Celestron EdgeHD 11″ Optical Tube Assembly

The Celestron EdgeHD 11″ Optical Tube Assembly combines the impressive light-gathering capability of an 11-inch Schmidt-Cassegrain with Celestron’s advanced EdgeHD optical system, creating a telescope equally at home in a visual observatory or as the centrepiece of a serious astrophotography setup. While retaining the compact dimensions that have made Schmidt-Cassegrain telescopes popular for decades, the EdgeHD introduces additional corrective optics that significantly improve image quality across the entire field of view.

Unlike a conventional Schmidt-Cassegrain telescope, the EdgeHD employs a Schmidt corrector plate together with a dedicated internal field-correcting lens group housed within the central baffle tube. This aplanatic optical design corrects both field curvature and off-axis coma, producing sharp, round stars across the imaging field rather than only at the centre. The result is a telescope capable of taking full advantage of modern large-format astronomy cameras while also delivering beautifully sharp views through wide-angle eyepieces.

With a generous 279.4mm aperture, the EdgeHD 11″ gathers approximately 42% more light than the EdgeHD 9.25″, revealing fainter galaxies, finer nebular structure and more subtle planetary detail. The increased aperture also improves resolving power, allowing experienced observers to take advantage of excellent seeing conditions for high-magnification lunar, planetary and double-star observing.

At its native 2800mm focal length and f/10 focal ratio, the telescope provides the image scale needed for smaller deep-sky objects and high-resolution planetary imaging. For astrophotographers seeking a wider field of view and shorter exposure times, the dedicated EdgeHD 0.7× focal reducer transforms the system into a 1960mm f/7 astrograph while preserving the telescope’s corrected flat-field performance. The removable secondary mirror also makes the telescope compatible with third-party HyperStar systems, enabling ultra-fast imaging at approximately f/2 for large nebulae and wide-field deep-sky targets.

The EdgeHD 11″ incorporates several mechanical refinements designed specifically with imaging in mind. Rear-cell ventilation ports fitted with integrated 50-mesh filters accelerate thermal equalisation by allowing warm air to escape while helping prevent dust entering the optical tube. Flexible mirror support clutches reduce mirror movement during long-exposure imaging, improving image stability and helping maintain critical focus throughout the night.

Celestron’s premium StarBright XLT optical coatings maximise light transmission throughout the optical system, enhancing image brightness and contrast for both visual observation and astrophotography. Every EdgeHD optical tube also undergoes individual optical testing before leaving the factory to verify that it meets Celestron’s imaging performance standards.

Despite its substantial aperture, the aluminium optical tube remains remarkably compact for its capability and is supplied with a CGE (Losmandy-style) dovetail bar for secure mounting on suitably capable equatorial mounts. This combination of portability, optical excellence and imaging versatility has made the EdgeHD 11″ one of the most respected premium Schmidt-Cassegrain telescopes available.