for my 5x7 pinhole I use a change bag. I sit on the ground and put the camera and two paper envelopes in the bag and get the exposed sheet into the exposed envelope and a new sheet into the camera... takes about 3-4 minutes! I stuck some tape with a flap poking out onto one envelope to indicate the exposed one. For my 8x10 pinhole, I use it one shot... have to take it back to the darkroom to empty and reload.