Celestron CGEM II 800 RASA - 8" Rowe-Ackermann Schmidt Astrograph on CGEM II Computerized Equatorial Mount
Check Out This High Performance Celestron CGEM II 800 RASA Computerized Telescope!
The highly regarded Celestron 8” Rowe-Ackerman Schmidt (RASA) delivers stunning, bright images, and when paired with the high performance CGEM II, this system is sure to impress! The RASA features an incredibly fast focal ratio of f/2 and its wide field of view captures immense clouds of nebulosity in a single frame. Premier glass fitted within this high caliber OTA eradicates coma and aberration for images with beautiful clarity. Thanks to the innovative craftsmanship from Celestron, take your astrophotography to new heights!
A telescope of this caliber needs a just as impressive system in place to maximize its abilities. As such, Celestron has chosen their renowned CGEM II for the job! This robust equatorial mount tracks the night sky smoothly and with great accuracy thanks to its high torque motors. The large payload capacity of 40lbs effortlessly carries this 17lb RASA, with everything resting atop a sturdy tripod with 2” stainless steel legs. Enjoy operating this setup through the multiple means of control that are available, and have fun adding user supplied accessories to elevate the experience even further!
The Unmatched Optical Design of the Celestron RASA
Celestron has built upon the design of the famed Schmidt-Cassegrain telescopes to bring an OTA that pushes the limits of amateur astrophotography. This patented Rowe-Ackerman Schmidt Astrograph design consists of a Schmidt corrector, primary mirror, lens group, and optical window. Coma, field curvature, and false color are eliminated thanks to the four element rare-earth glass utilized within this system. Vignetting is also significantly minimized for heightened field illumination. As opposed to typical f/10 systems, the Rowe-Ackerman Schmidt Astrographs feature an outstanding f/2 focal ratio for wickedly fast imaging. This lower focal ratio means much more signal is collected in less amount of time for brighter, more detailed images while upholding image resolution. The RASA is 20x as fast as an f/10 SCT. To put this into perspective, a 30 second exposure with the RASA is equivalent in brightness to an exposure of 10 minutes with an f/10 system! A shorter focal length of 400mm is featured within this 8” RASA, giving you the ability to capture vast regions of the night sky. The wider field of view and speedy focal ratio are less demanding on the telescope mount, and autoguiding may not even be necessary in some situations. The improved 390nm to 800nm spectral range of the Rowe-Ackerman Schmidt Astrographs delivers greater collection of signal from celestial bodies as opposed to the 400nm to 700nm spectral range typical with other telescopes. The refracting elements of this RASA come furnished with the patented Celestron StarBright XLT coatings, and enhanced aluminum coatings can be found on the primary mirror. These additions greatly improve light transmission for even better performance.
Preserving image stability during image capture is necessary for the best astroimages possible. That’s why Celestron has fitted the RASA OTAs with an internal focuser and built-in fan. The Ultra-Stable Focus System (USFS) includes precision linear ball bearings for reduced image shift while focusing. This helps you achieve the best possible focus for sharp and clear images. Also, this reduces the effects of mirror flop, the unwanted primary mirror movement during different telescope pointing positions. Temperature equilibrium is also an important factor to consider when imaging. If the internals elements of telescope are a different temperature than its surroundings, currents will form within the tube, causing less than ideal image quality. The 12V DC MagLev fan helps this RASA quickly reach temperature equilibrium with its external surroundings and provides dust filtered airflow through the optical tube. These carefully engineered additions aid in delivering peak performance for images brimming with clarity!
Expand the Possibilities of Amatuer Astrophotography With This Celestron Computerized Telescope!
This CGEM II 800 RASA delivers high quality images and precise tracking abilities. After attaching your camera, you have yourself the perfect backyard astroimaging system! Accessories of your choice can be added to enhance your experience, making this a versatile set up for any astroimaging session. Read more about this Celestron Computerized Telescope below!
