A multiple-spark light source and camera utilizing the Cranz-Schardin optical method for schlieren and silhouette photography is described. Each light source is a spark in air, with an effective duration of 10-7 second and a peak of light of 24,000 candle power. The interval between successive sparks is independently adjustable from 10-5 to 10-7 second, permitting a variable picture rate to be used in a single sequence of photographs. The equipment contains ten spark light sources and camera lenses, permitting a ten picture sequence of high speed phenomena. Schlieren and silhouette photographs demonstrating the performance of the equipment are presented.
David G. Kocher,
"A Multiple-Spark Light Source and Camera for Schlieren and Silhouette Photography," Optical Engineering 1(6), 106207 (1 September 1963). https://doi.org/10.1117/12.7971238