Photographed at sunrise in July, 2009, this young male lion, in beautiful condition, walked across the floodplain in front of us, patrolling his territory, stopping occasionally to scent mark as he did so. In my eagerness to photograph him, I accidentally engaged exposure compensation on the camera, a mistake I didn't recognize until after I'd taken a series of 20 or 30 shots and he'd walked out of view. I pulled out several strands of my own hair in frustration when I reviewed the images and saw that the entire series was heavily underexposed, probably by about 3 stops.
On getting home and downloading my digital files, I opened the image up in Lightroom 2.5 and adjusted the RAW file adding 2 full stops of exposure. Whilst not a process I'd knowingly repeat, the image still ended up being worthwhile. We learn from our mistakes! Fortunately, the current state of digital technology gives a great deal of flexibility and in this case was forgiving enough to still end up with the final result shown.
Canon 5D, focal length 500mm at F4.0, shutter speed 1/8000 second at ISO 1600. (Unintended exposure compensation resulted in significant under exposure).