So there seems to be two styles of Rittreck View film backs available in at least the 5x7 and Whole Plate sizes. One looks like a modern spring-type back where you slide the film holder in under the ground glass and spring pressure keeps the film holder pressed against the film back. The other style looks like this:





It looks like the ground glass latches in place and then you swing it out of the way to put a film holder in place. However, I can't figure out how the film holder is supposed to stay in place for the exposure.

Anyone know?