Here's a video of how the Canon EOS 600 slr camera swallows your film. It cannot be simpler.
When the 36th frame is shot, the camera will automatically spool the whole thing back into the cartridge.
Unfortunately this camera is automatic so you cannot win yourself an extra exposure or two by not winding the film too much at the beginning. It is all set in stone... or technology.
I wonder how it recognizes 24exp cartridges. Either it reads the barcode thingie, or it automatically rewinds at the slightest sense of resistance to winding.
