P7100 Exposure compensation
Could you have possibly had your "Mode" set to "Manual"? Exposure dial twiddling would then not override the exposure value settings you had set via the dials.
Upload some exif, we can check what happened. For something like that, shoot RAW only, as the JPGs are only taking up resource.
If you shoot for HDR in manual, you need to adjust the shutter speed (or aperture) up or down via the camera control dials, not the exposure compensation dial.
Aside from this, I cannot think of anything else at the moment.
Cheers, please advise the outcome, am scratching my noggin over this one!
LIFE is a 'long exposure'... and full of 'noise'. Wouldn't want it any other way!