I work as a freelance head of the Prop Department for motion picture productions. In past years, everyone used Polaroid cameras to snap instant continuity photos and it worked really well, especially when, for example, we needed to grab several photos at once to document the aftermath of a stunt scene so we could recreate it at another time or place. The white area on the bottom was perfect for using a Sharpie to write down the scene number and any pertinent notes, then we'd punch a hole in one corner and have an instantly accessible ring of Polaroids in script scene order to refer to when nee