What kind of detail can the 11" RASA resolve on the Andromeda Galaxy (M31)?
With its 620mm focal length, the Celestron CGX-L 11" RASA can frame the entire Andromeda Galaxy (M31) with room to spare, even on an APS-C sensor. The 279mm aperture and 0.41 arc-second Dawes limit allow you to resolve individual star-forming regions, intricate dust lanes, and even globular clusters within M31's spiral arms, all while capturing the faint outer halo in significantly shorter exposures than a conventional telescope.
How does the CGX-L mount handle the 43 lb RASA OTA for long exposures of the Orion Nebula (M42)?
The CGX-L's 75 lb instrument capacity easily manages the 43 lb RASA optical tube. The large 144mm worm wheels and DC servo motors provide the smooth, precise tracking necessary for sharp stars. For a bright target like the Orion Nebula (M42), the RASA's f/2.2 speed allows for very short sub-exposures, further reducing demands on the mount and often eliminating the need for autoguiding entirely.
What cameras are compatible with the RASA 11's 55mm back focus?
The RASA 11 is designed with a 55mm back focus when using the included M42 (T-thread) or M48 camera adapters. This is the standard spacing for most DSLRs with their T-rings and many dedicated astronomy cameras. You simply need to ensure your camera body and any accessories (like filter drawers) fit within that 55mm distance from the adapter's threads.
Is autoguiding necessary with the f/2.2 RASA system?
Often, it is not. Because the RASA 11 requires such short sub-exposures (e.g., 30-60 seconds instead of 5-10 minutes), minor periodic error from the mount is less likely to cause star trailing. For many imagers using the robust CGX-L mount, unguided imaging is entirely feasible, which greatly simplifies the imaging setup.
Can I use the RASA 11 for visual observing or planetary imaging?
No, the RASA is a dedicated photographic instrument. There is no place to insert an eyepiece, and the optical design with its 41% central obstruction is optimized for wide-field, deep-sky imaging, not the high-magnification views required for planets. It is purpose-built as a high-speed astrograph.
What is the benefit of the CGX-L's 144mm worm wheels?
A larger worm wheel provides finer control over the telescope's movement. The 144mm diameter wheel on the CGX-L has more teeth than a smaller wheel, resulting in lower periodic error and smoother, more accurate tracking. This is especially critical when carrying heavy payloads like the 11" RASA and a full camera package.
