Celestron EdgeHD 8" Optical Tube Assembly (CGE Dovetail) – 91030-XLT

The Celestron EdgeHD 8" Optical Tube Assembly (model 91030-XLT) is the most compact and affordable way into Celestron's flagship EdgeHD optics. Its 203mm aperture and 2032mm focal length fit in a 432mm tube weighing only 6.35 kg.

EdgeHD corrects both coma and field curvature, so stars stay pinpoint to the edge of large camera sensors. At this weight, the EdgeHD 8 rides comfortably on mid-range equatorial mounts, which keeps the total cost of a serious imaging setup within reach.

Modern Telescopes is an authorized Celestron distributor in India. We import the EdgeHD 8 directly, supply it with a GST invoice, and can pair it with the right mount, camera and accessories.

Key features

• 203mm (8") aperture – gathers 843× more light than the human eye; limiting magnitude 14
• EdgeHD aplanatic optics – coma-free, flat focal plane for sharp stars across large sensors and wide-field eyepieces
• Three focal ratios – native f/10, f/7 with the optional 0.7x reducer, or ~f/2 via Fastar with a third-party lens
• 0.57 arcsecond resolution (Dawes) – crisp lunar, planetary and double-star detail
• Lightweight at 6.35 kg – the most portable EdgeHD, ideal for field imaging and outreach
• 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 CGEM II, CGX and other mounts with CGE / Losmandy-style saddles
• Accessories included – 40mm Plössl 1.25" eyepiece (51×), 1.25" star 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 stars near the frame edges blur into comet shapes.

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 8" SCT
• No separate field flattener needed in the imaging train
• Sharper views at the edge of wide-field eyepieces

One telescope, three imaging systems

Celestron designs the EdgeHD 8 to work at three focal ratios.

A Barlow lens on the native f/10 setup adds magnification 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 sessions.
• Cooling vents: Rear-cell vents release warm air trapped behind the primary mirror so the optics cool faster. Each vent has a 50-mesh dust filter.
• StarBright XLT coatings: Applied to every optical surface for maximum light throughput.
• Aluminium tube: Light and rigid, easy to carry to dark-sky sites.
• 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 8" optical tube with CGE dovetail bar, 40mm Plössl 1.25" eyepiece, 1.25" star diagonal, 9x50 finderscope.

At 6.35 kg, the tube suits mid-range equatorial mounts. Leave payload headroom for cameras, guiders and dew control when imaging.

Who the EdgeHD 8 is for

• First serious astrophotography setup – EdgeHD optics on a mount most imagers can afford
• Schools and science centres needing a light, easy-to-handle telescope for labs and outreach
• Travelling observers who image from dark-sky sites away from city lights
• Planetary and lunar imagers wanting sharp optics in a compact tube

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 EdgeHD 8 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.

What is the difference between EdgeHD 8 and a standard Celestron C8? Both have a 203mm aperture, but EdgeHD adds a corrector that removes coma and flattens the field. Stars stay sharp to the edge of large camera sensors, which a standard C8 cannot match.

EdgeHD 8 vs EdgeHD 9.25 – which should I buy? The EdgeHD 8 is lighter (6.35 kg vs 9.53 kg) and runs on smaller mounts, keeping system cost down. The 9.25" adds aperture (235mm) and finer resolution if your mount can carry it.

Does the EdgeHD 8 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.

Can I use it for visual observing? Yes. The included 40mm Plössl gives 51×, and the useful range is 29× to 480×.

What reducer works with the EdgeHD 8? The Celestron 0.7x Reducer Lens for EdgeHD 800 brings it to f/7 at about 1422mm focal length.

Is the EdgeHD 8 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 8 weigh? The optical tube weighs 6.35 kg (14 lbs). It is 432mm long and 238mm in diameter.