Celestron Schmidt-Cassegrain telescope SC 279/2800 EdgeHD 1100 OTA (16402)

The Celestron EdgeHD telescope is an advanced aplanatic Schmidt-Cassegrain design that provides distortion-free, sharp images across the entire visual and photographic field of view. Unlike standard Schmidt-Cassegrain telescopes, the EdgeHD corrects both off-axis star coma and field curvature, making it a true astrograph. This ensures pinpoint stars and a flat focal plane, ideal for modern imaging sensors.

Many optical systems marketed as "astrographs" produce sharp stars only across a curved focal plane. While suitable for visual use, this curvature causes stars at the edges to appear out of focus when using flat imaging sensors. EdgeHD optics provide a focal plane that is more than three times flatter than standard Schmidt-Cassegrains and significantly flatter than competing coma-free designs. This guarantees visibly sharp stars across even the largest CCD sensors.

The EdgeHD also enhances resolution and limiting magnitude compared to telescopes of similar aperture. Its StarBright XLT coatings maximize light throughput, improving performance for both visual observation and astrophotography.

Enhanced Mechanical Features

• Mirror Clamps: Flexible tension clutches hold the primary mirror securely in place without applying pressure, reducing image shift during long exposures. This ensures stable imaging with targets remaining centered.

• Tube Vents: Cooling vents on the rear cell allow hot air to escape from behind the primary mirror. Each vent includes an integrated micromesh filter to release warm air while preventing dust entry.

• Fastar Compatibility: The EdgeHD supports multiple focal ratios for added versatility. At its native f/10, it provides excellent image scale for small deep-sky objects. With an optional reducer lens, the focal ratio can be reduced to f/7 for a wider field of view without sacrificing performance. Additionally, all EdgeHD OTAs are Fastar-compatible, allowing the secondary mirror to be replaced with third-party accessories for ultra-fast f/2 wide-field imaging.

Precision Design and Rigorous Testing
EdgeHD telescopes feature precision-machined mechanics and a spherical secondary mirror for easy collimation. Each unit undergoes rigorous quality assurance testing, including imaging with a camera and artificial star, to ensure optimal performance in real-world conditions.

Included with the Telescope:

• Optical Tube Assembly (OTA) with 279mm aperture and 2800mm focal length

• Axiom LX 23mm eyepiece (2")

• 2" star diagonal (90°) with 1.25" adapter

• Mounting rail (Losmandy-style prism rail)

• 9x50 straight-view finder scope

Specifications

Optics:

• Type: Reflector (EdgeHD Schmidt-Cassegrain)

• Aperture: 279mm

• Focal Length: 2800mm (f/10)

• Resolving Capacity: 0.41 arcseconds

• Light Gathering Power: 1589x compared to the human eye

• Maximum Useful Magnification: 558x

• Tube Construction: Full tube; Weight: 12.7kg

Focuser:

• Type: SC thread with 2" eyepiece connection

Mount:

• Type: OTA only (no mount included)

Included Accessories:

• Eyepiece (2"): Axiom LX 23mm eyepiece

• Finder Scope: 9x50 straight-view finder scope

• Diagonal Mirror: 2", 90° star diagonal with 1.25" adapter

• Mounting Rail: Losmandy-style prism rail

General Information:

• Series: OTA

• Total Weight: 12.7kg

Recommended Use

The EdgeHD telescope is designed for advanced users and observatories due to its premium optics and compatibility with astrophotography equipment but is not recommended for beginners. It excels in lunar/planetary observation, deep-sky exploration of nebulae and galaxies, and high-quality astrophotography but is not suitable for solar observation unless used with an appropriate solar filter.