Celestron RASA 8" Rowe-Ackermann Schmidt Astrograph OTA

Capture spectacular wide-field deep-sky images in seconds with the Celestron 8" Rowe-Ackermann Schmidt Astrograph (RASA), a high-performance astrograph engineered for fast, detailed astrophotography. With an exceptionally fast f/2.0 optical system, the RASA 8 is designed to pair beautifully with modern astronomical cameras, including color CMOS, smaller CCD, and mirrorless camera systems. Its patented optical design and fast focal ratio enable efficient imaging while maintaining sharp, detailed results. The system's impressive imaging speed can also allow astrophotographers to capture targets without relying on an autoguider in many situations, simplifying the overall imaging setup. Despite its advanced optical performance, the 8" RASA remains remarkably portable. Weighing just 17 pounds, it can be transported to remote dark-sky locations, giving astrophotographers the freedom to pursue exceptional imaging conditions without the bulk of a larger astrograph.

RASA Performance Made for Everyone

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. 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 unveiled a 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 a precision linear ball bearing, which is 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.

Features

• Flat field free of optical aberrations like field curvature, coma, astigmatism and chromatic aberration across an entire APS-C sensor.
• 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.
• Ultra-Stable Focus System – precision linear ball bearing virtually eliminates image shift.
• Integrated air cooling system –12V DC MagLev fan reduces cooldown time and provides optimal air flow while filtering out dust.
• Internal filter mount – seamlessly accommodates a Light Pollution Imaging Filter into the optical path.
• CGE dovetail mounting rail.
• Performs over a wider spectral range than most telescopes, from 400nm – 800nm, so more of the light passing through the astrograph is in sharp focus.