The Celestron CGEMII 1100HD telescope puts unique new large aperture 11” aplanatic (free fromcoma and corrected for spherical aberration) EdgeHD highdefinition Schmidt optics on a precision Celestron CGEM II go-to Germanequatorial mount. The advanced EdgeHD optical design – a Sky & Telescope Hot Product for 2010 – has a dual-element field flattener lens made from premiumSchott optical glass mounted in its central baffle tube. The field flattenerreduces off-axis coma and produces aberration-free images across a wide 42mmimage circle (as large as the diagonal of a 35mm negative or large format CCDchip and ideal for astrophotography). And those images will look superb throughthe supplied ultra-premium 82° field 23mm 2” Celestron Axiom eyepiece.
In addition to reduced off-axis coma, the EdgeHD opticalsystem delivers an astrograph-quality focal plane more than three times flatterthan a standard Schmidt-Cassegrain telescope and dramatically flatter thancompeting coma-free designs. Stars are smaller and more concentrated, creatingbrighter images and allowing you to see down to a fainter magnitude than otherequally-sized telescopes. You see visibly sharp and point-like stars to thevery edges of some of the largest CCD and DSLR chips available today.
Celestron’s renowned Starbright XLT multicoatings on every optical surface giveyou maximum light throughput across the widest possible visual and photographicspectrum. The big aperture CGEM II 1100HD’s immense light grasp, almost 1600times that of even the sharpest dark-adapted eye, reveals star clusters,nebulas, planets, and galaxies in amazing visual and photographic detail. TheFastar-compatible optical tube allows imaging down to an incredibly-fast f/2focal ratio using optional accessories.
The smooth and precise Celestron CGEM II go-to mount makes finding over 40,000of those stars and objects easy and automatic. You spend more time looking at celestialobjects, and less time looking for them. The CGEM II mountcombines portability and premium-level performance with a payload capacity of40 pounds. This makes for very steady imaging and visual observing with the 28pound 11” Celestron EdgeHD optical tube.
With a heaviest single component of only 44 pounds, the CGEM II 1100HD makeslarge-aperture astrographic-quality imaging and visual astronomy not onlyaffordable, but highly portable. Its light weight individual components andeasily assembled mount make it easy to set up and enjoy – either in your backyard or at a distant dark sky site. Its superb flat-field reduced-coma opticalquality and reasonable price for a really big full-featured computerized go-tomount make Celestron CGEM II 1100HD a telescope that will provide years ofaffordable use and enjoyment for both the serious observer and the dedicatedimager alike.
This Telescope’sOptical System . . .
·EdgeHDSchmidt-Cassegrain optical tube: 11” aperture (2800mm focal length f/10). Built-in dual-elementfield flattener in the central baffle tube. Guaranteed diffraction-limitedoptical performance, free from coma and corrected for spherical aberrations(aplanatic design). The optical design is a Sky & Telescope Hot Product for 2010. The 24” long aluminum optical tube has a large handle on therear cell and weighs only 28 pounds, making it easy to transport and assemblethe scope in the field.
·StarbrightXLT fully-multicoated optics: This high transmission/high reflectivity optical multicoatingspackage is applied to all optical surfaces. Starbright XLT coatings give youvisibly higher light transmission for visually brighter deep space images andshorter exposure times during imaging. They also increase the contrast onsubtle lunar, planetary, and nebula details when compared with a scope withordinary coatings or multicoatings.
·Tubevents: Two cooling ventslocated on the rear cell allow warm air to be released from behind the primarymirror when the scope is taken out for a night’s observing or imaging. Thisshortens the amount of time needed for the optics to cool down to ambient airtemperature for peak optical performance. Each vent has an integrated 60 micronmicro-mesh filter guaranteed to let warm air out without letting dust in.
·Fastarcompatible: For the ultimate inwide-field catadioptric imaging, the EdgeHD optical tube is Fastar compatibleto allow CCD imaging at a blazingly-fast f/2 focal ratio, although without thebenefits of the dual-element field flattener built into the scope’s baffletube. An optional Fastar lens assembly lens replaces the telescope’s removablesecondary mirror (an exchange that takes only a few minutes). Your CCD camerais attached to the Fastar lens. This puts your camera at the f/2 position inthe center of the Schmidt corrector lens at the front of the scope, rather thanin its normal f/10 position at the Cassegrain focus at the rear of the scope.
Using the Fastar system and a sub-$1500 Orion Star Shoot Deep Space Imager ProCCD camera, the 11” CGEM II 1100HD will record a wide 141 x 94 arc minute field– a long axis almost five times the diameter of the full moon, an immense fieldfor a scope of this size. To assure repeatability when you switch betweenFastar and conventional imaging, the scope’s optical tube is opto-mechanicallyaligned on a laser bench during manufacture so that all components are axiallysymmetric in any configuration.
·Focusing: Focusing is accomplished by turning a knob atthe rear of the scope body that moves the primary mirror fore and aft along acentral baffle tube to adjust the focus. The Celestron focusing mechanism issupported by two pre-loaded ball bearings, minimizing the “mirror flop” typicalof bushing focus mechanisms that causes image shift during critical focusing.
