A New Flash Illumination Unit for Ballistic Photography

摘要

A description is given of a flash illumination source of very high peak intensity which has been recently developed in this laboratory for use in conjunction with Kerr cell and image converter type cameras. The electrical circuit of the unit permits three standard commercial flash tubes of the Egerton type to be operated simultaneously using only one energy storage capacitor, one trigger circuit, and a single high voltage power supply. A comparison is made between the circuit of the present unit and those of previous flash illumination sources particularly with regard to (a) peak flash intensity, (b) effective flash duration, (c) efficiency of conversion of the total stored electrical energy into useful light output, and (d) reliability of triggering. Possible modifications of the present unit to enable it to be used as a flash source in the conventional ``open shutter‐single flash'' photographic technique are discussed.