Originally posted by biz-engineer There's a line amplifier in front of the ADC, that's why if you use ISO6400 you get let noise than if you use ISO100 underexposed by 7 stops, and that's where it's better to have a 14 bits ADC rather than a 12 bits ADC. From 12 bits to 14 bits won"t help to get a better DR, but it will allow a cleaner higher ISO settings.
I'm sure that DPR did a test where they came to the conclusion that with a particular camera (think it was a Nikon D810), more or less the same shadow information was captured whether shooting at high ISO, or underexposing at low ISO and lifting everything in post. From what I remember, apart from minor differences in colour balance and tonality, largely down to how they had processed it, there was very little difference in the output from an ISO100 shot, underexposed by say 6 stops, and boosted in post, and an ISO6400 shot as is. It may not have been a D810, but it was definitely a Nikon with the Sony sensor. They compared it to a Canon model - think it was the 5DIII - which was a completely different story and there was huge benefit to using the high ISO.
This seems at odds to what you are saying, at least for some cameras/sensors.
I would provide a link but I can't find it now. Anyone remember this? It wasn't that long ago.