ARRI Ultra Distance Measure (UDM)

The Ultrasonic Distance Measure UDM-1 measures the distance between film/sensor plane and objects by sending ultrasonic pulses and measuring the time they take to bounce back. It is compatible with any camera system. The UDM-1 comes with a sensor module and a display unit that indicates the measured values on a transflective screen. When used with ALEXA Plus or Studio cameras or the Universal Motor Controller, the measured distance will be instantly displayed on the WCU-4 hand unit. The UDM-1 also enables ALEXA Plus or Studio cameras and the Universal Motor Controller UMC-4 to do focus tracking – setting the focus motor to continuously follow measured distance of a subject in the frame.