Celestron EdgeHD - premium coma-free, flat-field, aplanatic Schmidt-Cassegrain telescopes

More Information  · Supplied Accessories  · Recommended Accessories  · Images of Some Features Price $6,899.00 List Price $12,597.95 Highest Useful Magnification 470x Visual Limiting Magnitude 14.4 Focal Length 2350mm Focal Ratio f/10 Resolution 0.49 arc seconds Aperture 9.25" Net Weight 176 lbs. Heaviest Single Component 75 lbs. Warranty 2 years

• 9¼” EdgeHD high definition aplanatic Schmidt-Cassegrain optics
• 90 pound payload capacity high precision CGE Pro German equatorial mount
• NexStar go-to computer hand control with 40,000+ object database
• StarBright XLT optical multicoatings for the highest possible light transmission
• 9 x 50mm finderscope
• 23mm 2” Axiom 82° field eyepiece (102x)
• NexRemote software to control the telescope via computer
• 2-year warranty

    The Celestron CGE Pro 925HD telescope puts unique new 9.25” aperture aplanatic (free from coma and corrected for spherical aberration) EdgeHD high definition/high contrast Schmidt optics on an observatory-grade Celestron CGE Pro go-to German equatorial mount. The advanced EdgeHD optical system uses a dedicated dual-element field flattener lens made from premium Schott optical glass in its central baffle tube to reduce off-axis coma and produce aberration-free images across a wide 42mm image circle (as large as the diagonal of a 35mm negative or large format CCD chip and ideal for astrophotography). And those images look superb through the supplied ultra-premium 23mm 2” Celestron Axiom 82° field eyepiece.

   In addition to reduced off-axis coma, the EdgeHD optics deliver an astrograph-quality focal plane more than three times flatter than standard Schmidt-Cassegrains and dramatically flatter than competing coma-free designs. Stars are smaller and more concentrated, creating brighter images and allowing you to see down to a fainter magnitude than other equally-sized telescopes. You see sharp and point-like stars to the very edges of some of the largest CCD and DSLR chips available today.

    For the ultimate in brightness and contrast, the CGE Pro 925HD optical tube has state-of-the-art Starbright XLT multicoatings. Its light grasp is approximately 1125 times that of even the sharpest dark-adapted eye, revealing to your eye and camera star clusters, nebulas, planets, and galaxies in amazing detail. The Fastar-compatible optical tube even allows imaging down to an incredibly-fast f/2 focal ratio using optional accessories.

    The Celestron CGE Pro 925HD’s observatory-grade CGE Pro mount can carry payloads of up to 90 pounds, more than four times the weight of the scope’s 21 pound 9.25” optical tube. This makes this mount/OTA combination rock-steady, no matter how many heavy visual and imaging accessories you add to the system.

   The scope’s advanced NexStar computer hand control makes finding over 40,000 of those stars and objects easy and automatic, so you can spend more time looking at those objects, rather than looking for them.

   Granted, many people might feel that a 154 pound mount with a 90 pound payload capacity is a case of overkill for a 21 pound optical tube. For those who must travel to a dark sky site to use their scope, that might indeed be the case. That’s why Celestron also puts the same 9.25” EdgeHD optical tube on the lighter CGEM mount (#CGEM9HD), to make travel easier. However, for those who have a permanent observatory site and are looking to grow their system in stages, the CGE Pro 925HD makes a sensible choice as the heart of a bigger scope array to come. You can add virtually any size or weight optical tube you like later on, without having to upgrade your mount. And while you are waiting for your aperture fever to become affordable, the superb flat-field reduced-coma optics of the 9.25” CGE Pro 925HD are big enough, and good enough, to keep you happily observing and imaging for years to come, and even for years after you get the “big” optical tube to put on your CGE Pro mount.

   Starbright XLT optics
   CGE Pro mount
   CGE Pro NexStar computer
   Celestron EdgeHD optics

This Telescope’s Optical System . . .

• EdgeHD aplanatic Schmidt-Cassegrain optical tube: 9.25" aperture (2350mm focal length f/10). Guaranteed diffraction-limited optical performance, free from coma and corrected for spherical aberrations (aplanatic design). The 22" long aluminum optical tube has a large handle on the rear cell and weighs only 21 pounds, making it easy to transport and assemble the scope in the field. For more details, click on the “EdgeHD optics" icon above.

