If you use a digital camera with a 16:9 format sensor, you may have "hidden" pixels in your photograph when shooting in a 4:3 or 3:2 aspect ratio. The camera actually records the full 16:9 frame, even if you choose not to see it. Now there is a free (but unsupported) Photoshop plugin that allows you to recover those edges.
DNG Recover Edges is a utility offered at Luninous Landscape that allows you to do this.
