Exposure Value (EV) is a numerical system that represents the combination of shutter speed and aperture settings used to achieve a correct exposure on a photographic scene. On older cameras and light meters, photographers could set a single EV number, which corresponded to a specific pair of shutter speed and f-stop combinations, simplifying exposure calculations. EV provides a standardized way to compare brightness and exposure across different lighting conditions and camera settings.
Understanding EV is important for photographers who work with manual cameras, film, or older light meters, as it helps determine the correct exposure without constantly calculating individual shutter and aperture adjustments. It also provides a foundation for modern exposure techniques, including exposure compensation, bracketing, and creative control over depth of field and motion blur. By mastering EV, photographers can achieve consistent, well-exposed images in a variety of lighting situations.