• Starbright XLT fully multicoated optics: This high transmission/high reflectivity optical coatings package gives you visibly higher light transmission for brighter deep space images and shorter exposure times during CCD and 35mm photography. It also increases the contrast on subtle lunar, planetary, and nebula details when compared with a scope with ordinary coatings or multicoatings. For more details, click on the “Starbright XLT" icon above.

• Tube vents: Two cooling vents on the rear cell allow warm air to be released from behind the primary mirror when the scope is taken out for a night’s observing or imaging. This shortens the amount of time needed for the optics to cool down to ambient air temperature for peak performance. Each vent has an integrated 60 micron micro-mesh filter guaranteed to let warm air out without letting dust in.

• Fastar compatible: For the ultimate in wide-field catadioptric imaging, the EdgeHD optical tube is Fastar compatible to allow CCD imaging at a blazingly-fast f/2 focal ratio. An optional Fastar lens assembly lens replaces the scope’s removable secondary mirror (an exchange that takes only a few minutes). Your CCD camera is attached to the Fastar lens. This puts your camera at the f/2 position in the center of the Schmidt corrector lens at the front of the scope, rather than in its normal f/10 position at the Cassegrain focus at the rear.
     Using the Fastar system and a sub-$1500 Orion Star Shoot Deep Space Imager Pro CCD camera, the 9.25" CGE Pro 925HD will record a wide 168 x 112 arc minute field – a long axis almost six times the diameter of the full moon, an immense field for a scope of this size. To assure repeatability when you switch between Fastar and conventional imaging, the scope’s optical tube is opto-mechanically aligned on a laser bench during manufacture so that all components are axially symmetric in any configuration.

• Focusing: Focusing is accomplished by turning a knob at the rear of the scope body that moves the primary mirror fore and aft along a central baffle tube to adjust the focus. The Celestron focusing mechanism is supported by two pre-loaded ball bearings, minimizing the “mirror flop" typical of bushing focus mechanisms that causes image shift during critical focusing.

• Mirror locks: Flexible tension locks hold the mirror in place after correct focus is achieved for imaging and reduce image shift when rotating the tube around the mount (when moving past the zenith during astrophotography, for example). Unlike other designs that have only one locking knob located off to one side of the mirror, the Celestron system uses three locks equally spaced around the mirror to distribute the mirror locking force symmetrically. The focuser itself acts as one of the locks, while two flexible rods spaced 120° away in either direction act as the second and third locks. Controlled by variable tension knobs on the rear cell, these rods act in conjunction with the focuser to hold the mirror in place without putting any asymmetrical force or pressure on the mirror. This keeps the image centered in the eyepiece (or chip) no matter what the orientation of the optical tube.

• Finderscope: 9 x 50mm straight-through achromatic design, with a wide 5.8 degree field of view, mounted in a spring-loaded easy-adjust quick release bracket..

• Star diagonal: 2" first-surface mirror type, with 1.25" adapter.

• Eyepiece: premium 2" 23mm 82° field Axiom (102x), a much higher quality eyepiece than those supplied with competitive scopes. The eyepiece field of view is 0.8° wide, over 50% larger than the full moon, and an exceptionally wide field for the magnification.

This Telescope’s Mount . . .

• Heavy duty CGE Pro computerized German equatorial mount: The CGE Pro mount includes dual-axis slewing/tracking motors on each axis for go-to computer control. There are nine motor drive speeds: 0.5x and 1x sidereal for guiding; 4x, 8x, 16x, and 64x for centering; and 0.5°, 2°, and a fast 5.5° per second for slewing. The inherent drive accuracy (periodic error) of the observatory-grade CGE Pro mount is a very good +/- 9 arc seconds or better, which can be further reduced by using the scope’s permanent periodic error correction program.

• Powering the CGE Pro 925HD: The mount comes with a car battery cord to operate from the cigarette lighter plug of your car or from a rechargeable 12VDC battery pack. The 17 amp hour capacity Celestron Power Tank #4517V is recommended and will operate the scope all night long without danger of running out of power.

