Celestron CGEM II 11-Inch EdgeHD Schmidt-Cassegrain Telescope

Celestron EdgeHD 11" SCT Optical Tube Assembly

The night sky has always fascinated individuals and with good reason. The heavens are teeming with life, but sadly, most of it is not visible to the naked eye. Now with the study of Astronomy and the invention of telescopes, the moon, stars and planets are all within reach. With the right instruments, there's no telling what you might see.

See the Universe in HD
The Celestron EdgeHD 11" SCT Optical Tube Assembly is an aplanatic, flat field Schmidt-Cassegrain telescope that produces aberration-free images across a wide visual and photographic field of view. The optical system was designed to reduce more than just off-axis star coma; it also provides an astrograph-quality flat focal plane all the way to the edge of the field of view. The EdgeHD OTA has an 11" aperture with a focal length of 2800 mm. It comes with a 9x50 finderscope, 2” mirror diagonal for more comfortable viewing, and wide-angle 23 mm Luminos 2" eyepiece.

True Quality
Many optical designs that advertise themselves as "astrographs" actually only produce pinpoint stars across a curved focal plane. While this may be acceptable for some visual observing, stars will appear out of focus at the edge when used with the flat chip sensor of a digital camera. EdgeHD optics produce a focal plane more than three-times flatter than a standard Schmidt-Cassegrain telescope and dramatically flatter than competing coma-free designs. This guarantees you visibly sharp stars across some of the largest CCD chips available today.

Improved Performance
Superior edge performance not only creates rounder, more pleasing stars, but actually improves the resolution and limiting magnitude when compared to telescopes of equal aperture. With Celestron’s StarBright XLT optical coatings on every surface, EdgeHD optics gives you maximum light throughput across the widest visual and photographic spectrum.

Mechanical Features
In addition to EdgeHD’s optimized optical design, the telescope tube has been redesigned to make sure you get the most from your optics each and every night. Mirror clutches, tube vents and Fastar versatility are just three examples of EdgeHD's newest features.

Flexible tension clutches hold the mirror in place and reduce image shift when taking long exposure astro-images. Once focused, the flexible rods allow the mirror to be held in place without putting any force or pressure on the mirror assembly, keeping the image centered in the eyepiece (or on the sensor).

Cooling vents located on the rear cell allow hot air to be released from behind the primary mirror. Each vent has an integrated 95-micron micromesh filter guaranteed to let warm air out without letting dust in.

EdgeHD is the most versatile imaging telescope available today. At its native f/10, you can achieve the image scale necessary to capture the smallest of deep sky objects. Add the optional reducer lens—custom-designed for your size EdgeHD tube—and you can increase your field of view without sacrificing optical performance. A Barlow gives you added power for high-resolution planetary, lunar and solar imaging. All EdgeHD optical tubes are Fastar-compatible, allowing the secondary mirror to be removed and replaced with a third party lens accessory for ultra-fast f/2 wide field imaging.

Individually Tested
Every EdgeHD that ships has been tested not only for the surface quality of each optical component, but also with a camera and artificial star to ensure the imaging system meets Celestron's rigid quality assurance. This “final acceptance test” confirms the EdgeHD will perform in the field and deliver high-quality astroimages.

Celestron Counterweight 17lbs for 19mm Shaft

Whether you are enhancing your mount setup or buying a replacement part, the counterweight is there to balance weight of the optical tube (OTA) and accessories on the other side of the Right Accession (RA Axis). If you add accessories to your telescope setup (ie camera, guider, etc), you may need to add additional counterweights to off-set the weight.

Improved Balance

If the balance is off on one-side or the other, it can do damage to your OTA and setup, the motor gear, and/or may have issues with tracking accuracy. You can add additional counterweights to improve the responsiveness to the system by reducing the mass inertia, though you need to make sure you space out the counterweights along the shaft to reduce damage to your setup and that it is cost-effective and worth it for your telescope setup.

Stable

This counterweight comes with a sturdy knurled knob locks to safely hold in place on the counterweight shaft. The counterweight is designed to fit 19mm counterweight shafts.