See the Universe in HD EdgeHD 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.
True Astrograph 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. Learn more about EdgeHD technology.
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.
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 our rigid quality assurance. This final acceptance test confirms the EdgeHD will perform in the field and deliver high-quality astroimages.
Optical Design
EdgeHD
Aperture (mm)
234.95 mm (9.25 in)
Focal Length
2350 mm (93 in)
Formula:Focal Ratio
10
Focal Length of Eyepiece 1 (mm)
23 mm (0.91 in)
Formula:Magnification of Eyepiece 1
102 x
Finderscope
9x50
Star Diagonal
2" w/ 1.25" adapter
Optical Tube
Aluminum
Formula:Highest Useful Magnification
555 x
Formula:Lowest Useful Magnification
34 x
Formula:Limiting Stellar Magnitude
14.4
Formula:Resolution (Rayleigh)
0.59 arc seconds
Formula:Resolution (Dawes)
0.49 arc seconds
Formula:Light Gathering Power (Compared to human eye)
1127 x
Secondary Mirror Obstruction
3.35 in (85 mm)
Formula:Secondary Mirror Obstruction by Diameter
36%
Formula:Secondary Mirror Obstruction by Area
13%
Optical Coatings
StarBright XLT
Optical Tube Length
22 in (559 mm)
Optical Tube Weight
21 lbs (9.53 kg)
Dovetail Compatibility
CGE Mount