feedback control

Definition: Electronic or other system designed to control the output of a device by transferring or feeding back a portion of its output signal. * The returned signal is used to measure the output or response to the output, thus to control the relationship between the input and output signals. * Used e.g. (a) in colour enlargers to maintain an accurate output (b) in flash-guns in which the light reflected from the flash is measured and used to control the exposure.

Previous Term: feedback  Next Term: F-line

Type a photography term below to find its definition: