The Fader Mechanism

Most modern light valve printers have a fader fitted. A fader reduces the overall light reaching the film to zero at a pre-defined rate, or increases it from zero to set value. The point at which a fade occurs is determined by the printer light punched tape. A special position on the tape has holes to pass the information to the printing machine to programme the start of a fade; it's direction [fade up, or, fade down] and the length of the fade.

The Bell and Howell Model C has six different possible lengths of fade: 16, 24, 32, 48, 64 and 96 frames.