• Polar alignment: To make a casual polar alignment for visual use quick and easy, there’s a latitude scale with large ergonomically-friendly altitude and azimuth adjustment knobs. No polar alignment finderscope is available to aid in the precise polar alignment required for long exposure astrophotography, nor is any needed. A unique Celestron All-Star Polar Alignment program built into the NexStar hand control helps you do a very precise computerized polar alignment in mere minutes, using any bright star, even when Polaris is hidden by trees or buildings. The program works in both northern and southern hemispheres.

• Adjustable height tripod: The 52 pound tripod and electronics pier has 2.75" diameter stainless steel legs with dual leg braces for rigidity and excellent vibration damping characteristics. The top brace forms a convenient tray that holds eyepieces and accessories to keep them up out of the dew-soaked grass.

• Mounting the scope: A dovetail slot on the top of the 75 pound mount head holds the long dovetail slide bar mounted under the optical tube. This allows you to slide the optical tube fore and aft in the dovetail slot to quickly and precisely balance the optical tube in declination when you add or subtract accessories, eliminating the need for an extra counterweight to balance a camera or other accessories. Three large hand-tighten knobs in the oversized dovetail mounting platform hold the optical tube very securely in place. With a deadweight lift of 75 pounds to install the equatorial head onto the tripod, it might be prudent to have a second person assist you when assembling your CGE Pro mount.

• Balancing the scope: The sliding 22 pound counterweight is locked in place on the removable 5 pound counterweight shaft with a single large hand-tighten knob. This makes it easy to rebalance the scope in right ascension if you add heavy photographic accessories. For more details, click on the “CGE Pro mount" icon above.

• NexStar computer hand control: The supplied NexStar computer hand control has a built-in database of more than 40,000 stars and objects that it can find and track for you. These include the complete RNGC, Messier, Caldwell, IC, and Abell catalogs; selected SAO stars; the planets, the Moon, and others. The 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; non-planetary solar system objects; and asterisms.

• The NexStar display: All of the database and scope operation information is displayed on a double line, 16-character, liquid crystal display on the hand control. There are 19 fiber optic backlit LED buttons to make it easy for you to control the computer without affecting your dark-adapted vision. The NexStar hand control can provide an easily-visible illuminated right ascension and declination readout of the scope’s position on the sky. This provides much greater accuracy than conventional (and hard to see at night) manual setting circles for star-hopping or locating objects by their celestial coordinates alone, should you want to observe the old-fashioned way without using the computer to find objects for you.

• Some NexStar features: The software built into the NexStar hand control includes many, many features and programs discussed at greater length by clicking on the “CGE Pro NexStar computer" icon above. An RS-232 communication port on the hand control allows you to operate the telescope via a personal computer using the supplied RS-232 cable and NexRemote software CD-ROM. The hand control and motor control software is flash-upgradeable to allow you to download the latest product updates over the Internet to keep your CGE Pro mount always at the cutting edge of technology. An autoguider port is located on the electronic pier for guided, but unattended, long exposure astrophotography.

• Aligning on the sky: Five different alignment methods are built into the NexStar computer – 2-star align, quick align, 1-star align, last alignment, and solar system align – allowing you to choose a level of computer accuracy in automatically finding objects with which you are comfortable. Alignment is easily accomplished in only a few short minutes. You can be observing in less than 15 minutes after you first take the scope outdoors. There’s even a new and unique “All-Star" software-assisted alignment of the mount’s polar axis using a single bright star that will have you ready for imaging before it’s even dark enough to see the North Star. For more details, click on the “CGE Pro NexStar computer" icon above.

• NexRemote Software: The supplied NexRemote telescope control software allows you to control your CGE Pro 925HD from your personal computer or laptop. NexRemote provides full emulation of every aspect of the Celestron computerized hand control including: alignment in any tracking mode; go to any database object; setup of user objects; hibernation; connection to popular planetarium programs; etc.
     The NexRemote software adds powerful new features that let you keep your eyes on the stars instead of the computer screen. It enables talking computer speech support using your computer’s built-in speaker; controls the objects you want to see and the order that you see them; creates and saves custom tours by launching NexTour; connects your personal GPS device to NexRemote using NexGPS; and more. You can download NexRemote updates online to use the latest features. The NexRemote software includes an RS-232 cable to connect your CGE Pro 925HD to a PC.

• Two-year warranty: All Celestron go-to telescopes have a two-year warranty, double that of competitive go-to scopes.