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Celestron - C11S-GT Advanced Series with STARBRIGHT XLT Coatings
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$ 2279.00
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Click here for recommended accessories |
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If you’re looking for a large aperture telescope for a phenomenal value, consider the C11-S
telescope. The largest aperture Advanced telescope in the series, this new 11” Schmidt-Cassegrain
optical system is mounted on the CG-5 EQ mount, which features precision worm gears for extremely
smooth motion. And with the heaviest component under 30 lbs this telescope won’t break your bank
or your back. Equipped with 2” steel legs, this heavy duty mount delivers jitter-free images.
With adjustable height, the very rigid tripod has excellent damping characteristics and a
convenient metal accessory tray/leg brace for added strength. Included are setting circles on
both axes, slow-motion controls and latitude scale. Adjustable counterweights makes it easy to
point, balance and use. The C11-S optical system comes with StarBright® coatings and its large
aperture offers light gathering power 1593 times that of the human eye and 89% more than our 8”
model. An optional polar alignment scope for quick alignment as well as a motor drive is
available for easy tracking for all CG-5 mounted telescopes.
C11S-GT - Includes:
* 11” Schmidt-Cassegrain
* 2800mm Focal Length, f/10
* StarBright Multi-Coatings or optional Starbright XLT Coatings
* Adjustable 2” Steel Leg Tripod with Accessory Tray/Leg Brace
* Right Ascension and Declination Setting Circles
* Slow Motion Control Knobs on Both Axes
* 1-1/4” 40mm Plössl Eyepiece (70x)
* 9x50 Finderscope and Mounting Bracket
* CG-5 Equatorial Mount and Tripod
* Three 11# Counterweights
* Star Diagonal - 1-1/4”
* The Sky Level I CD-ROM
* Accessory Tray
* Telescope Weight: 91 lbs
* Duel-Axis slew motors,
* Computerized Hand Control with 40,000+ objects database,
* Car battery adapter
Celestron has brought its renowned StarBright technology to an even higher level of light
transmission with the introduction of our new optional StarBright XLT High Performance Optical
Coating System.
StarBright XLT Optical System Design - You’ll See The Light.
One of the most important factors in the evaluation of a Schmidt-Cassegrain telescope’s optical
system performance is its transmission - the percentage of incoming light that reaches the focal
plane. The design of the XLT System accomplishes two crucial objectives: Develop a coating system
that is optimized for visual use and for CCD/Photographic imaging.
The StarBright XLT System - What Makes It Different Makes It Better
There are three major components that make up our StarBright XLT high transmission optical system
design:
1. Unique enhanced multi-layer mirror coatings
Our mirror coatings are made from precise layers of Aluminum (Al), SiO2 (quartz), TiO2 (Titanium
Dioxide), and Si02. Reflectivity is fairly flat across the spectrum, optimizing it for both CCD
imaging and visual use. Click here to see a plot of the reflectivity of XLT’s Mirror Coatings.
2. Multi-layer anti-reflective coatings
Made from precise layers of MgF2 (Magnesium Fluoride), and HfO2 (Hafnium Dioxide) A rare element
costing nearly $2000 per kilogram, Hafnium gives us a wider band pass than Titanium, used in
competing coatings. Click here to see a plot of XLT’s corrector transmission.
3. High Transmission Water White glass
Celestron Schmidt-Cassegrain optical systems with optional StarBright XLT coatings use Water
White glass instead of Soda Lime glass for the corrector lens. Water White glass transmits about
90.5% without anti-reflective coatings. That is 3.5% better transmission than uncoated Soda Lime
glass. When Water White glass is used in conjunction with StarBright XLT’s anti-reflective
coatings, the average transmission reaches 97.4% - an 8% improvement! Click here to see a plot of
water white glass versus soda lime.*
These three components of our StarBright XLT coatings result in one of the finest coatings
available. The peak transmission for the systems is 89% at 520 nm. The overall system
transmission is 83.5% averaged over the spectrum from 400 to 750 nm.
Recognized For Superior Stability
An improved Super HD Tripod supports the
CGE mount. This fully extendable tripod is made from the finest cold rolled carbon steel and can
be raised to a height of 50”. 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. CGE Equatorial Mounts Can Easily be Balanced on Both
Axes
Balancing the weight of camera equipment and other visual accessories is
accomplished by simply sliding the counterweight for Right Ascension and moving the optical tube
along its dovetail mounting for Declination. This means that no additional weight needs to be
added to balance the telescope when additional accessories are added. Clearance For
Accessories
CGE mounts support their tubes at a single contact point allowing the tube
to move freely around its polar axis without making contact with the telescope’s mount. This is
particularly useful when adding photographic and CCD instruments that extend from the rear of the
telescopes. GPS Compatible
All CGE mounts are compatible with
Celestron’s CN16 GPS accessory (Item #93967). Combine the GPS and built-in Hibernate mode and
these mounts will keep track and remember their exact location and time without the need to
re-enter the information into the remote hand control.
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