Celestron CGEM-II 800 EdgeHD Telescope - CE-12017

  • Rounder, more pleasing stars with improved resolution and limiting magnitude.
  • A 203 mm (8-inch) EdgeHD Corrected Schmidt-Cassegrain Telescope.
  • Produces Aberration-Free Images.
  • Focal Ratio of f/10.
  • Fastar Compatible Down to f/2.
  • Internal Cable Wiring.
  • Smooth and Quite Operation.
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  • Regular price $2,649.00

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Celestron CGEM-II 800 EdgeHD Telescope - CE-12017

The Celestron CGEM-II 800 EdgeHD Telescope is capable of carrying Celestron's higher-end SCT optical tubes (up to 11-inches) securely and vibration free which is ideal for both imaging and visual observing.

Superior mount performance combined with 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. When it comes to the Celestron HD series coupled with Celestron's StarBright XLT coating group on every surface, EdgeHD optics gives you maximum light throughput across the widest visual and photographic spectrum. It's a vision you'll never forget.

Features of the Celestron CGEM-II 800 Telescope

Ergonomic Design 

The Celestron CGEM-II mount 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 provide a clean look and an easy and trouble-free set-up.


The Celestron CGEM-II 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-II, sure to please astro-imagers, 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. Furthermore, the new mount model is equipped with a dual saddle capable of mounting both predominant kinds of Dovetail.


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


  • A 203 mm (8-inch) EdgeHD Corrected Schmidt-Cassegrain Telescope
  • EdgeHD aplanatic, flat field SCT optics for pinpoint stars to the edge of the largest imaging sensors and widest eyepieces.
  • Aluminum optical tube with tube vents featuring an integrated 95-micron mesh filter allows hot air to be released from behind the primary mirror.
  • Mirror support knobs hold the mirror in place and reduce image shift during imaging.
  • Versatile design accommodates 3 focal ratios: native f/10, f/7 with the addition of a focal reducer, or ultra-fast f/2 imaging with a removable secondary mirror and third-party accessories.


  • 2-inch steel legs with height index marks for quick leveling.
  • 40,000 object database with over 100 user-definable objects and expanded information on over 200 objects.
  • Internal cabling throughout for worry-free remote operation.
  • Low cog DC Servo motor with integrated optical encoders offer smooth, quiet operation.
  • Able to track past the meridian allowing seamless imaging.
  • Permanent periodic error corrections allow users to train out the worm gears periodic errors once, while the mount retains the PEC recordings.
  • Software features include Mount Calibration, Database Filter Limits, Hibernate, five Alignment Procedures, and user-defined slew limits.
  • Built-in polar alignment program to polar align on any star in the sky.
  • Longer clutch levers to make tightening and loosening of clutches easier.
  • Custom database lists of all the most famous deep-sky objects by name and catalog number.
  • Solar System alignment method allows to view the moon and planets during the day.
  • Permanent Programmable Periodic Error Correction (PEC) corrects periodic tracking errors inherent to all worm drives.
  • Custom Rate 9 feature allows setting maximum slew rate.
  • Tandem mode allows to star align the mount even when positioned for tandem scope use.
  • RS-232 communication port on hand control to control the telescope via a personal computer.
  • Includes NexRemote telescope control software, for advanced control of telescope via computer.
  • Precision machined 40 mm diameter steel Polar shafts supported by multiple tapered roller bearings and ball bearings.
  • GPS-compatible with optional SkySync GPS Accessory.


Included Technology

All-Star Polar Alignment

Get ready for a night of astroimaging with your mount faster than previously thought possible with All-Star Polar Alignment. This innovative software solves the time-consuming problem of trying to pinpoint the North Celestial Pole.

EdgeHD Optics

Celestron’s aplanatic EdgeHD optics revolutionized astroimaging. This award-winning optical system reduces visual defects like field curvature and coma, creating an ultra-flat field for pinpoint stars all the way to the edge of today’s largest imaging sensors.

Compatible Technology


The new Lithium Phosphate (LiFePO4) battery chemistry has significant advantages over other battery chemistries, great for those Astronomers on the go.

Starsense Technology

Celestron’s patented StarSense Technology makes it easier than ever to locate objects in the night sky, even if you’ve never used a telescope before. Turn it on and push ‘Align.’ In about three minutes, you’re ready to observe!


WiFi technology encircles the globe in a web of connectivity, knowledge, and information. Now, Celestron is using that same technology to allow stargazers to connect to the night sky and enhance their experience of the cosmos in fun and unique ways.


Aperture203 mm (8")
Back Focus133.35mm
Camera/Eyepiece Connection2”x24 tpi
Corrected Image Circle42mm
Dawes Limit0.57 arcseconds
Dew Shield Size226mm
Drive TypeLow cog DC servo motors
Focal Length2032 mm
Focal Ratiof/10
Free ShippingYes
Head DesignEquatorial
Highest Magnification406x
Instrument Capacity40 lbs
Latitude Range15 to 70 Degrees
Light Gathering Power841x
Limiting Magnitude15.3
Mount Head Weight40lbs
Optical DesignModified SCT
PortsAutoguide Port
PortsHand Controller
PortsUSB 2.0
Power Consumption12V DC 3.2A
Secondary Obstruction68.6mm
Slew Speed5 Degrees Per Second
Telescope ConnectionDual Vixen & Losmandy
Total Weight77 lbs
Tracking ModesEQ North
Tracking ModesEQ South
Tracking RatesLunar
Tracking RatesSidereal
Tracking RatesSolar
Tripod Weight20 lbs
Tube Diameter226mm
Tube Length432mm
Tube Weight14 lbs
Warranty2 Year Warranty


  • Celestron's CGEM-II 800 EdgeHD, 203 mm (8-inch) Aperture Corrected Schmidt-Cassegrain OTA.
  • Celestron CGEM-II (Computerized German Equatorial Mount).
  • Adjustable Tripod with 2-inch Steel legs.
  • Hand Controller.
  • Accessory Tray/ spreader.
  • 1.25-inch Star Diagonal.
  • 9 x 50 Optical Finder.
  • 1.25-inch Eyepiece, 40 mm Plossl (51x magnification). 
  • DC Cigarette Lighter Adapter.
  • (1) Counterweight, 17-pound.
  • CD ROM Software: NexRemote.
  • 2 Year Manufacturer's Warranty.
Customer Reviews
4.0 Based on 2 Reviews
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Donald K.
United States United States
Not yet

I will not have my observatory until March so have not had the scope and mount in observing mode. I have done the finder scope alignment and I do like the spring loading feature on the rear of the mount. The slewing is a little loud in speeds 8 and 9 but pretty quite in the slower speeds. The unit went together easily and is quite robust. I think the lock lever does conflict a little with the knobs to tighten the dovetail, but it is a minor issue. I will put it through it’s paces come spring and maybe do another review.

John C.
United States
No complaints

There’s a lot of hype about this company....I’ve done over 3500.00 worth of biz with them and NO complaints .....john cole