I have been at the lookout for a wide field scope (what some people call astrographs) and this spring I came across a nearly unused RASA8, and after 6 months waiting time, due to the virus situation, I finally received an ASI2600MC - an APS-C sized cooled OSC with relatively small pixels (3.76 µm) that kind of fit the 400 mm FL of the RASA8 (ca 2 "/pix sampling). As I allready had my two obsies filled up with other scopes I decided to spend the summer building a third obsy for the RASA to put on my long-time retired NEQ6, my first mount bought in 2014 when I started my AP adventure, but having been laying in a closet for the last five years, beeing replaced by an EQ8 and a Mesu in my other obsies.

Up here astrodarkness started a few days ago, and on Saturday I could finally get the first light out of the RASA and ASI2600. I though I would go for something simple, at least something I could easily find with the NEQ6 and hand controller: M31.

I have to say I am very impressed with both the scope and camera. The collimation of the RASA was spot on (round defocused stars) and it maintained focus all night, although all night here is now only three hours. I am equally impressed with this new ASI camera. As promised there is no amp glow so no need for darks. There was also virually no vignetting by the RASA8 although it is stated to perform best up to an image circle of 22mm. The diagonal of the ASI2600 is 28mm. However, the stars in the corners were a bit elongated, probaly due to minor tilt, but trying to fix that on an f/2 telescope could be quite challenging and it will at least not be my first priority. Andromeda fitted with margin so I could crop away the edges.

I don't think anything I have set up to do in AP has been as smooth as this. Fortunately I fouund that Baader make a 7.5 mm T2 extension witch is what is exactly needed to fit the ASI2600 to the T2 adapter of the RASA to get to the 29 mm chip distance. The ASICAP program I use for my older ASI cameras did not work with the 2600 but I soon found out that there is a new ASICAP hidden within the new bundle called ASIStudio. Focus was easy and it kept all night - I have heard that about the RASA before (like on Chuck's Astrophotography on Youtube).

So my conclusion is that the RASA8, even being an f/2 scope, which is supposed to be extremely tricky to use, is very easy to get working. I think that bad rumour may come from the Hyperstar attachement that you can fit to SCT scopes, but the RASA is dedicated to this and apparently hardly ever needs collimation.

My only complaint so far are the star shapes that may not impress pixel peepers (including me) but I think I can improve on them by organizing the two cables to the camera in a curved form - I am trying that out tonight on M33.

So, enough rambling about the RASA, here are my first 90 minutes (180 x 30 seconds at gain 100) aquired with the RASA8 and ASI2600. No flats (I did take some but it looked better without) and no darks (not needed with the ASI2600). Stacked in PI and processed in PS. I also tried 70 x 60 seconds at gain 0, and it looked similar but not really as good.

I should make a thread on SGL about the obsy build - I had to go to plan C before it worked out.