Celestron CGX-L 925HD 9.25" SCT with EdgeHD High Definition Optics 12075

The new Celestron CGX-L 925HD telescope puts 9.25" aplanatic EdgeHD high definition/high contrast optics on the CGX-L go-to German equatorial mount to give you a superlative true astrographic-quality telescope.

The Celestron CGX-L 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).

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 CGEX-L 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 CGX-L 925HD's CGX-Lmount can carry payloads of up to 75 pounds, more than three 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 126 pound mount with a 75 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 CGEMII mount (#CGEMII9HD), to make travel easier. However, for those who have a permanent observatory site and are looking to grow their system in stages, the CGX-L 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" CGX-L 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 CGX-L mount.

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 in teh support tab 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.

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.

This Telescope's Mount . . .

The German equatorial mount has long been the favored choice of astronomy buffs and astrophotographers because of its stability and portability. It is more stable because the center of gravity is directly over the center of its base, and more portable because it can be broken down into smaller component parts than a fork-mount telescope for easy storage and transportation.

For astrophotography, the German equatorial mount offers easier balancing; unlimited space at the rear of the telescope tube to mount a long camera equipment train that can't bump into the drive base, as is the case with many fork-mounted scopes; and whole sky access that many fork-mounted scopes can't achieve.

Celestron has looked to update the way that people interact with their equipment. This quest has brought out a new EQ Mount Series, the CGX. This particular model in the series is the CGX-L and boasts a 75 pound payload capacity.

Heavy duty mount head: The Celestron CGX-L is a newly-designed high payload capacity/high precision go-to German equatorial mount that epitomizes all of these German equatorial mount virtues. With its full 75 pound payload capacity it will carry Celestron SCT/HD optical tubes up to 14" in aperture, as well as virtually any other optical tube and accessory payload weighing up to 75 pounds.

New features are everywhere in the mount head:

1. Ergonomic handles help you move the 47 pound head with ease. That's right; the head weighs 47 pounds and will carry 75. It is an incredible load to weight ratio.

2. Additional accessory ports built into the dovetail saddle plate of the equatorial head. There are two auxiliary ports as well as an autoguider port. The internal cabling of the CGX-L mount works hand in hand with these new ports on the saddle helping the imager in all of us manage our cables.

3. The dovetail saddle plate is longer for added stability and will also accept both Vixen/AVX and Losmandy/Celestron D Style dovetails.

4. There are built in home and limit sensors. The home sensor will take the scope back to its home position at any time and the limit sensor will prevent the mount from slewing past a certain point.

5. There are also built-in mechanical hard stops to prevent an instrument from damage should you forget to lock the mount.

Mount drive system: The CGX-L mount head contains 144mm worm wheels in both Right Ascension and Declination. The improved drive system uses a belt-driven worm gear that is spring loaded. The significance of this is it allows the drive to maintain optimum gear mesh for smoother tracking and less backlash.

The mount requires 2.5 amp 12 VDC power to operate. The maximum 2.5 amp power draw happens only briefly when accelerating to the high speed slewing mode from a standing start. Normal power draw with a well-balanced payload is generally considerably less than half the maximum draw. 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 mount all night long without danger of running out of power.

Specially designed power management electronics deliver constant regulated power to the motor so that it is capable of driving the mount even when your scope not perfectly balanced. This allows the CGX-L to have the payload capacity of that of much larger (and expensive) mounts without sacrificing smooth tracking motion and pointing accuracy across the entire sky.

Polar alignment: To make a casual no-tool polar alignment for visual use quick and easy, there's a latitude scale with large ergonomically-friendly altitude and azimuth adjustment knobs. If serious long exposure astrophotography is in your plans, the special All-Star Polar Alignment software described below allows you to choose any bright alignment star for a software-assisted alignment of the mount's polar axis, even if you can't see the North Star. The mount also has upgraded adjustments for Latitude and Azimuth. Large one hand knobs make moving a full loaded mount head a dream with a simple twist of the wrist.

Counterweight: The CGX-L mount comes with one 22 pound counterweight. The counterweight locks in place on the 5 pound steel counterweight shaft with a single hand-tighten knob, making it easy to rebalance your scope in right ascension if you add heavy photographic accessories. If needed, optional counterweights are available to balance very heavy loads.

Heavy duty tripod: The CGX-L mount's adjustable height Super HD tripod has 2.75" diameter stainless steel legs. The height adjustment leg locks are on the inside of the tripod legs to keep them from snagging on clothing in the dark. The tripod uses a dual leg support for maximum rigidity, with an upper leg brace to provide an outward preload and a lower leg brace providing inward tension. The upper leg brace forms a convenient tray that holds eyepieces and accessories, as well as a slot to hold your smart phone or tablet, to keep them up out of the dew-soaked grass. This tray is a new design that will allow you to keep it attached while you fold the legs up.

