Flash duration is the measurement of time that a photographic flash emits light, typically calculated from the moment it reaches 50% of its peak intensity until it diminishes back to the same level. This measurement helps photographers understand how long the light effectively illuminates a scene during exposure.
Flash duration is an important factor in capturing fast-moving subjects or freezing motion, as shorter flash durations can stop action more effectively. High-speed photography and studio lighting setups often rely on precise flash duration to ensure sharp images and consistent lighting, making it a critical specification for both professional and enthusiast photographers.