Celestron 8" EdgeHD optical tube, CGE/Losmandy dovetail


Availability: In stock

The EdgeHD high definition flat field optics of this Celestron 8" EdgeHD optical tube make true astrographic-quality 8" optics truly affordable . . .
Our Product #: C8HDOTA
Celestron Product #: 91030-XLT
Recommended Accessories

Product Description

This Celestron EdgeHD 8 optical tube has:
• 8" EdgeHD Faster-compatible high definition aplanatic Schmidt-Cassegrain optics
• StarBright XLT optical multicoatings for the highest possible light transmission
• mirror locks and cooling vents
• 9 x 50mm finderscope in quick-release bracket
• 1.25" star diagonal
• 40mm 1.25" Plössl eyepiece (51x)
• CGE (Losmandy-style "D-plate") dovetail
• 2-year warranty

The compact and easily transportable Celestron 8" EdgeHD optical tube has new and unique 8" aperture aplanatic (free from coma and corrected for spherical aberration) EdgeHD high definition/high contrast Schmidt optics. The advanced EdgeHD optical system uses a dedicated dual-element field flattener lens made from premium Schott optical glass in its central baffle tube to reduce off-axis coma and produce aberration-free images across a wide 42mm image circle (as large as the diagonal of a 35mm negative or large format CCD chip and ideal for astrophotography).

In addition to reduced off-axis coma, the EdgeHD optics deliver an astrograph-quality focal plane more than three times flatter than standard Schmidt-Cassegrains and dramatically flatter than competing coma-free designs. Stars are smaller and more concentrated, creating brighter images and allowing you to see down to a fainter magnitude than other equally-sized telescopes. With EdgeHD optics, you see sharp point-like stars to the very edges of some of the largest CCD and DSLR chips available today.

For the ultimate in brightness and contrast, the 8" EdgeHD optical tube has state-of-the-art Starbright XLT multicoatings. Its light grasp is almost 850 times that of even the sharpest dark-adapted eye, revealing to your eye and camera star clusters, nebulas, planets, and galaxies in amazing detail. The Fastar-compatible optical tube even allows imaging down to an incredibly-fast f/2 focal ratio using optional accessories.

This Celestron Optical Tube's Optics . . .

EdgeHD aplanatic Schmidt-Cassegrain optics: 8" aperture (2032mm focal length f/10). Guaranteed diffraction-limited optical performance, free from coma and corrected for spherical aberrations (aplanatic design). Dual-element field flattener lens built into central baffle tube. The 17" long aluminum optical tube has a large handle on the rear cell and weighs only 14 pounds, making it easy to transport and assemble the optical tube to a mount in the field. For more details, click on the "EdgeHD optics" link in the support tab above.

Starbright XLT fully multicoated optics: This high transmission/high reflectivity optical coatings package applied to each optical surface gives you visibly higher light transmission for brighter deep space images and shorter exposure times during imaging. It also increases the contrast on subtle lunar, planetary, and nebula details when compared with optics using ordinary coatings or multicoatings. For more details, click on the "Starbright XLT" link in the support tab above.

Fastar compatible: For the ultimate in wide-field catadioptric imaging, the EdgeHD optical tube is Fastar compatible to allow CCD imaging at a blazingly-fast f/2 focal ratio. For f/2 imaging, an optional Fastar lens assembly lens replaces the scope's removable secondary mirror (an exchange that takes only a few minutes). Your CCD camera is attached to the Fastar lens. This puts your camera at the f/2 position in the center of the Schmidt corrector lens at the front of the optical tube, rather than in its normal f/10 position at the Cassegrain focus at the rear. The Fastar option is for imaging only and cannot be used for visual observing.

This Celestron Optical Tube's Mechanics . . .

Focusing: Focusing is accomplished by turning a knob on the rear cell that moves the primary mirror fore and aft along the central baffle tube to adjust the focus. The Celestron focusing mechanism is supported by two pre-loaded ball bearings, minimizing the "mirror flop" typical of bushing-type focus mechanisms that causes image shift during critical focusing.

Mirror locks: Flexible tension locks hold the mirror in place after correct focus is achieved for imaging and reduce image shift when rotating the tube around a mount (when moving past the zenith during astrophotography, for example). Unlike other designs that have only one locking knob located off to one side of the mirror, the Celestron system uses three locks equally spaced around the mirror to distribute the mirror locking force symmetrically.

The focuser itself acts as one of the locks, while two flexible rods spaced 120° away in either direction act as the second and third locks. Controlled by variable tension knobs on the rear cell, these rods act in conjunction with the focuser to hold the mirror in place without putting any asymmetrical force or pressure on the mirror. This keeps the image centered in the eyepiece (or chip) no matter what the orientation of the optical tube.

Tube vents: Two cooling vents on the rear cell allow warm air to be released from behind the primary mirror when the scope is taken out for a night's observing or imaging. This shortens the amount of time needed for the optics to cool down to ambient air temperature for peak performance. Each vent has an integrated 60 micron micro-mesh filter guaranteed to let warm air out without letting dust in.

Dovetail rail: The full length dovetail rail mounted under the optical tube fits Celestron CGEM, CGE, and CGE Pro mounts, as well as any other make or model German equatorial mount that uses a Losmandy-style "D-plate" mounting dovetail slot.

