Is this possible? If so, I would like to hear from anyone actually doing it. Is the 5" dimension in 5x7 film the same as the 5" dimension in 4x5? It would be nice to occasionally use some 4x5 emulsions not available in 5x7 without the expense and added carry-weight of a reducer back. I would assume that some temporary guide-strips would need to be rubber cemented into the holder to keep the film from sliding around. What about loading - could the film just be curved and popped under the guide rails of the holder? How could the film be removed?