A
flash is a device used in
photography producing a flash of
artificial light (typically 1/1000 to 1/200 of a second) at a
color temperature of about 5500 K to help illuminate a scene. A major purpose of a flash is to illuminate a dark scene. Other uses are capturing quickly moving objects or changing the quality of light.
Flash refers either to the flash of light itself or to the
electronic flash unit discharging the light. Most current flash units are electronic, having evolved from single-use flashbulbs and flammable powders. Modern
cameras often activate flash units automatically.