A lightweight, small, high-voltage power supply for a xenon flash lamp or strobe permits rapid and reliable strobing for retinal imaging. In one embodiment the power supply can develop 500 volts at 720 watt seconds to permit firing the xenon strobe at full power one pulse per second. The power supply, rather than using heavy, bulky transformers, uses a hybrid high-voltage multiplier that involves an AC coupling circuit and a half-wave rectifier, the outputs of which are coupled in series to a capacitor bank to achieve a 500-volt charging source for the capacitor bank. This permits the capacitor bank to be charged with a continuous high voltage so that it can deliver a controlled, reliable high voltage to the xenon strobe.