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Celestron CGEM 800

Celestron's CGEM-800 features an eight-inch Schmidt Cassegrian optical tube assembly (OTA) with XLT coatings mounted on the new CGEM German equatorial mount. The CGEM mount has a fresh, attractive, bold appearance and is capable of carrying Celestron’s higher-end SCT optical tubes (up to 11 inches) securely and vibration free. That combined with Permanent Periodic Error Correction (PEC) makes the CGEM mount an ideal platform for both visual and imaging applications.

Item #ProductStock StatusPriceShipping
11097Celestron CGEM 800
Normally Ships in 7-10 Days
$1,899.00Get Shipping Quote
Celestron CGEM 800 Schmidt-Cassegrain telescope on German equatorial mount

Celestron CGEM 800

Ergonomic Design - CGEM was designed to be ergonomically friendly with large Altitude and Azimuth adjustment knobs for quick and easy polar alignment adjustment. The internal RA and DEC motor wiring provides a clean look and an easy and trouble free set up.

Innovation - The CGEM series has a new innovative Polar alignment procedure called All-Star™ (patent pending). All-Star allows users to choose any bright star, while the software calculates and assists with polar alignment. Another great feature of the CGEM, sure to please astroimagers, is the Permanent Periodic Error Correction (PEC) which will allow users to train out the worm gears periodic errors, while the mount retains the PEC recordings.

Performance - For objects near the Meridian (imaginary line passing from North to South), the CGEM will track well past the Meridian for uninterrupted imaging through the most ideal part of the sky. The CGEM mount has a robust database with over 40,000 objects, 400 user defined programmable objects and enhanced information on over 200 objects.

Celestron's CGEM mount is the perfect fit between the Advanced Series and CGE Series. Offering the portability of the Advanced Series and the precision of the CGE.

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Optical Specifications: Celestron CGEM 800
Type Schmidt-Cassegrain
Aperture (mm) 203.2 mm
Aperture (in.) 8 inches
Focal Length 2320 mm
Focal Ratio f/10
Magnification (w/supplied eyepiece) 81X
Limiting Visual Stellar Magnitude <p><b>Limiting Stellar Magnitude</b><br /> This is a measure of the faintest star that can be seen with a telescope under ideal conditions. We include this figure for the purpose of comparing two telescopes of different apertures using a consistent scale. Many manufactures publish this specification. Unfortunately manufactures use different methods to calculate this figure, rendering the numbers useless for direct head to head comparison of different brands of telescopes. </p> <p>Limiting stellar magnitude is the sum of the naked eye limiting magnitude and the telescopic gain. The naked eye limiting magnitude varies by location due to local light pollution; therefore, it is an assumption. This figure could be 6.5 or higher at some of the darkest locations, but less than 2 in the middle of a large city. Our calculations assume a figure of 5, which one might typically find 30-40 miles from a major urban area. </p> <p>Telescopic gain is a direct function of aperture. No attempt has been made to compensate for the affects of central obstructions or different types of optical coatings.</p> 14.2 Magnitude
Accessories and Features
Included Eyepiece(s) 25mm Plossl
Finder 6x30 Optical
Go-To System Celestron NexStar system with 40,000+ object library. Flash upgradeable via the Internet.
Star Diagonal 1.25-inch prism type
Accepts 2" Eyepieces <p><b>Telescope Eyepiece Formats</b><br /> Virtually all telescope eyepieces available today conform to one of two barrel diameter standards: 1.25 or 2 inches. Most amateur astronomers will be perfectly content with 1.25" eyepieces. Two-inch eyepieces have only one inherent advantage. That advantage is a potentially larger field of view, but not every telescope can take advantage of that potential. </p> <p>A Telescope and eyepiece work together to collect parallel light rays over a large area, compress those light rays down into a smaller area, and the re-orient them so that they are nearly parallel once again. Essentially light arriving at a telescope with any given aperture is compressed into a smaller aperture or exit pupil. The ratio of the telescope aperture to eyepiece exit pupil determines the magnification.</p> <p>There are cases at very low magnifications where the eyepiece barrel diameter becomes the constraint on maximum field of view. The eyepiece barrel itself actually blocks some of the available light that the telescope is collecting, thus limiting the field of view. Two-inch eyepieces overcome this constrain by allowing a larger light cone to enter the eyepiece. We must conclude this discussion by restating that 2" eyepieces have no inherent advantage over 1.25" eyepieces other than the potential for a larger field of view when used with a telescope capable of benefiting from that advantage. </p> No
Adaptable for 2" Eyepieces <p><b>Two-inch Eyepiece Upgrade</b><br /> Some telescopes that are factory configured for 1.25" eyepieces can be upgraded to accommodate 2" eyepieces. Other telescopes are designed to handle only 1.25" eyepieces and cannot be upgraded due to their focuser size or other constraints. </p> <p>Sometimes this upgrade is possible but not recommended. This could be due to clearance issues caused by the addition of a larger 2" star diagonal,which in some cases will bottom out on the base of a fork mounted go-to telescope. This is potentially damaging the drive mechanism. In other cases the light cone exiting the telescope may not be large enough to derive any benefit from a 2" eyepiece.</p> Yes
Physical Parameters
Telescope Weight Not Specified Pounds
Tripod Weight 17 Pounds
Weight, Fully Assembled 88 Pounds
Mount Weight (excluding tripod and counterweight) 41Pounds
Counterweights 1 x 17 Lb.
Power Requirements 1.5 Amps @ 12 VDC
Power Supply Car battery adapter included
Eyepiece Calculator
Enter your eyepiece's specifications:
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Exit Pupil: <p>Exit pupil represents the diameter of the column of light exiting the eyepiece. Magnification is simply the ratio of telescope aperture to exit pupil. Fox example, using a telescope with 100mm aperture and an exit pupil of 2mm yields a magnification of 50X.</p> <p>There are both upper and lower limits to the useful range of exit pupils. The typical human eye pupil dilates to a maximum of 7mm when fully dark adapted. This figure decreases with age. Using an exit pupil that is larger than this upper limit simply spills the light onto an area of the eye not capable of receiving data. At the opposite end of the range, a smaller exit pupil means less area on the eye is collecting data. Images brightness decreases with decreasing exit pupil. Deep space objects grow dimmer rapidly as the exit pupil falls below 1 mm. The planets also start to become noticeably dimmer when the exit pupil falls much below 0.5 mm.</p> <p>Our eyepiece calculator provides warnings and error messages based upon the value of the exit pupil. These are intended to be guidelines as opposed to hard rules. There is no harm in violating these gidelines, but your enjoyment of the telescope may be diminished if you do. </p>