Effortless Camera Attachment
Rowe-Ackerman Schmidt Astrographs are designed solely for astrophotography purposes, and cannot be used visually. When it comes to camera attachment, this 8” RASA is optimized for sensors with a 22mm diagonal. APS-C sized color CMOS cameras, smaller CCD cameras, and mirrorless cameras are suitable options to pair with this OTA. DSLRs are incompatible with the RASA 8, and camera bodies larger than 4” are not recommended as field illumination decreases with increased camera size. To assist you in camera connections, this RASA 8 comes complete with a M42 adapter and C-thread adapter. The M42 adapter offers use with the majority of cameras with a standard T-thread, and requires 25mm of back spacing. Please note that the addition of user supplied M42 extension rings may be necessary. For instance, if your camera has a back focal distance of 17.5mm, you will then need an added 7.5mm of M42 spacers to reach proper focus. If the C-thread adapter and your camera meet the C-thread standard of 17.5mm of back focus, no additional spacers are needed to reach proper focus. When ready to affix your camera to this RASA 8, a few simple steps ensue: (1) Place the included knurled retaining ring over the appropriate camera adapter, then loosely thread it onto the front housing of the RASA; (2) next, thread your camera onto the adapter; and (3) finish threading in the retaining ring to secure everything in place, ensuring that you are not over-tightening as to prevent damage to the telescope. Now you’re all set to image! This retaining ring can be loosened and retightened to allow for camera rotation as well.
A Steadfast, High Payload Telescope Mount
The high payload capacity and robust internal mechanics make the CGEM II an ideal choice to haul this 8” RASA. This Celestron equatorial mount can be loaded with up to 40lbs of equipment, and effortlessly carries this 17lb telescope thanks to its high torque motors. These low cog DC Servo motors feature built-in optical encoders and provide smooth and quiet tracking across the night sky. Ergonomics such as longer clutch levers make loosening and tightening the axes much easier and internal cabling in both RA and DEC helps reduce dreaded cable snags. This CGEM II also allows you to track past the meridian, letting you capitalize on the most ideal portion of the night sky. The strong, sturdy tripod features 2" stainless steel legs for maximum stability, and comes equipped with a spreader bar that doubles an accessory tray. Also, two AUX ports and an autoguider port make it easy to add extra devices to your setup! Coming standard with powerful software from Celestron, fully ASCOM compliant, and equipped with the NexStar+ hand controller, find the method of operation that's right for you!
Included NexStar+ Hand Controller
Celestron has fitted this CGEM II 800 RASA Computerized Telescope with their powerful NexStar+ hand controller. This device has been programmed with over 40,000 objects within its database, and allows the addition of 100 user-defined objects as well! Not sure what you want to observe? This hand controller is equipped with a Sky Tour feature that shows you the most popular objects for the time and location you are observing. The red backlit Liquid Crystal Display (LCD) screen is clear and easy to read, and nineteen large backlit buttons make navigating through the controls effortless. In addition, this hand controller has a mini-USB port for connection to a PC for computer control.Please note: Celestron does not include a USB cable with their hand controller. We recommend the Apertura USB 2.0 Cable for Celestron NexStar+ Hand Controllers.
Optimized for Backyard Observing
Looking for the perfect backyard telescope setup? This CGEM II 800 RASA is the ideal option! The CGEM II features a heavy duty build of a 40lb mount head, 20lb tripod, and 17lb counterweight, providing incredible stability for this 8” RASA. Also, the option to control this telescope mount with a wide range of software means you can easily remote into your backyard rig from the comfort of your living room! The innovative internal cabling helps reduce the chances of cable snares throughout your night of imaging, giving you more peace of mind when away from your setup. With features like these, the CGEM II 800 RASA earns our High Point Scientific badge Backyard Observing!
Upgrade Your Experience with a Myriad of Accessories!
On the body of this CGEM II, you’ll find two AUX ports. While one of these AUX ports is meant for connection with the hand controller, the additional AUX port allows attachment of user supplied accessories! Make aligning with the night sky much easier through the Celestron StarSense AutoAlign, or even add Wi-Fi capabilities with the SkyPortal WiFi Module. The Celestron Focus Motor makes focusing a breeze, as it lets you focus with the hand controller for smooth, hands-free focusing. Even light pollution is a non-issue with the addition of the RASA 8 Light Pollution Imaging Filter from Celestron. Connect the StarSense Autoguider to this CGEM II for improved tracking and even sharper astroimages! With this multitude of accessories and upgrades, outgrowing your Celestron CGEM II 800 RASA computerized telescope is a thing of the past.
Astronomy Hub: Your one-stop-shop for Astrophotography Knowledge!
Our Gear Experts have compiled a wealth of information to help expand your astrophotography knowledge! Below you’ll find links to articles, videos and "how-to" guides. Just one more reason that our Astronomy Hub is a one-stop-shop for all your astronomy and astrophotography needs!
| Choosing the Best Deep Sky Camera |
| 10 Things You Need to Know About Nebulae |
| How to Balance Your Equatorial Mount |
| Autoguiding |
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