Celestron EdgeHD 9.25" OTA - CGE Dovetail

EdgeHD Optics: A 42mm Flat-Field Aplanatic System

The core of the EdgeHD 9.25" is its specialized optical design, which corrects for both off-axis coma and field curvature across a wide field of view. Its focal plane is more than three times flatter than a standard Schmidt-Cassegrain, an astrograph-quality flat field all the way to the edge of the 42mm field.

StarBright XLT coatings on every surface give maximum light throughput, and every EdgeHD passes a final acceptance test with a camera and an artificial star before it ships.

9.25" Aperture at f/10: Resolving 0.49 Arc Seconds

With a 234.95mm (9.25") primary mirror, this telescope gathers 1127 times more light than the human eye, and the limiting stellar magnitude is 14.4. Dawes resolution is 0.49 arc seconds and the highest useful magnification is 555x.

• Central Obstruction: The 85mm secondary mirror creates a central obstruction of 36% by diameter and 13% by area.
• Included Eyepiece: The supplied 23mm eyepiece gives 102x.

Imaging at f/10 and f/2: 146.05mm Back Focus and Fastar

At its native f/10, you get the image scale to capture the smallest deep-sky objects. The EdgeHD 925 forms its best images 146.05mm (5.75") behind the heavy-duty 3.290"x16 tpi rear thread, a generous back focus.

For wide-field targets, the OTA is Fastar-compatible. The secondary mirror can be removed and replaced with a third-party lens accessory for ultra-fast f/2 wide-field imaging.

Engineered for Imaging: Mirror Clutches and Filtered Cooling Vents

Celestron redesigned the mechanical systems of the EdgeHD tube to support long-exposure astrophotography. Flexible tension clutches hold the primary mirror in place after focusing, significantly reducing the image shift that can occur as the telescope tracks across the sky. Flexible rods hold the mirror without putting force on the mirror assembly, keeping the image centered in the eyepiece or on the sensor.

To ensure optimal image quality, cooling vents on the rear cell allow hot air to escape from behind the primary mirror. Each vent has an integrated 50-mesh filter that lets warm air out without letting dust in.

A 21 lb OTA with CGE Dovetail and 9x50 Finderscope

The aluminum optical tube assembly weighs 21 lbs (9.53 kg) and has a length of 559mm (22"), and comes on a CGE dovetail bar.

• Included Finderscope: A 9x50 optical finderscope helps you manually locate and center targets before observing or imaging.
• Included Diagonal: A 2" star diagonal with a 1.25" adapter.
• Focusing System: Focus moves the primary mirror; lock the mirror clutches once focused and loosen them before refocusing.