Celestron 8\" RASA Rowe-Ackermann Schmidt Astrograph OTA For Sale
Celestron 8\" RASA Rowe-Ackermann Schmidt Astrograph OTA:
Celestron 8\" RASA Rowe-Ackermann Schmidt Astrograph OTA
Celestron RASA telescopes were designed for wide-field deep sky imaging and their 8\" format offers a highly portable astrograph that mounts easily to a wide variety of equatorial mounts for an affordable imaging system that is easy to take into the field. Rowe-Ackermann Schmidt Astrographs are in remarkably fast telescope designs as well at just f/2.0 exposure times are dramatically cut down while catering to modern CMOS and smaller CCD imaging cameras along with mirrorless cameras. Sony\'s A7 series and the ATIK Infinity cameras are a favorite paring with these astrographs. The combined short focal length and patented optical design help to produce tack sharp images with high detail and, often, allow you to image without an autoguider altogether. The 8\" RASA is just 17 pounds making it easy to lift and setup by a single person.
Celestron RASA is an imaging telescope series 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.
Please be aware. 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.
Because shorter exposure times are possible, your equatorial mount won’t need to accurately track over extended periods. The 8” RASA’s relatively short 400mm focal length also lessens equatorial tracking demands. In many cases, autoguiding will not be required. Weighing only 17 lb, this optical tube pairs perfectly with a wide variety of mounts.
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 Today’s 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. The telescope does not work with standard DSLR cameras. It is optimized for sensors with up to a 22mm diagonal, but performs well with sensors up to 32mm diagonal. The APS-C sized sensors used in many mirrorless cameras are a good choice. 42mm full frame sensors will also work, but performance will be poor at the edges of the sensor and field illumination will be reduced. Additionally, we do not recommend pairing RASA 8 with any camera body more than 4” in diameter. See the chart below to determine if your camera is compatible with RASA 8.