I just started playing around with this feature on a Panny GH2, which offers up to (I think) 7 or 9 different exposures to be bracketing. Never having experimented with this before, but now really happy with the potential, the following questions occurred to me:
A. Is there some reason (software limitations, mechanical difficulty, etc...) that bracketing must be evenly and sequentially done? IOW, I can set it for -2/-1/0/+1/+2, for example, but why not -3/0/+1/+2.5?
You typically do not want to exceed bracket intervals of more than 1-2 stops in between, to avoid noise differences becoming a problem with the blending or tonecurve reconstruction. The longer exposed frames will have lower shot-noise. There is no absolute obligation to use even spacing between the brackets, other than convenience and for avoiding jumps in noise performance.
B. If I set up for a bracketed shot, and have EV set at something besides 0, for example, will the camera shoot with a bias towards whatever EV is set at? Specifically, if I have EV at, say, -1, with the camera then treat that -1 EV as the 'zero point' if I've set up bracketing for -2/-1/0/+1/+2?
I think that on most cameras, the whole bracketing series will have a -1 EV correction.