[en] Optical sources of several megawatts-cm^-2 over large surface areas are available from electrical discharges initiated by exploding films and wires immersed in a gas. Discharging high-current capacitor banks into the metal conductors causes them to melt, vaporize, and then eventually ionize to a high-conductivity plasma of less than a milliohm/cm-length resistance. As such, over 1000 MW of ohmic heating goes into the discharge, elevating its blackbody temperature up to 35,000 K. In this work, film thicknesses from 0.1 to 10 μm and wire diameters from 0.051 to 0.25 mm with lengths ranging from 8 to 90 cm were exploded and the brightness temperatures measured in the spectral regions about 200, 280, and 520 nm. The optical emission generally increased with the time rate of change of the current, the current per unit diameter for the films, and the gas pressure in the cell, but showed little dependence on the mass or kind of metal exploded. The discharge radius expanded at velocities of approximately 1.5 km-s^-1