I have done a careful experiment where I took the same set of exposures of the same object with and without in camera noise reduction on. Also took darks and flats and bias frames. Processed both lots and I think the ICNR won hands down. It is almost impossible to get dark frames that match the exposure unless the camera temperature is exactly the same.
Look here
http://www.iceinspace.com.au/forum/s...ead.php?t=9500
Yes ISO is irrelevant if you use ImagesPlus and careful post processing and the lower the ISO setting the greater the dynamic range. I am next going to try exposing at an ISO of 50.
Also see here
http://www.clarkvision.com/imagedeta...gnal.to.noise/
ISO is taken into account when the camera produces the JPG image or you use any 'normal' software to get Tiffs etc from Raw frames.
Bert