Flash

Flash refers in photography to a device that generates a flash of light instantly. There are different reasons for which a flash is used, such as creation of a different light intensity than the prevailing ambient light condition, for brighter light to capture fast moving objects, as well as for providing light in cases where the light not adequate for appropriate exposure to the photograph.

In the lower spectrum of commercial photography, the flash units are in-built parts of the cameras, while in the higher-end cameras, the flash comes as a separate unit that needs to be mounted through a standardised accessory mount bracket. For professional studio photography, large standalone units or studio strobes are used as flashes.

Initially, these camera accessories were comprised of a certain quantity of magnesium powder, which was actually ignited by hand. This system was later replaced by flash bulbs containing magnesium filaments that were electrically ignited by a contact in the camera shutter. Kodak came up with the Flashcube in the 1960s, which had four electrically fired flashbulbs that allowed taking four images in a row. Most of the cameras these days feature an electronic flash. Having a tube filled with xenon gas, the flash discharges high voltage electricity for producing an electrical arc that generates a short flash of light.