When I take an exposure bracket (0, -1, +1) I've noticed on more than one occasion that certain parts of the -1 photo (1-stop darker) has lost sharpness of focus. Often the -1 photo is the best exposed because it doesn't have blown highlights so I want to keep it, but the loss of sharpness is a problem. The problem is particularly noticeable in the darker areas and becomes obvious when, say, a face is in shadow because of a hat. The face in the "0" exposure is sharp, but is obviously not sharp in the "-1" photo.
What causes this? Is it because:
1. Darker images are inherently less sharp?
2. Camera shake from by the first snap propagating into the second snap?
3. Me not holding the camera steady?
4. The optical stabiliser stabilises the first snap, but incorrectly stabilises the following snap?
What causes this? Is it because:
1. Darker images are inherently less sharp?
2. Camera shake from by the first snap propagating into the second snap?
3. Me not holding the camera steady?
4. The optical stabiliser stabilises the first snap, but incorrectly stabilises the following snap?