What are you considering "saturated"? For "most" of the stars to saturate, you would have to be rather wildly overexposed. Even with heavy LP, unless you are imaging at an extremely wide field with a very fast scope or lens, I would expect "some" but definitely not "most" stars to clip at 120 seconds for Gain 0. For more normal scopes, though, with the tiny pixels, and a 15ke- FWC, it should be pretty hard to saturate stars with this camera unless your image scale was 2-3"/px or more and a fairly fast f-ratio.
Are you looking at a stretched image to determine which stars are saturating? Or are you looking at the unstretched linear image? And, when you say "saturated"...are you actually measuring the stars to see if they have indeed saturated (reached maximum signal)...or are you just assuming that every star that is visible in the linear signal field is "saturated"? If the latter...then my guess is only some of the stars you can see in the unstretched image are actually saturated. You can start to see stars in an unstretched sub LONG before they even get close to saturating. Saturation is only when they actually clip at maximum signal.
Pretty close, but, as a practical matter, my experience is somewhat different. At high speed, the field doesn't have to be _that_ wide, and the image scale numbers you cite could be somewhat misleading.
With my F2 RASA, I can saturate "too many" stars for my taste with a 183color (which is harder to saturate) at 20", gain 50. (Some guy I know here suggested lower gains could be trouble, and his advice is generally excellent. <smile>) 1.2 image scale.
This is pretty marginal, and it's 150X15".
And yes, "too many" stars are saturated in individual subs. Not that I know how to fix saturated stars in final images without complicated HDR techniques. <smile>
Edited by bobzeq25, 20 September 2019 - 10:37 AM.