I shoot som Fuji instant packfilm in a Polaroid 405 on my 4×5 cameras. The picture size on Fuji film are are smaller then the 4×5 so it has always been kind of a calculated guesswork as I have no mask for the format. So I decided to make one out of matboard cutting the same size as a regular film holder or the 405 and measuring where the aperture should be. Now I can insert it and frame my picture, take it out and adjust focus, put in the 405 and shoot. I will do one that I can put over the ground glass, I think that would make more sense to just hold it up on the glass even if this would work on any 4×5 camera. But life is about progress and this is a start:)
