>>4148541because that's not what he said, bracketing is just auto mode of taking 0EV exposure, -1 under and +1 over, in 7 steps is basically doing that with 7 pics each a third stop apart,
over or under exposure is relative to the scene and camera, perfect as measured exposure might be wrong due to backlighting or spot lighting and anything really, there's no such thing as perfect exposure, so brakceting allows you to get a rnage and pick the best, plus or minus 1 stop though isn't really enough to vary much