TIME-MARKING HIGH-SPEED FILM IN MULTIPLE-CAMERA INSTALLATIONS

The general time-event correlation problem for high-speed (10,000- frames/second), motion analysis cameras is discussed. The specific optics, sensitometry, and electronics problems involved in placing precise time and event marks on high-speed film, in addition to the design and development of an operational time and event signal generator, are discussed. The generator features a tuning fork time standard, integrated circuit timing logic that can furnish independent time and event signals for up to 15 cameras. A current ramp- film density wedge generator is presented as a novel method for relating time- mark lamp current amplitude to film-mark density. Recently developed, solid- state, light emitting diodes (LED) were investigated for application to the time-mark problem. The LED proved capable of providing time-marking pulses at rates in excess of 200 kHz. A technique for analyzing a waveform to operationally test the neon lamp timing circuit is evaluated. Prepared in cooperation with ARO, Inc., Tullahoma, Tenn.