I'm not sure if it's addressing what you're talking about, but I try to set exposure to capture the information in RAW, and then post process using the tone curves (in addtion to exposure compensation) to set the subjective brightness. I've seen lots of things where somebody tried to keep the dark feel, and as a result wastedtons of their dynamic range, and as such, had no detail at all in the shadows.


As for the original issue, I don't deal with low light exposure issues any differently than high light. To me, it would seem that the relationshipos between Aperture, Exposure time, and ISO remain the same.