The CGEM EdgeHD Series combines Celestron's newly designed CGEM Computerized Equatorial mount with its new EdgeHD optical system. With up to 11" of aperture, our premium StarBright XLT coatings and diffraction limited performance, CGEM EdgeHD Series are designed as premier astro-imaging telescopes.

New Optical Design
The EdgeHD optical system takes all of the compact power popularized by the SCT and combines it with an improved high definition optical system for wide field, astrograph quality images.

As a visual instrument  EdgeHD optics deliver pinpoint images even with your widest field eyepiece.    You can search for all of the Messier Catalog objects and see hundreds of other equally interesting NGC, IC and Caldwell objects with amazing clarity. For astroimaging, the EdgeHD optics produce aberration-free images across your favorite CCD or DSLR camera. All EdgeHD optics are designed to produce an extremely flat focal plane precise enough to match the strict tolerances of the largest commercial ccd detectors, allowing all stars to be in tight focus to the very edge of the chip.

Diffraction Limited
Some companies boast that their telescopes give diffraction limited stars in the very center of the field of view .  EdgeHD optics not only produce diffraction limited stars on axis, but maintain diffraction limited stars across the entire field of view of many of the most popular astrophotography cameras. Even at the very edge of a full frame camera chip, the EdgeHD delivers diffraction limited stars of only 1 arc seconds.
The EdgeHD optics produce a focal plane more than 3 times flatter than the standard equivalent SCT telescope with diffraction limited stars across the entire Nikon D3 or Canon 5D field of view!

Along with the newly designed optics, the EdgeHD also has re-designed mechanics guaranteed to help you get the maximum performance from your instrument. Features include:

Mirror Locks – To hold the mirror in place and reduce image shift during imaging.

Tube Vents - Each vent has an integrated 60 micron micro-mesh filter allowing hot air to be released from behind the primary mirror.

Fastar Versatility – All EdgeHD optical tubes are equipped with a removable secondary mirror for fast f/2 ccd imaging. Not only does imaging in the FASTAR configuration allow for exposure times that are 25 times faster than at f/10, but also yields a field of view five times wider. A perfect combination for imaging your favorite wide field objects in a fraction of the time. (FASTAR imaging requires a third party lens assembly in place of the secondary mirror).

Axiom Eyepiece - CGEM 925 HD & 1100 HD models come with Celestron's top of the line Axiom eyepiece. With a 23mm focal length and 82° AFOV you get an incredible combination of power and wide field of view. Plus each Axiom eyepiece is optimized to deliver pinpoint images when used with a flat field telescope.

CGEM™ Mount

The CGEM™ mount has a fresh, attractive, bold appearance and is capable of carrying Celestron’s higher-end SCT optical tubes (up to 11") securely and vibration free which is ideal for both imaging and visual observing.

Ergonomic Design - CGEM was designed to be ergonomically friendly with large Altitude and Azimuth adjustment knobs for quick and easy polar alignment adjustment.  The internal RA and DEC motor wiring provides a clean look and an easy and trouble free set up.

Innovation - The CGEM series has a new innovative Polar alignment procedure called All-Star™ (patent pending). All-Star allows users to choose any bright star, while the software calculates and assists with polar alignment.  Another great feature of the CGEM, sure to please astroimagers, is the Permanent Periodic Error Correction (PEC) which allows users to train out the worm gears periodic errors, while the mount retains the PEC recordings.

Performance - For objects near the Meridian (imaginary line passing from North to South), the CGEM will track well past the Meridian for uninterrupted imaging through the most ideal part of the sky. The CGEM mount has a robust database with over 40,000 objects, 100 user defined programmable objects and enhanced information on over 200 objects.

Celestron's CGEM mount is the perfect fit between the Advanced Series and CGE Series.  Offering the portability of the Advanced Series and the precision of the CGE.

See the Universe in HD

EdgeHD is an aplanatic Schmidt telescope designed to produce aberration-free images across a wide visual and photographic field of view. The optical system was designed to reduce more than just off-axis star coma, but also to give an astrograph quality flat focal plane all the way to the edge of the field of view.

True Astrograph Quality

Many optical designs that advertise themselves as "astrograph" quality actually only produce pinpoint stars across a curved focal plane. While this may be acceptable for visual observing, stars will appear out of focus at the edge when used with a flat chip sensor of a digital camera.  EdgeHD optics produce a focal plane more than three-times flatter than a standard Schmidt Cassegrain telescope and dramatically flatter than other competing coma-free designs. This guarantees you visibly sharp stars across some of the largest ccd chips available today.

Above: A curved focal plane does not perfectly coincide with a flat CCD chip and therefore will appear out of focus at the edges.

Even when focused sharply in the center of the field of view, a curved focal plane will produce out of focus stars at the edges. The wider the field of view the more pronounced the defect becomes. Compare the two images below. Both images were taken with the same camera under the same conditions. When focused on-axis both appear to be sharp in the center of the image. But as you view the stars closer and closer to the edge, the stars in the first image (taken with a competing coma-free design) become larger and less focused until finally, at the very corners, the star images are de-focused so much that they appear as rings instead of pinpoints.

Competing Coma Free Optical Design

Celestron EdgeHD Optics

Fig 1 - Competing Coma Free design focused on axis, shows sharp stars in the center of the image, but dramatically out of focus stars (donuts) at the edges.
Fig 2 - EdgeHD focused on axis, focuses sharply across the entire FOV.
Both M3 images taken with a 35 mm chip (42 mm diameter focal plane) camera

Improved Performance

Superior edge performance not only creates rounder, more pleasing stars but actually improves the resolution and limiting magnitude when compared to telescopes of equal aperture.

Celestron's High Definition optics let you resolve smaller spot sizes all the way to outer edge, revealing finer detail and greater contrast.

Brighter Images

EdgeHD optics give you smaller (more concentrated) stars that create brighter images and allow you to see down to a fainter magnitude than other equally sized telescopes. Poor edge quality can spread out starlight so much that the brightness of a star appears the same as the sky background, making it undetectable to your eye (or camera). With EdgeHD optics you will be able to capture the faintest of galaxies all the way to the corner of your full frame camera chip.

XLT Coating

Coupled with Celestron's XLT coating group on every surface, EdgeHD optics give you maximum light throughput across the widest visual and photographic spectrum.

Mechanical Features

In addition to Celestron's new optimized optical design, the EdgeHD tube has been redesigned to make sure you get the most from your optics each and every night.

Mirror Support - Flexible tension clutches hold the mirror in place and reduce image shift when rotating the tube around the mount. The flexible rods allow the mirror to be held in place without putting any force or pressure on the mirror assembly, keeping the image centered in the eyepiece (or chip).

Tube Vents - Cooling vents located on the rear cell allow hot air to be released from behind the primary mirror. Each vent has an integrated 60 micron micro-mesh filter guaranteed to let warm air out without letting dust in.

Fastar Versatility -The EdgeHD are the most versatile imaging scopes available today. At its native f10 you can achieve the image scale neccesary to capture the smallest of deep sky objects. With the optional reducer lens (coming soon) you can increase your field of view without sacrificing optical performance. A barlow gives you the added power for high resolution planetary, lunar and solar imaging. And of course all EdgeHD optical tubes are Fastar compatible for ultra fast f/2 wide field imaging*. Each tube has been fitted with a removable secondary mirror and are opto-mechanically aligned on a laser bench to ensure they are axially symmetric in any configuration.

*requires the use of the Hyperstar lens assembly

Easy Collimation - With precision machined mechanics and a spherical secondary mirror, EdgeHD optics can be collimated accurately and easily to guarantee that they perform to their potential every time you use them.