Celestron Telescope RASA CGEM II 800, f/2.0

This kit combines the 8 Rowe-Ackermann Schmidt Astrograph (RASA) with the CGEM II EQ mount. Simply add a camera and this package offers everything you need to take spectacular images of wide-field deep sky objects. RASA Performance Made for Everyone Capture spectacular wide-field deep sky images in seconds with Celestrons new portable astrograph, the 8 Rowe-Ackermann Schmidt Astrograph (RASA). This incredibly fast f/2.0 system is the perfect companion to todays color astronomical CMOS cameras, smaller CCD cameras, and mirrorless cameras. Thanks to its fast focal ratio and patented optical design, you can produce sharp, detailed images and, in many cases, skip the autoguider completely. Weighing in at just 17 pounds, its easy to transport your 8 RASA to the most remote dark sky locations. The 8 RASA is an imaging telescope that delivers a flat field without optical aberrations for razor sharp stars across a wide field of view. It can capture stunning deep-sky astronomical images without the challenges typically presented by longer focal length instruments at a fraction of the cost of those systems. The latest addition to the RASA family, this 8 version is a much more portable and affordable version of the heralded RASA 11, which was introduced to much acclaim in 2014. With the 8 RASA joining the lineup, a wider range of astroimagers can enjoy the benefits of the RASA design. It has many of the same thoughtfully designed features as its big brother RASA 11, including the integrated air-cooling system, internal filter mount, and sturdy CGE dovetail mounting bar. Purely designed for imaging, the 8 RASA cannot be used visually. The prime focus focal plane is located at the front of the optical system, so it cannot accommodate a traditional eyepiece. Shorter Exposure Times and Virtual Real-Time Observing Since it is an F/2.0 optical system, imagers can use shorter exposure times to capture detail in faint objects. When combined with sensitive cameras and the proper live stacking software, the 8 RASA can provide an almost real-time observing experience. View images on a computer instantly that are brighter and more detailed than can be seen in much bigger telescopes with the naked eye. Ultra-Stable Focus System With the launch of the 8 RASA, Celestron is unveiling a new focuser design that mitigates lateral movement of the primary mirror when focusing, slewing, or tracking with the astrograph. Focusing is easier, more accurate, and more stable than ever. The key to the Ultra-Stable Focus System is two sets of precision bearings that are precisely aligned and tested during assembly to ensure optimal results. Built for Todays Latest Cameras Unlike the larger RASAs that work with DSLR and large CCD cameras, the 8 model was designed with color astronomical CMOS cameras, smaller CCD cameras, and mirrorless cameras in mind. It is optimized for sensors with up to a 22mm diagonal, but still performs well with larger (up to 32mm diagonal) sensors. As such, it works well with APS-C sized sensors used in many mirrorless cameras. Camera adapters to connect C-mount cameras and cameras that mount with M42 threads are included. Celestron offers optional adapters to connect your 8 RASA to Sony or Canon mirrorless cameras. Unique Optical Design RASAs optical design is patented (US 2016/0299331 A1). The design consists of a Schmidt corrector, primary mirror, lens group, and optical window. The lens group contains 4 elements and utilizes rare-earth elements. Unlike many telescopes that only perform well over the visible spectrum (400-700nm), the 8 RASAs optics are designed to perform over a wider spectral range, from 390-800nm. This allows more of the light emitted from the astronomical object to be sharply focused in the image. With many imaging systems, adding an extra piece of flat glass such as a filter does not change optical performance. However, that is not the case with super-fast optical systems like the RASA. Our engineers addressed this by designing the RASA with a removeable optical window, so you can maintain peak optical performance if a filter is added or if a camera has its own optical window. Celestron offers a Light Pollution Imaging Filter designed specifically for the 8 RASA, which mounts in place of the optical window. All refractive optical surfaces are coated with StarBright XLT coatings, while the primary mirror uses enhanced aluminum coatings. This maintains high light transmission through the entire optical system. When compared with Hyperstar SCT systems, the RASA 8 provides better optical performance and field illumination. CGEM II: An Excellent Platform for RASA CGEM II is a sturdy equatorial mount capable of rigidly supporting the 8 RASA. Its 40-lb. load capacity can handle the 17-lb. optical tube with ease, leaving lots of capacity to spare for your camera and any accessories. The heavy-duty adjustable height tripod has 2 diameter steel tripod legs with graduated markings that make it easy to extend the legs to the same height. The 8 RASA connects directly to the CGEM II with its CGE dovetail mounting bar. The mount is packed with functionality and conveniences that make imaging with the 8 RASA easy. The fully computerized mount will automatically GoTo any of the 40,000+ astronomical objects selected from the NexStar+ hand controllers database and automatically track the object as it appears to move across the night sky. Designed with imaging in mind, the CGEM II motor drive system accurately tracks during an