- 9.25" EdgeHD Optics
- CGEM Computerized Equatorial Mount
- Celestron's premium StarBright XLT coatings
- 9x50 finderscope to help accurately find objects
- Ultra sturdy 2" steel tripod with Accessory Tray
- Star diagonal provides more comfortable viewing position when observing objects that are high in the sky
- New aplanatic Schmidt telescope design produces aberration-free images across a wide field of view
- Mirror tension locks hold the primary mirror in place and reduces image shift
- Cooling vents allow hot air to be released from behind the primary mirror
- Fastar compatible for fast f/2 imaging
Computerized Mount Features
- Proven NexStar computer control technology
- 40,000 object database with over 100 user-definable objects and expanded information on over 200 objects
- Redesigned electronics deliver constant regulated power to the motors making them capable of driving the telescope even when not perfectly balanced.
- New "All-star" Polar alignment uses any bright star for a quick and accurate Polar alignment
- Software Features include: Mount Calibration, Database Filter Limits, Hibernate, five Alignment Procedures
- Flash upgradeable hand control software and motor control units for downloading product updates over the Internet
- Meridian preference for slewing - allows you to approach an object from the side of the Meridian that maximizes tracking (and imaging) time.
- Solar System alignment method - allows you to align your telescope and view the moon and planets during the day
- Custom Rate 9 feature allows you set maximum slew rate
- Tandem mode allows you to star align the mount even when positioned for tandem scope use.
- Custom database lists of all the most famous deep-sky objects by name and catalog number: the most beautiful double, triple and quadruple stars; variable stars; solar system objects and asterisms
- Permanent Programmable Periodic Error Correction (PEC) - corrects for periodic tracking errors inherent to all worm drives
- Drive Motors - Low Cog DC Servo motor with integrated optical encoders offer smooth, quiet operation and long life. The motor armatures are skewed to minimize cogging which is required for low speed tracking
- Internal Cable wiring for trouble-free setup and transportation
- Designated six-pin RJ-12 modular jack, ST-4 compatible guide port
- Autoguide port and Auxiliary ports located on the electronic plate for long exposure astrophotography
- Double-line, 16-character Liquid Crystal Display Hand Control with backlit LED buttons for easy operation of goto features
- RS-232 communication port on hand to control the telescope via a personal computer
- Includes NexRemote telescope control software, for advanced control of your telescope via computer
- GPS compatible with optional SkySync GPS Accessory
- Precision machined 40 mm diameter steel Polar shafts supported by multiple tapered roller bearings and ball bearings.
- Secure power plug ensures that the mount's power source is not accidentally disconnected
ITEM # 11081
The CGEM 925 HD combines Celestron's newly designed CGEM Computerized Equatorial mount with its new EdgeHD optical system. With over 9 inches of aperture and our premium StarBright XLT coatings, the CGE Pro 925 HD gives you over 1000 times the light gathering power than the unaided eye. Designed to give diffraction limited performace, the CGEM 925 HD has established itself as a premier astro-imaging telescope.
New Optical Design
The EdgeHD optical system combines all the compact power popularized by the SCT and combines it with an improved high definition optical system for wide field, astrograph quality images. As a visual instrument, EdgeHD optics delivers pin point images even with your widest field eyepiece. You can search for all of the Messier Catalog objects, and see hundreds of other equally interesting NGC, IC and Caldwell objects with amazing clarity. For astroimaging, the EdgeHD optics produces aberration-free images across your favorite CCD or DSLR camera. All EdgeHD optics are designed to produce an extremely flat focal plane precise enough to match the strict tolerances of the largest commercial CCD detectors, allowing all stars to be in tight focus to the very edge of the chip.
The Celestron Product Development team has released a whitepaper outlining the technology behind EdgeHD. This paper describes the development goals, design decisions, optical performance, and their practical realization in 8-, 9.25-, 11-, and 14-inch apertures. We include cross-sections of the EdgeHD series, comparative spot diagrams for the EdgeHD and competing “coma-free” Schmidt-Cassegrain designs, a table with specifications for visual and imaging, graphics showing how to place sensors at the optimum back-focus distance, and details on the construction and testing of the EdgeHD telescope series.
Some companies boast that their telescopes give diffraction limited stars in the very center of the field of view . EdgeHD optics not only produce diffraction limited stars on axis, but maintains diffraction limited stars across the entire field of view of many of the most popular astrophotography cameras. Even at the very edge of a full frame camera chip, the EdgeHD 9.25 delivers diffraction limited stars of only 1 arc seconds.
The EdgeHD 9.25 optics produces a focal plane almost 9 times flatter than the standard equivalent SCT telescope with diffraction limited stars across the entire Nikon D3 or Canon 5D field of view!
Along with the newly designed optics, the EdgeHD also has re-designed mechanics guaranteed to help you get the maximum performance from your instrument. Features include:
Mirror locks – To hold the mirror in place and reduces image shift during imaging.
Tube vents - Each vent has an integrated 60 micron micro-mesh filter allowing hot air to be released from behind the primary mirror.
Fastar versatility – All EdgeHD optical tubes are equipped with a removable secondary mirror for fast f/2 CCD imaging. Not only does imaging in the FASTAR configuration allow for exposure times that are 25 times faster than at f/10, but also yields a field of view five times wider. Perfect combination for imaging your favorite wide field objects in a fraction of the time. (FASTAR imaging require a third party lens assembly in place of the secondary mirror).
