Hand Operated Changes

The very earliest printers were probably controlled manually by shutters operated by the operator, who read what was needed from a card. At least one early printer used an edge notch that made a "click" as it passed the gate. When the operator heard the noise and changed the shutter to the next setting.

Some early printers had hand operated changes, for example the Bell & Howell Models D and J printers.

A list of light settings was made out by the grader on a card and the notch on the film edge activated an arm on the printer that moved a pointer to the next light on the card. The light change mechanism itself was a shutter between the film and the lamp which was controlled by a dial and handle operated by the operator. The actual position of the shutter was mechanically stored so that the printer operator could set the handle after a light change ready for the next light.

The light change mechanism of a B&H Model D; the operator had to change the position of the arrow on the big round plate at the right hand side, thus selecting one of the 21 positions.