exposure. At the heart of the system are low cog DC servo motors with integrated optical encoders. The low cog design helps the motors run smoothly, while the integrated optical encoders provide accuracy. The motors turn steel worm gears, which are supported by precision bearings, against brass worm wheels. These components also help to make the motor drive system operate smoothly and accurately. To track objects in the night sky, the mount must first be polar-aligned. Celestron makes this process easier than ever with the innovative All-Star Polar Alignment procedure. No extra equipment, such as a polar finder scope, is required. (An optional polar alignment finder scope is available if desired.) Best of all, the alignment can usually be completed in about 15 minutes, even without a clear view of Polaris. All mounts have some amount of periodic tracking error inherent in them caused by tiny gear imperfections. To mitigate this, the CGEM II has Permanent Periodic Error Correction (PPEC). This allows you to run a routine to record the periodic errors only once; the recording is kept in memory, and subsequently corrects for the mounts periodic tracking error. If an even higher level of tracking accuracy is desired, the CGEM II also has a dedicated autoguider port to connect an autoguiding camera directly to the mount to correct for any residual tracking errors. Conditions for imaging are best when celestial objects are at their highest point in the sky with the darkest background, called the meridian. But some German equatorial mounts have trouble tracking near the meridian because they need to perform a meridian flip, readjusting their position to avoid the tube striking the mount. CGEM II does not suffer from this problem, imaging through the meridian with ease and not requiring a meridian flip until the object is a full 20degree past the meridian. The NexStar+ also has dozens of other functions to control every aspect of the mounts behavior. These include: Multiple ways to align the mount to the night sky Adjustable slew rates up to 5 degree/second Northern or Southern hemisphere compatibility Adjustable autoguiding rates Hibernate mode so the mount can be powered down without loss of alignment Continual firmware development, with new features added regularly In addition to the autoguider port, the CGEM II also has other ports to enhance and expand the capabilities of the mount. The hand controller has a USB 2.0 port for those who wish to control the mount with an external computer and optional third-party software. There is an AUX port on the mount that can support optional accessories such as StarSense AutoAlign. When imaging, cable management can be a problem. The camera has a cable, the mounts power source has a cable, and additional cables can come from a computer connection and augtoguider. To minimize cable management issues and prevent unwanted snags, all cabling for the mount is housed internally. This also eliminates the need to connect or disconnect an external Dec. motor cable when the mount is set up or broken down. Transporting the entire system to a dark site is not a problem either. The optical tube, mount head, tripod, counterweight bar, and counterweight all disassemble, with no tools required, into separate manageable pieces. In summary, the CGEM II and RASA 8 work well together to attain stunning imaging results with minimal hassle. Its the perfect kit for those who want to take the next step into deep-sky astroimaging. Specifications for Celestron Telescope RASA CGEM II 800, f/2.0: Manufacturer: Celestron Focal Ratio: f/2.0 Color: White Finderscope: Not Included Optical Coating: StarBright XLT Features of Celestron Telescope RASA CGEM II 800, f/2.0: Flat field free of optical aberrations like field curvature coma astigmatism and chromatic aberration across an entire APS-C sensor. NEW Ultra-Stable Focus System six precision sealed ball bearings virtually eliminate image shift. Internal filter mount seamlessly accommodates a Light Pollution Imaging Filter into the optical path. Performs over a wider spectral range than most telescopes from 390-800 nm so more of the light passing through the astrograph is in sharp focus. The CGEM II with its 40 lb load capacity is the latest update to the venerable CGEM mount and provides a sturdy and rigid platform for the fully-loaded RASA 8. The drive system consisting of low cog DC Servo motors with integrated optical encoders steel worm gears supported by precision sealed bearings and brass worm wheels ensures smooth and accurate slewing and tracking. Proven NexStar+ computerized telescope control technology supports functions to address imagers needs such as All-Star Polar Alignment Permanent Periodic Error Correction (PPEC) and adjustable tracking through meridian. Optical Design: Rowe-Ackermann Schmidt Astrograph Aperture: 203mm (8″) Focal Length: 400mm (15.74″) Focal Ratio: f/2.0 Central obstruction diameter: 93mm (3.66″) (46% of aperture diameter) Light Gathering Power (Compared to human eye): 843x Resolution (Rayleigh): 0.68 arc seconds Resolution (Dawes): 0.57 arc seconds Image Circle: 22mm (.86″) 3.15degree Useable field: 32mm (1.26″) 4.6degree only minimal performance loss at edge of FOV Wavelength range: 390 – 800 nm Spot size: Included Accessories: CGEM II Equatorial Hea Tripod Accessory Tray 1 x 17 lbs counterweight NexStar+ Hand Control DC Power Cable (plugs into cigarette lighter socket) 8 mm Allen wrench (contained in rear carry handle). Package Contents: Celestron Telescope RASA CGEM II 800, f/2.0