A HIGH-INTENSITY DIFFUSE LIGHT-SOURCE OF ULTRASHORT DURATION FOR REFLECTED-LIGHT COLOR-PHOTOGRAPHY

For use in reflected-light color photography a diffuse light source ha s been developed which has an annular geometry (347 X 140 mm in diamet er) and coaxially surrounds the optical beam of recording. The light s ource has a luminous peak intensity of 200 Mcd and emits a flash with a duration of 180 ns FWHM. The principle of operation is based on a ch ain of nine V-shaped light-emitting gliding sparks, each consisting of at least 50 interstitial copper electrodes for the generation of micr o gliding discharges. They are all connected in series and driven by a modified nine-stage Marx-surge generator. Substituting each V-shaped gliding spark by two U-shaped Xe-filled flash lamps doubles the light output as well as the flash duration.