Celestron EdgeHD 9.25" Optical Tube Assembly (CGE Dovetail) – 91040-XLT

The Celestron EdgeHD 9.25" Optical Tube Assembly (model 91040-XLT) delivers Celestron's flagship aplanatic optics in a tube light enough to carry. Its 235mm aperture and 2350mm focal length sit in a 559mm tube weighing just 9.53 kg.

EdgeHD corrects both coma and field curvature, so stars stay pinpoint to the edge of large camera sensors. The 9.25" primary is also known for its slower mirror and sharp planetary performance. Many imagers see it as the best balance of aperture, image quality and portability in the EdgeHD range.

Modern Telescopes is an authorized Celestron distributor in India. We import the EdgeHD 9.25 directly, supply it with a GST invoice, and can match it with the right mount, camera and observatory dome.

Key features

• 235mm (9.25") aperture – gathers 1,127× more light than the human eye; limiting magnitude 14.4
• EdgeHD aplanatic optics – coma-free, flat focal plane for sharp stars across large sensors and wide-field eyepieces
• Multiple focal ratios – native f/10, f/7 with the optional 0.7x reducer, or ~f/2 via Fastar with a third-party lens
• 0.49 arcsecond resolution (Dawes) – fine planetary, lunar and double-star detail
• Portable at 9.53 kg – easy to carry and mount for field imaging or star parties
• StarBright XLT coatings – up to 97.4% transmission on the Schmidt corrector
• Mirror clutches – lock the primary mirror against image shift during long exposures
• Rear-cell cooling vents – 50-mesh filtered vents release warm air and keep dust out
• CGE dovetail bar – fits Celestron CGX, CGEM II and other mounts with CGE-style saddles
• Accessories included – 23mm Luminos 2" eyepiece (102×), 2" mirror diagonal, 9x50 finderscope

EdgeHD optics: why a flat field matters

A standard Schmidt-Cassegrain only focuses stars sharply on a curved surface. Camera sensors are flat, so edge stars turn into comet shapes or soft blobs.

EdgeHD adds a corrector lens assembly in the baffle tube. This makes the telescope aplanatic – free of spherical aberration and coma – and flattens the focal plane. Celestron rates the EdgeHD field as more than three times flatter than a standard SCT.

What this means in practice:

• Round, sharp stars to the corners of DSLR, mirrorless and dedicated astronomy cameras
• Better effective resolution and limiting magnitude than a standard SCT of the same aperture
• No separate field flattener needed in the imaging train
• Crisper views at the edge of wide-angle 2" eyepieces

The EdgeHD 9.25 changes role depending on what you attach.

A Barlow lens on the native f/10 setup adds image scale for high-resolution lunar, planetary and solar imaging (with a certified solar filter).

Built for long-exposure imaging

The EdgeHD tube is mechanically redesigned for astrophotography, not just visual use.

• Mirror clutches: Flexible tension clutches hold the primary mirror after focusing without stressing it, keeping the target centred through long imaging sessions.
• Cooling vents: Rear-cell vents release warm air trapped behind the primary mirror, so the optics reach ambient temperature faster. Each vent has a 50-mesh dust filter.
• StarBright XLT coatings: Applied to every optical surface for maximum light throughput across the visual and photographic spectrum.
• Aluminium tube: Lightweight and rigid, ideal for both permanent piers and portable setups.
• Factory acceptance test: Every EdgeHD is checked for optical surface quality, then imaged on an artificial star with a camera before shipping.

Technical specifications

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

In the box and recommended add-ons

What's in the box: EdgeHD 9.25" optical tube with CGE dovetail bar, 23mm Luminos 2" eyepiece, 2" mirror star diagonal with 1.25" adapter, 9x50 finderscope.

At 9.53 kg, the tube suits mid-weight equatorial mounts. Leave payload headroom for cameras, guiders and dew control when imaging.

Who the EdgeHD 9.25 is for

• Schools, colleges and science centres setting up an astronomy lab or rooftop observatory
• Serious amateurs moving up from an 8" SCT who want more aperture without a heavy mount
• Planetary imagers chasing high-resolution views of Jupiter, Saturn, Mars and the Moon
• Deep-sky astrophotographers who need a flat field and the option of f/7 or f/2 imaging

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

Frequently asked questions

What is the price of the Celestron EdgeHD 9.25 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.

EdgeHD 9.25 vs EdgeHD 8 – which should I buy? The 9.25" gives 235mm aperture against 203mm, about a third more light, and finer resolution. It weighs only a little more, so it is the popular step up for imagers who want more reach on the same class of mount.

EdgeHD 9.25 vs EdgeHD 11 – what's the difference? The 11" has more aperture and a longer focal length but needs a heavier mount. The 9.25" is easier to transport and set up, and is a strong choice for planetary imaging.

What is the difference between EdgeHD 9.25 and a standard C9.25? Both share a 235mm aperture, but EdgeHD adds a corrector that removes coma and flattens the field. Stars stay sharp to the edge of large camera sensors.

Does the EdgeHD 9.25 come with a mount? No. This is the optical tube assembly with a CGE dovetail. Pair it with a mount such as the Celestron CGX or CGEM II, or a Paramount or PlaneWave mount for observatories.

Can I use it for visual observing? Yes. The included 23mm Luminos 2" eyepiece gives 102×, and the useful range is 34× to 555×.

What reducer works with the EdgeHD 9.25? The Celestron 0.7x Reducer Lens for EdgeHD 925 brings it to f/7 at about 1645mm focal length.

Is the EdgeHD 9.25 Fastar / HyperStar compatible? Yes. The secondary mirror can be replaced with a third-party Fastar-compatible lens for ultra-fast imaging near f/2.

How much does the EdgeHD 9.25 weigh? The optical tube weighs 9.53 kg (21 lbs). It is 559mm long and 271.78mm in diameter.