Mounting an optical tube: Optical tubes are installed on the CGX-L mount using a slot on the mount head that accepts a Celestron CGE-style/Losmandy D-plate dovetail or a Celestron AVX/CG5/Vixen slide bar. This allows the optical tube to be quickly and precisely balanced fore and aft on the mount in declination, eliminating the need for an extra counterweight to balance a camera or other accessories. Setup and takedown times are exceptionally fast, with large hand-tighten knobs holding the optical tube in place.

NexStar computer hand control: The NexStar computer hand control of the CGX-L mount has a built-in database of more than 40,000 stars, deep space objects, and solar system objects it can locate 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. It contains enough fascinating objects to keep you busy observing for the rest of your life.

You can also store and edit the right ascension and declination of 100 objects of your own choosing, such as the comet and asteroid coordinates published monthly in Astronomy and Sky & Telescope magazines. The computer control can quickly find any of those objects at your command, and track them with high accuracy for visual observing or astrophotography.

All of the database and scope operation information is displayed on a double line, 16-character, liquid crystal display on the hand control. This display leads you through the steps necessary to line up the scope on the sky, locate objects, control scope functions like the brightness of the hand control display, and much more. It shows you basic information about the object being viewed (such as the object's name, catalog designation, type, magnitude, and so forth). In addition to this basic information, there is enhanced information on over 200 of the most note-worthy objects. The display can also show you the right ascension and declination coordinates at which the scope is aimed.

Alignment on the sky and go-to accuracy: No polar alignment finderscope is available for the CGX-L mount, nor is any needed. A unique Celestron All-Star Polar Alignment program built into the NexStar hand control helps you do a very precise polar alignment in mere minutes for long exposure astrophotography. It works in both northern and southern hemispheres.

To accurately polar align your scope, first do a reasonably-accurate mechanical alignment of the mount on the celestial pole by eye. To make this initial alignment quick and easy, there's a latitude scale and fine adjustment controls in both altitude and azimuth. Next, use the mount's standard two-star alignment method to align your scope on the sky. Select a suitable bright star from the NexStar hand control's data base and slew your telescope to the star. A star near the meridian and close to the celestial equator will give the most accurate alignment results. Then, press the Align button on the hand control and select Polar Align: Align Mount from the hand control menu. Your telescope will re-slew to the alignment star and ask you to center it in the eyepiece in order to "Sync" on the star. After you sync on the star, your telescope will automatically slew to the position that the star should be at if your mount was accurately polar aligned. Use the mount's altitude and azimuth adjustment knobs to place the star in the center of the eyepiece and press the Align button. That's all there is to it! Your CGE Pro mount is now accurately aligned on the celestial pole.

Although the telescope's tracking may be very good after alignment, pointing accuracy may need to be improved (particularly if you are trying to located small objects on a CCD chip), depending on how close your initial mechanical alignment was on the pole, and by much the mount had to be moved during polar alignment. If that's the case, you can easily update your telescope's star alignment in a minute or two if necessary.

Once polar aligned, several different sky alignment methods are built into the NexStar computer to line up the scope on the celestial sphere, allowing you to choose a level of computer accuracy in automatically finding objects with which you are comfortable. These include 2-Star Align, Solar System Align, Last Alignment, Quick Align, and 1-Star Align,

With just a standard hand control alignment, the CGX-L computer has the ability to center a star in your telescope's eyepiece or on a CCD chip to within 5 arc minutes. Using the NexStar computer's advanced pointing features (such as Calibration Stars, Sync, and Precise Go-To) further improves the pointing accuracy to as low as 1 arc minute in the desired region of the sky. The high precision pointing subroutine (Precise Go-To) in the computer lets you point accurately at objects that you want to photograph that are too dim to be seen though the scope. Other software features include: database filter limits, a mount hibernate mode, and user-defined slew limits.

GPS compatible: In addition, the NexStar computer hand control is GPS-compatible (using an optional inexpensive CN16 GPS module) for full GPS (Global Positioning System) satellite accuracy. Once the scope is approximately polar aligned, the 16-channel CN16 GPS system uses signals from government satellites to calculate the scope's location on earth with an accuracy measured in meters. The system also calculates the current time based on the split second accuracy of the GPS time signals. After the CN16 quickly completes these calculations and enters the information into the computer control for you automatically, the computer then orients the scope with the sky, slews to a pair of guide stars, asks you to confirm that the stars are in the center of the field (and center them if they're not precisely aligned), and then starts finding and tracking over 40,000 objects for you at your command. With the CGX-L go-to mount and the CN16, orienting the scope in time and space on earth and aligning your telescope on the sky becomes almost as easy a task as simply turning on your CGX-L mount.

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