Final answer:
The burst of current for a camera's electronic flash is produced by the rapid discharge of a capacitor. Capacitors store and release energy quickly to create intense flashes of light that can capture images in low-light conditions. The charge process is slower than the discharge due to limitations in the charging circuit and power source.
Step-by-step explanation:
When an electronic flash on a camera flashes, the burst of current used to create the flash of light is produced by the rapid discharge of a capacitor. A capacitor is able to discharge quickly, releasing a large amount of energy in a short time period, which creates the bright light necessary for photography in low-light conditions. The reason the flash can illuminate a scene almost instantaneously is that the discharge through the flash tube, which contains a low-resistance ionized gas, happens very rapidly, allowing flash photographs to capture even the briefest instances of rapid motion in less than a microsecond and with intense brightness.
The process of charging the capacitor takes longer because it involves transferring charge to the capacitor at a rate limited by the resistance and inductance in the charging circuit, as well as the available current from the battery or power source. The capacitor stores a high voltage which, when discharged, powers the flash through a process involving an oscillator system and sometimes a transformer, depending on the design of the camera flash.