Eksponeringsværdi

Eksponeringsværdi, often abbreviated as EV, is a concept in photography that represents a combination of aperture and shutter speed that results in the same exposure. It quantifies the amount of light that reaches the camera's sensor. Each increment of a full EV step represents a doubling or halving of the light. For example, an EV of 10 allows in the same amount of light as an EV of 11, but with either a wider aperture or a slower shutter speed, and the same amount of light as an EV of 9, but with either a narrower aperture or a faster shutter speed.

The relationship between aperture (f-stop) and shutter speed to EV can be illustrated with a simple formula. For a given EV, there are multiple combinations of f-stop and shutter speed that will produce the same exposure. This allows photographers flexibility in choosing settings based on creative intent, such as controlling depth of field (with aperture) or capturing motion (with shutter speed), while maintaining the desired overall brightness of the image.

Modern digital cameras often display EV values in their manual modes, assisting photographers in setting their desired exposure. Understanding EV helps in making informed decisions about camera settings, especially when dealing with varying light conditions or when aiming for specific photographic effects. It provides a unified measure of exposure, simplifying the complex interplay between aperture and shutter speed.