Exposure is the amount of light that reaches the camera sensor or film during capture, determining how bright or dark the resulting image appears. Proper exposure balances the brightness of the image so that detail is visible in both highlights and shadows without significant clipping or loss of information at either extreme.

Exposure is controlled through three primary variables known as the exposure triangle: aperture, which determines how much light enters through the lens; shutter speed, which controls how long the sensor is exposed to light; and ISO or sensor sensitivity, which amplifies the signal captured by the sensor. Each of these controls affects not only exposure but also other visual characteristics like depth of field, motion blur, and image noise. In professional cinematography and photography, achieving correct exposure while maintaining desired creative characteristics across these variables is a fundamental technical skill.

In AI image and video generation, exposure characteristics are typically inherited from the training data and can be influenced through prompt language describing lighting conditions, brightness levels, or specific exposure aesthetics. Terms like underexposed, overexposed, high-key, or low-key help models understand the intended brightness and contrast characteristics of the output, allowing creators to direct the tonal range of generated content.