[The_bluester (Paul)]

I think that h0ughy's images there have some of the best looking stars I have seen out of a RASA 8, which proves that it can be done. The trick is that at F2 getting sensor tilt dialled in and the spacing correct it really critical as the CFZ is tiny (Critical Focus Zone, I was trying not to write Critical twice in quick succession, now I have done it three times!)

Get the spacing wrong or the sensor not perpendicular to the focal plain and you will have wonky stars, but the RASA is not alone there. I am still not happy with the corners using my SVX80T, but I have new hardware coming that will change things so settled on "good enough for now"

For something like the RASA I reckon automated focus will be a very good thing to have, though they are probably not as tough to focus as F2 compared to a normal SCT at F6.3 (Reduced) might indicate, and from what I have read they are more focus stable with temperature. The double mirror setup multiplies your pain in the SCT configuration compared to the single mirror RASA both getting it focused and keeping it there. But if you want to be able to leave it imaging all night with sharp subs from end to end automated focus is a great thing, if you like to sleep.