a photographic lighting system , particularly for use in photographic studios , including a constant light for illuminating the subject to be photographed while the subject is being placed in proper position and while the photographer is focusing the camera , plus an electronic flash device for illuminating the subject while the actual photograph is being taken . the constant or continuous light is adjustable to vary the degree of illumination produced thereby , and the duration of the electronic flash is automatically adjusted to vary the duration of the flash , in response to the adjustment of the brilliance of the continuous light . the electronic flash tube is powered by a storage capacitor , and charge control means determines the voltage to which the storage capacitor is charged in preparation for an ensuing flash . blocking means prevents the initiation of a flash unless the storage capacitor is charged to the proper voltage .