Abstract: An apparatus for triggering a flash in a gas discharge lamp includes a power supply; a current limiter operatively connected between the power supply and the lamp to limit the current flowing through the lamp to a first preselected level; and a shunt path operatively connected between the power supply and the lamp to selectively increase the current flow through the lamp to a second level higher than the first level to produce a flash of increased brightness. Independently or in conjunction with the flash circuit, magnetic fields can be applied to the gas discharge lamp to increase electron path length in the plasma, increasing the optical output of the lamp.