How does the exposure slider work in Adobe Camera Raw/Lightroom?
Naively I would expect the exposure slider to be a simple linear scaling (in the input color space, not in the working color space), but it's obviously not that. It's applying some sort of compression because you can increase it a lot without blowing up your highlights. Is this compression curve documented somewhere?
Related to that, do the numbers in the exposure slider have any absolute meaning? E.g. I have seen people claim -1.0 is one stop less exposure, but I don't think that's right. When I use graduated neutral density filters I use 0.6 and 0.9 grads (2 and 3 stops), but when I achieve the same effect in Adobe Camera Raw I rarely need to do more than -1.