Photographic strobe apparatus

Claim 1

A photographic flash circuit having an electronic strobe tube operable at high voltage to produce a relatively large amount of illumination of high intensity, said circuit having a storage capacitor of relatively small capacitance, means for charging said capacitor to a relatively high voltage, means for coupling said storage capacitor to said strobe tube, and means for triggering said strobe tube into conductance to thereby produce a short, high intensity pulse of illumination responsive to discharge of said storage capacitor through said strobe tube, the improvement comprising: means for automatically producing a relatively small amount of additional illumination of relatively constant low intensity from said strobe tube following said high intensity pulse, and means operable for terminating said low intensity illumination to thereby provide precise control over the total illumination produced, said producing means including an auxiliary capacitor of comparatively large capacitance, means for coupling said auxiliary capacitor to said strobe tube so as to permit current flow thereto while blocking current from said storage capacitor to said auxiliary capacitor whereby, following charging of said capacitors and upon triggering of said strobe tube, a burst of high intensity illumination of relatively short duration is automatically followed by additional illumination at an approximately constant level of comparatively low intensity for a comparatively long duration whose termination can be controlled to determine the total illumination.