The Celestron EdgeHD 8" SC tube 8-inch (203 mm) Schmidt-Cassegrain telescope is based on the earlier C8 series, but thanks to the built-in two-element corrector, it is free of the coma defects and curved image planes typical of the model, so it images stars point-like to the edge of the field of view. The compact size of the Celestron EdgeHD 8" SC is a true all-rounder, hiding behind its compact size is a very powerful performance and excellent optics. The telescope is ideal for both visual and photographic purposes.
Celestron EdgeHD telescopes are Fastar-compatible, meaning that, like "conventional" SC tubes, the auxiliary mirror can be removed and, with the right adapter, a CCD camera can be mounted directly in place, in which case the instrument operates as an extra bright F2 system. Of course, common SC accessories can also be easily fitted to the tube. Filtered vents on the telescope tube help to accelerate heat dissipation. The annoying feature of catadioptric binoculars, image-shift, has been minimised by a more mechanically stable focusing system. Special mention should also be made of the practical, robust handle on the tube.
The optical surfaces of the EdgeHD telescopes are coated with the company's proprietary StarBright XLT coating which increases the light-harvesting capability of the telescopes. When in use, the transmission of the corrective lens reaches 98%, while the reflectance of the main and auxiliary mirrors reaches 95%. In addition, the contrast of the image is increased. The basic package also includes a zenith mirror, a 9x50 finder scope and a 40 mm Plössl eyepiece.
Celestron tubes are hand-figured and hand-matched, which means that they consistently outperform the optical quality of competing SC tubes in various tests.
