See the Universe in HD
The Celestron EdgeHD 8 is an aplanatic, flat field Schmidt-Cassegrain telescope that produces 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; it also provides 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 “astrographs” actually only produce pinpoint stars across a curved focal plane. While this may be acceptable for some visual observing, stars will appear out of focus at the edge when used with the 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 competing coma-free designs. This guarantees you visibly sharp stars across some of the largest CCD chips available today.
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. With StarBright XLT optical coatings on every surface, the Celestron EdgeHD 8 gives you maximum light throughput across the widest visual and photographic spectrum.
In addition to EdgeHD’s optimized optical design, the telescope tube has been redesigned to make sure you get the most from your optics each and every night.
- Mirror clutches – Flexible tension clutches hold the mirror in place and reduce image shift when taking long exposure astro-images. Once focused, 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 on the sensor).
- 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 micromesh filter guaranteed to let warm air out without letting dust in.
- Fastar versatility – EdgeHD is the most versatile imaging telescope available today. At its native f/10, you can achieve the image scale necessary to capture the smallest of deep sky objects. Add the optional reducer lens—custom-designed for your size EdgeHD tube—and you can increase your field of view without sacrificing optical performance. A Barlow gives you added power for high-resolution planetary, lunar and solar imaging. All EdgeHD optical tubes are Fastar-compatible, allowing the secondary mirror to be removed and replaced with a third party lens accessory for ultra-fast f/2 wide field imaging.
Every Celestron EdgeHD 8 that ships has been tested not only for the surface quality of each optical component, but also with a camera and artificial star to ensure the imaging system meets our rigid quality assurance. This “final acceptance test” confirms the Celestron EdgeHD 8 will perform in the field and deliver high-quality astroimages.
Celestron EdgeHD 8 Whitepaper
Want the full story behind EdgeHD optics? Celestron’s Product Development team has released a whitepaper outlining the development of EdgeHD, the manufacturing and QA process, and how to get the most out of your system. It also includes cross-sections of the EdgeHD series, comparative spot diagrams for the EdgeHD and competing “coma-free” Schmidt-Cassegrain designs, a table with specifications for visual and imaging, and graphics showing how to place sensors at the optimum back-focus distance for astroimaging.
|Aperture (mm)||203.2 mm (8 in)|
|Focal Length||2032 mm|
|Focal Length of Eyepiece 1 (mm)||40 mm|
|Magnification of Eyepiece 1||51 x|
|Highest Useful Magnification||480 x|
|Lowest Useful Magnification||29 x|
|Limiting Stellar Magnitude||14|
|Resolution (Rayleigh)||0.69 arc seconds|
|Resolution (Dawes)||0.57 arc seconds|
|Light Gathering Power (Compared to human eye)||843 x|
|Secondary Mirror Obstruction||69 mm|
|Secondary Mirror Obstruction by Diameter||34%|
|Secondary Mirror Obstruction by Area||11%|
|Optical Coatings||StarBright XLT|
|Optical Tube Length||432 mm|
|Optical Tube Weight||6.35 kg|
|Dovetail Compatibility||CGE Mount|