirror back through a hole in the primary. That is how the C9.25 packs 2350mm of focal length into a 559mm tube.

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

• Enhanced multi-layer mirror coatings – aluminium overcoated with layers of quartz and titanium dioxide, with fairly flat reflectivity 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 of 97.4% transmission once coated

The result is brighter images with better contrast, which helps on subtle planetary detail as well as faint galaxies and nebulae.

Observing and imaging configurations

The C9.25 adapts to different targets depending on what you attach.

Celestron states that Fastar at f/2 cuts exposure times to about one twenty-fifth of those needed at f/10, so galaxies and nebulae can be captured in exposures as short as 30 seconds. Because a standard SCT has a curved field, imagers using large sensors may see softer stars toward the edges – the EdgeHD 9.25 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: C9.25 optical tube with CGE dovetail bar, 25mm eyepiece, 6x30 finderscope, 1.25" star diagonal, 1.25" visual back.

At 9.07 kg, the tube suits mid-weight equatorial mounts. Leave payload headroom for cameras and accessories when imaging.

Who the C9.25 is for

• Planetary and lunar observers who want sharp, high-magnification views of Jupiter, Saturn and Mars
• Schools, colleges and science centres needing a capable, easy-to-handle telescope for labs and public nights
• Amateurs upgrading from a C8 who want more aperture without a heavy mount
• Planetary imagers using high-speed cameras at f/10 or with a Barlow

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

Frequently asked questions

What is the price of the Celestron C9.25 in India? Prices move with exchange rates and import duties. Contact Modern Telescopes for a current quote with GST invoice, or request an institutional or GeM quotation.

C9.25 vs EdgeHD 9.25 – what's the difference? Both have 235mm aperture and 2350mm focal length. The EdgeHD adds a flat-field corrector, mirror clutches and cooling vents for wide-field imaging on large sensors. The C9.25 is the more affordable choice for visual and planetary use.

C9.25 vs C8 – is the extra aperture worth it? The C9.25 collects about a third more light than an 8" and resolves finer detail, while staying compact enough to carry and mount easily.

Does the C9.25 come with a mount? No. This is the optical tube assembly with a CGE dovetail. Pair it with a mount such as the Celestron CGEM II or CGX.

What magnification does the C9.25 give? The included 25mm eyepiece gives 94×. The useful range is 34× to 555×, depending on eyepiece and sky conditions.

Can I do astrophotography with the C9.25? Yes. It excels at planetary and lunar imaging at f/10. Add the Reducer-Corrector for f/6.3, or a third-party Fastar lens for f/2 wide-field deep-sky imaging.

How much does the C9.25 weigh? The optical tube weighs 9.07 kg (20 lbs). It is 559mm long and 271.78mm in diameter.