Abstract: A standby control attachment for an x-ray film processor uses infrared light reflection to detect the presence of a film in the infeed tray of the processor. A trigger circuit produces a control signal to activate a timer when film is detected. The timer operates processor control relays to switch processor components from a normal standby mode to a processing mode only for a preset timing interval to minimize water and energy consumption and processor wear. Multiple infrared detectors, each with its own trigger circuit, are arranged above the tray and across the film path so that detection of film by one or more of the detectors activates the timer. Control signals from the separate trigger circuits are also applied to auxiliary control devices, one of which activates a darkroom interlock system to lock darkroom access doors and break its white light circuit when film is in the tray.