GrazingOli - with your new purchase you are right where I am - an F6 refractor (mine is 105/650), and here is my dilemma. Using round numbers for seeing of 3: star size= 3*600/200= approx 9 microm, and we want pixel size to be 1/3 star size = 3 microm. The ASI294 camera doesn't meet this criteria (4.6microm). The ASI 183 does at 2.4 and the 290 does at 2.9. If seeing improves the pixel size drops, so I am thinking for 600mm fl we need as small a pixel size as possible (offered).
We are not exactly in the same situation
I am a bloody beginner, not quite sure about your math AND I also got a CPC800. The ASI294 was acutally recommended as a follow up for my ASI120 as causing not so much oversampling with the SCT. If I do not care about seeing conditions, using the following formula
Image Scale = Pixel Size / Focal Length * 206 (Ideal Range between 1 to 2) it looks not too bad for the BW100 scope
BW100 /w ASI120 fl600 -> 1.29 quite good
C8 f6.3 /w ASI120 fl1280 -> 0.60 oversampling and very small field
BW100 /w ASI294 fl600 -> 1.59 really good
C8 f6.3 /w ASI294 fl1280 0.75 -> better than ASI120 and reasonable field
Your math does not really make so much sense to me, because under seeing of 3 you take the whole thing times 3 and then you divide it by 3 at the end, which means that the result is the same with or without seeing. However I do not know where your math comes from so I cannot really validate it.
What I saw, reading through the boards, is, that a lot of people seem to do quite well with oversampling, especially when using SCT or even MAK scopes with CMOS cameras. However small pixels with high resolution also means a lot of data to be handled by the hardware. So I would not want to go too high in order to use my Core i5 notebook for a while. And also it seems to be a bit of a trial and error affaire which camera works well with which scope under certain seeing conditions. Last but not least: there is not one single setup for all celestrial objects, as you said already. Planets and Moon will require a different setup than DSO.
My targets will be DSO, mainly galaxies and planetary nebulae. See what I can achieve with the ASI120, mainly with the f6 scope.
Edited by GazingOli, 03 May 2020 - 12:40 AM.