Celestron Advanced VX 9.25" EdgeHD SC telescope

New optical design
The Celestron EdgeHD 9.25" SC telescope combines the compact design of Schmidt-Cassegrain telescopes with significantly improved image quality at the edge of the field of view. This optical system not only offers astrograph-like performance, but also delivers completely distortion-free, sharp images all the way to the edge of both the visual and photographic field of view. It corrects not only off-axis coma—as other so-called “coma-free” optical systems on the market do—but also field curvature!

The difference
Many optical systems are marketed as “astrographs”; however, they produce the desired pinpoint star images along a curved focal plane. When imaging with modern CCD cameras, this results in noticeable field curvature that increases towards the edge of the field, becoming more pronounced with larger CCD sensors. While the stars remain round, they are slightly out of focus.

Celestron EdgeHD telescopes correct not only coma but also this curvature all the way to the edge of the field of view, ensuring that images captured even with large CCD sensors remain perfectly sharp and evenly focused across the entire sensor, right into the corners.

The new optical system improves resolution compared to competing optical systems with similar apertures. EdgeHD optics also feature Celestron XLT multilayered coatings, providing significantly better performance than comparable systems available on the market.

Celestron EdgeHD telescopes are Fastar-compatible, meaning that—similarly to “conventional” SC optical tubes—the secondary mirror can be removed and a CCD camera can be fitted directly in its place using a suitable adapter. In this configuration, the instrument operates as an extra-fast f/2 focal ratio system. Naturally, commonly used SC accessories can also be easily fitted to the optical tube. Filtered ventilation openings on the telescope tube promote faster thermal equalization. The annoying characteristic of catadioptric telescopes, mirror shift during changes in direction, has been minimized by means of a mechanically more stable focusing system. The practical, sturdy handle on the optical tube also deserves special mention.

The Celestron Advanced VX mount is a highly portable mount optimized for astrophotography. For further information, please visit the product page.