This Celestron Optical Tube's Supplied Accessories . . .

Finderscope: The supplied 9 x 50mm straight-through achromatic design finderscope has a wide 5.8 degree field of view. It is mounted in a spring-loaded easy-adjust quick release bracket.

Star diagonal: The supplied star diagonal is a 1.25" prism type. Also included is a 1.25" visual back.

Eyepiece: The standard equipment eyepiece is a 1.25" 40mm Plössl (51x). The eyepiece field of view is 0.84 degrees, almost 70% larger than the full Moon.

Two-year warranty: All Celestron optical tubes have a two-year warranty.

Tech Details

Aperture 8"
Focal Length 2032mm
Focal Ratio f/10
Highest Useful Magnification 405x
Weight 14 lbs.
Resolution 0.57 arc seconds
Visual Limiting Magnitude 14
Warranty 2 years


Review by:
This was my first big telescope and it is fun and has lasted about 2 years now. Necessary to have a good mount though and I could watch the stars all night. Just getting into DSLR photography with it and it is meeting expectations so far. (Posted on 10/6/2019)
Review by:
One scope and a couple of accessories fits all of my viewing and imaging needs. Native F/10 at 2032mm F/L works great for planetary viewing and imaging with great detail. Add a focal reducer and get some faint fuzzy objects in the eyepiece or on the sensor. Want to image REALLY big things like the Leo Triplet, the Andromeda Galaxy or the Orion Nebula region? Slap a Hyperstar on the front and image at F/2 with huge light grasp and fine detail. One piece of glass that does it all very well. (Posted on 9/23/2019)
Review by:
The C8 Edge HD is one of the most versatile instruments around both for visual and for imaging. I use mine dedicated to all forms of imaging and for visual. Lovely bright views with enough aperture to show DSO nicely and enough to resolve detail on the solar system subjects. The ability to transform this instrument into an F2, F7 or F10 system is what makes it the most versatile. I do not use the F2 option, but I do use the F7 and F10 options. At F7 it's excellent for galaxy and smaller DSO imaging. At F10 I use it for solar system imaging. I even use this for solar imaging and it performs very well with appropriate thermal handling installed. The C8 Edge lives in my observatory and is mounted and ready to go at all times because it's as close to a "do all" instrument as you can get that has a flat field involved. Highly recommended! (Posted on 8/3/2019)
Review by:
I have an 8-inch EdgeHD. It has been wonderful with the views of the planets and the moon. It has worked very well with the Powermate series by TeleVue for improving the image resolution for lucky imaging. I love my EdgeHD and look forward to its continued use in DSO imaging as well. (Posted on 7/26/2019)
Review by:
I have used the HD8 for over two years with only minor issues with the high-torque mirror locks and the critical short back focus. I image at both f/10 and f/7, images are equally flat from edge-to-edge on a 22 mm chip. Focusing is very smooth and the tube weight of around 14 lbs is manageable for my 84 years. (Posted on 7/22/2019)
Review by:
The EdgeHD scopes are simply wonderful. I have the EdgeHD8. At F10, the field is completely flat and the color rendition is true and without artifacts. In addition, it covers the full field of view when using a 36mm full frame camera. The scope is light weight relative and is, IMO, the most versatile optic on the market. You can take it to F7 with the Celestron reducer and even to F2 with the Starizona Hyperstar. I have used all three combinations with my EdgeHD8 and converting between one or the other is a painless effort. If you want a hassle free, completely flat optic with true colors, then I highly recommend the Edge scopes. (Posted on 12/31/2018)
Review by:
I have used for several years as my main scope for both viewing and some photography. This scope has always exceeded my expectations. I did add a right angle finder to make it much easier to use. I would highly recommend for anyone needing this size scope for either price or portability. (Posted on 10/24/2018)
Review by:
I have used this scope now for 2 years under all conditions and night skies. I have used for some planetary photography as well. It has always exceeded my expectations, giving clear high contrast views of both planets and deep sky objects. Would recommend for anyone needing a high quality portable scope. I did add the right angle finder to make it much more comfortable to use. (Posted on 10/24/2018)
Review by:
I bought one of these from Astronomics years ago and it has served me well. Both for planetary observing and for astrophtography / viseo astronomy it has been great. Nice balance of size/weight versus aperture. One thing you should definitely get with it is a 2" visual back - don't know why Celestron is still shipping these with 1.25" visual backs when all premium eyepieces at long focal lengths (which you need with this scope) are 2" format. (Posted on 10/6/2018)
Review by:
Absolutely love this scope. I've owned many c8's in the past and this is by far the best sample I have ever owned. The views both on an off axis are excellent, and those widefield 82 deg ep's are such a joy in this scope! (Posted on 8/4/2017)
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Supplied Accessories

  • Starbright XLT fully multicoated 8" f/10 Fastar-compatible EdgeHD optics
  • 9 x 50mm finderscope
  • 1.25" star diagonal with 1.25" visual back
  • 1.25" 40mm Plössl eyepiece (51x)
  • Dust covers
  • CGE (Losmandy-style "D-plate") dovetail mounting rail.