Answer
May 21, 2025 - 12:00 PM
The emission of flash light is the illuminance changing with time. It cannot be expressed with the unit of Lux or Foot-candle.The exposure value for flash light is expressed with the combination of shutter speed and focus value. Using the flash light mode on exposure meters, you can measure cumulative flash value in shutter speed. If shutter speed is set longer than the flashing time, your exposure meter measures the flash-light integration via flashing time.
