Celestron 8" RASA Optical Tube Assembly (CGE Dovetail)

Celestron 8" RASA Optical Tube Assembly (CGE Dovetail)

Capture Stunning Wide-Field Deep Sky Images Instantly

Take breathtaking wide-field astrophotography shots in moments with Celestron’s portable Rowe-Ackermann Schmidt Astrograph (RASA) 8”. This ultra-fast f/2.0 system is ideally suited for today’s color CMOS astronomy cameras, compact CCD cameras, and mirrorless models. Thanks to its lightning-fast focal ratio and innovative optical design, the scope produces crisp, detailed images and often allows you to image without needing an autoguider. Weighing only 17 lbs, the 8” RASA is easy to carry to remote dark-sky locations.

RASA Performance for Every Imager

The RASA 8” is an imaging telescope that delivers a flat, coma-free field with pinpoint stars across a wide view. It makes capturing stunning deep-sky shots far simpler than long focal length scopes and does so at a fraction of the cost.

As the newest member of the RASA family, this 8” version offers a lighter, more budget-friendly option compared to the acclaimed RASA 11, first introduced in 2014. With this compact model, more astrophotographers can now access the advantages of RASA’s design. It includes many of the same key features as the larger 11” version-such as an integrated cooling fan, built-in filter holder, and durable CGE dovetail bar.

This telescope is designed solely for imaging-not for visual observing. Its prime focus imaging plane sits at the front of the system, making it incompatible with standard eyepieces.

Shorter Exposure Times and Virtual “Real-Time” Observing

With its f/2.0 optical speed, the RASA 8 enables shorter exposures to reveal details in faint objects. Combined with sensitive cameras and live-stacking software, the system provides an almost real-time astronomy experience. Images appear instantly on your computer-brighter and more detailed than what can be seen visually through much larger scopes.

Since exposures are shorter, your equatorial mount won’t require ultra-precise long-term tracking. The relatively short 400mm focal length also reduces tracking demands, meaning autoguiding is often unnecessary. At just 17 lbs, the RASA 8 pairs well with a broad range of mounts.

Ultra-Stable Focusing Mechanism

With the launch of the RASA 8, Celestron introduced a new focusing system to reduce image shift when adjusting focus, slewing, or tracking. The Ultra-Stable Focus System uses a precision linear ball bearing, tested individually during assembly for maximum performance. This makes focusing smoother, more reliable, and far more stable than before.

Optimized for Modern Imaging Cameras

While larger RASA models accommodate DSLRs and full-frame CCDs, the 8” version is specially optimized for color CMOS astronomy cameras, smaller CCDs, and mirrorless cameras. It is not compatible with standard DSLR bodies.

The RASA 8 is best matched with sensors up to 22mm diagonal, though it also performs well with sensors up to 32mm diagonal. Popular APS-C mirrorless sensors are an excellent choice. Full-frame 42mm sensors will function, but expect vignetting and reduced performance near the field edges. Additionally, Celestron advises against using camera bodies wider than 4 inches in diameter.