The Wollensak (Weston) Fastax Exposure Meter Model 757 / 9916: The Fastax, made by Wollensak, was a high-speed 16mm analytical cine camera. It could shoot up to 10,000 frames per second. Weston created an exposure meter for Wollensak especially to support this camera - hence the name Wollensak on the meter face. It was an adaptation of their earlier model 756 - a standard meter of this particular design. The Fastax meter differs in that the paddle housing the Selenium cell holds only one cell and not two as in the 756. It also has a 2 stage rotating baffle giving it 3 ranges.
The paddle-mounted cell was separated from the main meter by a cable. This allowed it to be placed remotely across an awkward subject area being covered by the camera. Very bright lighting was required for the camera as the effective shutter speed was so fast. So the paddle unit was designed to be much less sensitive than that of the 756 model and the meter reads in foot candles x1000 accordingly.
The cell and meter are very accurately set up - to the extent that the serial number is stamped onto both units and they are not interchangeable. Since the meter only measures foot-candles, a separate printed calculator is provided to translate the readings into exposure.