Celestron EdgeHD 8'' Optical Tube Assembly (CGE Dovetail)

Celestron EdgeHD 8'' Optical Tube Assembly (CGE Dovetail)

EdgeHD is a flat-field, aplanatic Schmidt-Cassegrain telescope engineered to deliver crystal-clear, distortion-free images across a wide visual and photographic field. Unlike traditional designs, this system reduces more than off-axis coma; it also provides an astrograph-quality flat focal plane that remains sharp all the way to the edge.

True Astrograph Precision

Many telescopes marketed as “astrographs” only provide pinpoint stars over a curved focal surface. While this may be acceptable for casual visual observing, it creates out-of-focus stars near the edges when paired with the flat sensors of digital cameras. EdgeHD optics produce a focal plane over three times flatter than a standard Schmidt-Cassegrain, and significantly flatter than competing coma-free optics. This ensures sharp, round stars across even the largest CCD sensors available today. (Learn more about EdgeHD technology.)

Enhanced Optical Performance

The superior edge correction not only produces more aesthetically pleasing, rounder stars but also improves both resolution and limiting magnitude when compared with similar aperture telescopes. Combined with Celestron’s StarBright XLT coatings applied to every optical surface, the EdgeHD design maximizes light transmission across the full visual and photographic spectrum.

Advanced Mechanical Features

Alongside its optimized optics, the EdgeHD tube assembly has been redesigned to provide the best performance possible, night after night.

   ➜  Mirror clutches – Flexible tension clutches secure the primary mirror, reducing image shift during long exposures. Once focus is achieved, the mirror is held firmly without stressing the assembly, ensuring the image remains centered on the eyepiece or sensor.

   ➜  Tube vents – Integrated cooling vents in the rear cell allow warm air to escape from behind the mirror. Each vent includes a 50-mesh filter that permits airflow while blocking dust.

   ➜  Fastar compatibility – EdgeHD offers unmatched versatility. At its native f/10, it captures fine detail in small deep-sky targets. With an optional, size-specific reducer lens, you can expand your field of view without compromising image quality. Add a Barlow lens for high-resolution solar, lunar, and planetary imaging. Every EdgeHD tube is also Fastar-compatible, allowing the secondary mirror to be swapped for a third-party lens assembly for ultra-fast f/2 wide-field imaging.

Individually Quality Tested

Every EdgeHD optical tube undergoes rigorous testing—not only for the surface quality of each lens and mirror, but also with a camera and artificial star to verify complete system performance. This final acceptance test ensures that each telescope meets strict quality standards and is ready to deliver outstanding astrophotography results in real-world observing conditions.