Spool Down
Winding an unexposed 400 foot roll down onto four 100 foot daylight spools for use in a camera that will only take 100 feet of film. Spooling down can only be done in complete darkness. 42 turns on a rewind per daylight spool will divide a 400 foot roll pretty evenly. Also, it is vitally important that the film be wound all the way through once and then spooled down, otherwise the edge numbers will be on the wrong side, and not printed onto the workprint.