·Mirrorlocks: Flexible tension lockshold the mirror in place after correct focus is achieved for imaging and reduceimage shift when rotating the tube around the mount (while moving past thezenith during astrophotography, for example). Unlike other designs that haveonly one locking knob located off to one side of the mirror, the Celestronsystem uses three locks equally spaced around the mirror to distribute themirror locking force symmetrically. The focuser itself acts as one of thelocks, while two flexible rods spaced 120° away in either direction act as thesecond 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 placewithout putting any asymmetrical force or pressure on the mirror. This keepsthe image centered in the eyepiece (or chip) no matter what the orientation ofthe 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-adjustquick release bracket..
·Stardiagonal: 2” first-surfacemirror type, with 1.25” adapter.
·Eyepiece: premium 2” 23mm 82° field Axiom (122x), a muchhigher quality eyepiece than those supplied with competitive scopes. Theeyepiece field of view is 0.67° wide, a third wider than the full moon, and anexceptionally wide field for the 122x magnification.
This Telescope’s Mount. . .
·Heavyduty CGEM II computerized German equatorial mount: The CGEM II mount includes dual-axisslewing/tracking motors on each axis for go-to computer control. There are ninemotor drive speeds: 0.5x and 1x sidereal for guiding; 4x, 8x, 16x, and 64x forcentering; and 0.5°, 2°, and a fast 4° per second for slewing. Preset trackingrates include sidereal, solar, and lunar for precise tracking of celestialobjects inside the solar system as well as out in deep space.
·Poweringthe CGEM II 1100: Themount comes with a car battery cord to operate from the cigarette lighter plugof your car or from a rechargeable 12VDC battery pack. The 17 amp hour capacityCelestron Power Tank #4517V is recommended and will operate the scope all nightlong without danger of running out of power.
·Polaralignment: To make a casual polaralignment for visual use quick and easy, there’s a latitude scale with largeergonomically-friendly altitude and azimuth adjustment knobs. No polaralignment finderscope is available to aid in the precise polar alignmentrequired for long exposure astrophotography, nor is any needed. A uniqueCelestron All-Star Polar Alignment program built into theNexStar hand control helps you do a very precise computerized polar alignmentin mere minutes, using any bright star, even when Polaris is hidden by trees orbuildings. The program works in both northern and southern hemispheres.
·Adjustableheight tripod: The tripod has 2”diameter stainless steel legs with a metal center leg brace for rigidity, for excellentvibration damping characteristics. The tripod also includes graduated markingson the tripod legs that will assist in quickly leveling the instrument. The center leg brace is drilled to form aconvenient accessory tray that holds 1.25” and 2” eyepiece to keep them up outof the dew-soaked grass.
·Mountingthe scope: New for the CGEM IImount is a dual saddle plate. The saddleplate will now accept both the CGE/Losmandy wide dovetail plate as well as the AVX/Vixenstyle dovetail plate. The dovetail sloton the top of the mount holds the long dovetail slide bar mounted under theoptical tube. This allows you to slide the optical tube fore and aft in thedovetail slot to quickly and precisely balance the optical tube in declinationwhen you add or subtract accessories, eliminating the need for an extracounterweight to balance a camera or other accessories. Setup and takedowntimes are exceptionally fast, as a single large hand-tighten knob holds theoptical tube in place. A second lock knob prevents the tube from sliding offthe mount should the hand-tighten knob loosen. The oversized dovetail mountingplatform assures secure vibration-free tube attachment.
·Balancingthe scope: The two sliding 17pound counterweights are locked in place on the counterweight shaft with asingle large hand-tighten knob each. This makes it easy to rebalance the scopein right ascension if you add heavy photographic accessories.
· NexStar computer hand control: The supplied NexStar computer hand control hasa built-in database of more than 40,000 stars and objects that it can find andtrack for you. These include the complete RNGC, Messier, Caldwell, IC, andAbell catalogs; selected SAO stars; the planets, the Moon, and others. Thecustom database lists of all the most famous deep-sky objects by name andcatalog number; the most beautiful double, triple and quadruple stars; variablestars; non-planetary solar systems objects; and asterisms.
·TheNexStar display: Allof the database and scope operation information is displayed on a double line,16-character, liquid crystal display on the hand control. There are 19 fiberoptic backlit LED buttons to make it easy for you to control the computerwithout affecting your dark-adapted vision. The NexStar hand control provides aconstant and easily-visible illuminated right ascension and declination readoutof the scopes position on the sky. This provides much greater accuracy thanconventional (and hard to see at night) manual setting circles for star-hoppingor locating objects by their celestial coordinates alone, should you want toobserve the old-fashioned way without using the computer to find objects for you.
·SomeNexStar features: New for the CGEM II mount, a USB 2.0 communication port on the hand controlallows you to operate the telescope via a personal computer using a USB cableand NexRemote software CD-ROM. The hand control and motor control software isflash-upgradeable to allow you to download the latest product updates over theInternet to keep your CGEM II mount always at the cutting edge of technology.An autoguider port is located on the electronic pier for guided, butunattended, long exposure astrophotography.
·Aligningon the sky: Five differentalignment methods are built into the NexStar computer – 2-star align, quickalign, 1-star align, last alignment, and solar align – allowing you to choose alevel of computer accuracy in automatically finding objects with which you arecomfortable. Alignment is easily accomplished in only a few short minutes. Youcan be observing in less than 15 minutes after you first take the scopeoutdoors. There’s even a new and unique “All-Star” software-assisted alignmentof the mount’s polar axis using a single bright star that will have you readyfor imaging before it’s even dark enough to see the North Star.
· Two-year warranty: All Celestron go-to telescopes have a two-yearwarranty, double that of competitive go-to scopes.