Axiom Eyepiece - EdgeHD 9.25 optical tubes come with Celestron's top of the line Axiom eyepiece. With a 23 mm focal length and 82° AFOV, you get incredible combination of power and wide field of view. Plus each Axiom eyepiece is optimized to deliver pin point images when used with a flat field telescope.
Learn more about the benefits and features of this new optical system by going to the EdgeHD web page.
The CGEM™ mount has a fresh, attractive, bold appearance and is capable of carrying Celestron’s higher-end SCT optical tubes (up to 11") securely and vibration free which is ideal for both imaging and visual observing.
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™ . 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 gear's 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, 100 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.
|Optical Tube Info:|
|Aperture (mm)||235 mm (9.25 in)|
|Focal Length||2350 mm (93 in)|
|Focal Length of Eyepiece 1 (mm)||23 mm (0.91 in)|
|Magnification of Eyepiece 1||102 x|
|Mount Type||CGEM Computerized Equatorial|
|Tripod||Adjustable, Stainless Steel|
|Power Requirements||Car battery adapter|
|Highest Useful Magnification||555 x|
|Lowest Useful Magnification||34 x|
|Limiting Stellar Magnitude||14.4|
|Resolution (Rayleigh)||0.59 arc seconds|
|Resolution (Dawes)||0.49 arc seconds|
|Light Gathering Power (Compared to human eye)||1127 x|
|Apparent Field of View||0.8 °|
|Secondary Mirror Obstruction||3.35 in (85 mm)|
|Secondary Mirror Obstruction by Diameter||36%|
|Secondary Mirror Obstruction by Area||13%|
|Optical Coatings||Starbright XLT Coatings|
|Optical Tube Length||22 in (559 mm)|
|Total Telescope Kit Weight||113 lbs (51 kg)|
|Weight of Counterweights||1 x 11 lbs, 1 x 17 lbs|
|Slew Speeds||Nine slew speeds|
|Tracking Rates||Sidereal, Solar and Lunar|
|Tracking Modes||EQ North and EQ South|
|Alignment Procedures||2-Star Align, Quick Align, 1-Star Align, Last Alignment, Solar System Align|
|Computer Hand Control||Double line, 16 character Liquid Crystal Display; 19 fiber optic backlit LED buttons|
|Database||40,000+ objects, 100 user defined programmable objects. Enhanced information on over 200 objects|
|GPS||Optional SkySync GPS Accessory|
|Warranty||2-year Telescope Warranty|
Warranty 2 Years
For two years, Celestron will cover repairs or replacement of this product in cases of defective components. This warranty shall be void and of no force of effect in the event a covered product has been modified in design or function, or subjected to abuse, misuse, mishandling or unauthorized repair. Further, product malfunction or deterioration due to normal wear is not covered by this warranty. For more details, visit our Warranty page.
Where to Buy
You can count on our Premier Select dealers to offer an extensive selection of telescopes, binoculars, and microscopes in stock for immediate delivery. As our trusted partners, they provide advanced product expertise and superior customer service.
Celestron Premier Plus dealers carry a range of Celestron products. As our trusted partners, they provide advanced product expertise and superior customer service.
- Telescope Maintenance (English, French, German, Italian, Spanish)
- Telescope Basics (English, French, German, Italian, Spanish)
- Astronomy Basics (English, French, German, Italian, Spanish)
- Celestial Observing (English, French, German, Italian, Spanish)
- EdgeHD Optics Manual
- CGEM Series Manual
- Drivers and Software
- PEC Tool v.1.0.18
- Product Info Sheets
- EdgeHD Optics Info Sheet
- White Papers
- Whitepaper EdgeHD Optics
- Knowledgebase Articles
- Will I be able to use my standard Celestron SCT T-adapter 93633-A to attach my SLR camera to the EdgeHD?
- How do my EdgeHD mirror support knob flexible tension clutches work? Will they interfere with focusing my scope?
- My CGEM mount is moving in the wrong direction when I use the direction arrows. What is wrong? How can I change the direction of the direction buttons?
- What is the optimized image circle for the EdgeHD OTAs and Reducers?
- My EdgeHD optical tube assembly (OTA) has four small tapped holes along the front rim. What are they for?
- I have a CGEM mount and I need to use it at latitudes below 15 degrees or above 70 degrees. Can I do that?
- How do I use the polar axis finderscope for the CGEM mount?
- I want to permanently pier-mount my CGEM. What size is the hole on the head holding the central rod?
- I have a small-chip CCD camera or APS-C format DSLR or webcam with an adapter that isn’t made for the EdgeHD. What problems will I have with image quality using this system since it’s not the optimum spacing size?
- Are there any additional specifications on the CGEM/CGEM DX Mount?
- What is the threading on the outside of my Celestron GoTo mount’s power jack?
- My Celestron mount is making a high pitched whine or hum even when it’s not moving. Is this a problem?
- What are the differences between the CGEM and CGEM DX mounts?
- Which Polar finder should I use for my Equatorial mount
- Is there vignetting with the EdgeHD optics and reducers on a full-frame image sensor?