Is it worth it to take some dark frames before and after the "light" sequence, to have a better "map" of hot pixels and noise, or only after the light sequence is the right way to go?
Yet, I do noticed a difference in time on long exposures on my D7000. Usually when I need long exposures on intervals, I use the Promote Control: if I set 30" I get 32". If I set more, it's proportional. I thought it was the Promote Control... until I read this thread. I still have to check with the camera alone.