Interesting reading, it appears there's not much advantage in stacking more than 15. I remember something similar when I used to to use a Gstar to take deep sky pictures , there was little diifference between a stack of 1000 x2.5sec exposures (integrations) and a stack of 200x2.5 sec exposures. However , if this is true for long exposures why do so many expert imagers stack 100's of hours of exposures . I find it difficult to get several hours of exposure time !
Philip
