Hi, I own the exact combo you are considering -- RASA 8 + AVX.
First the simple part. AVX is awesome for EAA purposes with RASA 8. It is light and gets the job done. It is my go to. You will need 3 after market changes to the AVX to get the most out of it.
1. With RASA 8, you will need the additional Orion 7.5 - 8 lb weight UNLESS it was purchased as a combo and the extra weight is included.
2. The Starizona bubble just sticks to the front of it and helps you quickly get the AVX roughly level
3. And the most crucial part -- replace the OEM saddle with the ADM dual saddle. The OEM saddle is terrible... ADM dual saddle is a first class upgrade from center seat economy
Now the slightly more complicated part:
1. check the CCD suitability tool (and the FOV tool) on astronomy.tools. As Steve points out above, 294 under samples for RASA 8 substantially, and this will not be good especially in a Bortle 5 type setting -- I found it problematic even in Bortle 7/8.
Given the amount of data RASA can quickly collect - with current CMOS camera options, you are left with three choices to achieve different results:
The best resolution (which will be fine for "average" seeing and almost adequate for "good seeing") comes from something like ZWO 183 MC Pro. I use this to focus on single objects or clusters that are roughly up to 70 arc minutes. Compare the 183 with the 294 and you will see what i mean -- 183 gives you roughly 1.24 arc seconds per pixel, where as 294 gives you roughly 2.4 arc seconds per pixel. ZWO 533 MC Pro and 2600 MC Pro give you about 1.94 arc seconds per pixel.
Quite simply, the 183 MC Pro is hands down the best camera for RASA 8 for single objects where you want to focus on details. Do a search here and look for a view I captured of the Rosette -- you would think it was in an advanced astrophotography forum
You will enjoy it all the way down to an object size of about 5 arc minutes, a bit smaller when seeing is better.
Go the other direction - looking for wide field stunning views -- say M31 and M32 in their full glory together -- you are looking for something like the 2600 MC Pro as the ideal camera. It is very hard to match the image scale and quality of views you can capture.. both the 533 and 2600 have very little amp glow.
Finally the most complicated part -- is the RASA 8 worth it?
If you are looking for a very fast high quality light bucket you can use for EAA, albeit with a limitation on the resolution, very hard to beat RASA 8.
At the same time, its not for the casual observer who is starting out in the EAA hobby. You need darks and flats to get the very best results with the RASA (not hard to do at all), you will need to tinker to optimize your workflow and results.
If one was getting a RASA as a bucket list item and could accept a higher weight (using a backyard observatory for example), I would get a RASA 11 in a heart beat. All those concerns about being limited due to resolution go away. You also get ample backfocus to set up your optical train perfectly.
RASA 8 is a compromise solution by comparison. It is quite portable and a lot of fun. In exchange you accept the resolution limit (1.24 arc seconds per pixel is the best current technology can do) and limits on optical train accessories. You dont need much accessories to have fun for EAA.
Yes the Artesky or Starizona drawer or PreciseParts custom adapter all can help you tune the optical set up, add filters etc. At Bortle 5, i am not sure the RASA will need any filters other than Nebula filter for max effect. I use the Triad Quad and it is mindblowing for Nebulas given how much data the RASA can quickly collect.
You will not need a finder of any kind with RASA Just plate solve in a second or two, done! But yes if you really need to for whatever reason, you can install one.
Accessories I would recommend with RASA -- a light box for proper flats, a filter adapter, and the Celestron focus motor. Search this forum for tips I had posted on how to set up the Celestron focus motor correctly on RASA 8.
Software -- Sharpcap Pro, Carte Du Ciel (free) for planetarium, and CPWI (Celestron, free).
Good luck, and happy to address any other questions you have.
Edited by SanjeevJoshi, 21 July 2021 - 08:45 PM.