Diffuse illumination electronic flash - has combination of direct and variable flashes simultaneously fired and mutually compensated

摘要

The electronic flash gun attachment is for a camera in which two discharge tubes are used; one (17) on the main gun housing and one (19) on a variable geometry head (12). The variable flash is used for a bounce effect, with any loss in illumination compensated for by the direct view flash. The gun is used for indoor exposures and the combination of the two flashes provides a more diffuse and shadowless illumination. The two discharge tubes are fired using a capacitative discharge with a quench signal when the integral photocell (15) has monitored sufficient subject illumination. The electronic circuit includes a quench control stage with a capacitor in parallel with a resistor to cut off the illumination power after a specified interval.