shots in rapid succession. In the mid-20th century, some sheet film sizes, including medium format, were made in "film packs" of 12 to 16 exposures, which are thin sheets of film and folded into a rectangular pack which was placed in a pack holder camera back. Some large format cameras have rotating or sliding reduction backs, which mask off part of the film sheet, allowing several smaller photos to be placed on a single sheet of film. See also View camera Film format Speed Graphic References External links Paul Butzi's Readyload/Quickload review Readyload/Quickload information from largeformatphotography.info Sheet Film and Roll Film Holders for large format cameras More notch codes on this reference page Film formats