Transferring the image from negative to positive.
The Film Printing Machine
During printing, the image on a negative is copied by passing light through it to expose the raw print stock. In continuous contact printers, negative and raw stock are placed together, emulsion-to-emulsion, and moved steadily past a light beam slit. The exact colour balance of the printing light can be controlled during the print run to give colour corrections for different scenes in the film. Fast-running continuous printers are used for the rapid turnaround of work prints, as well as for fully graded answer prints and for high volume bulk release printing.
The image from continuous contact printers is quite steady enough for normally ...