The NPC ProBack was a pretty nifty idea, if not a waste of film
Once in awhile, you come across a photography contraption whose purpose or use eludes you. Some of the ones that occasionally still pop up on eBay and photography forums is the NPC Polaroid ProBack, a camera back that was designed to take Polaroid peel-apart instant films for checking exposure, lighting, and composition on the spot. Back in the days, Polaroid films had a different purpose in photography than what most of us today use (and love) them for. They were very helpful for photographers who needed precise exposures for demanding projects. For those who wanted or needed to do this without an actual Polaroid camera (or wanted to get a preview of their camera setup), there was the bulky and unwieldy Speed Magny for those used Nikon F cameras. The cool factor of this was that the back essentially turned the 35 mm Nikon F camera into an instant or large format camera.