Eliminating potential for human error and tampering, QuadCam identifies objects and people moving in and around machinery, distinguishing between one, 2, or more persons with real-time tracking. It allows users to define warning and shutdown zones, and provides visual and audible warnings when warning zone is breached. Single imager protects up to 8 x 10 ft zone when it is mounted at 11 ft. Up to 10 imagers can be managed by single QuadCam controller, monitoring up to 800 square ft.