- Date: 1605]
- 1 : the fact or condition of being exposed: as a : the condition of being presented to view or made known <a politician seeks a lot of exposure>
- b : the condition of being unprotected especially from severe weather <died of exposure>
- c : the condition of being subject to some effect or influence <risk exposure to the flu>
- d : the condition of being at risk of financial loss <minimizes your exposure to market fluctuations>; also : an amount at risk
- 2 : the act or an instance of exposing: as a : disclosure of something secret <tried to prevent exposure of their past>
- b : the treating of sensitized material (as film) to controlled amounts of radiant energy; also : the amount of such energy or length of such treatment <a 3-second exposure>
- 3 a : the manner of being exposed
- b : the position (as of a house) with respect to weather influences or compass points <a room with a southern exposure>
- 4 : a piece or section of sensitized material (as film) on which an exposure is or can be made <36 exposures per roll>
In photography, exposure is the total amount of light allowed to fall on the photographic medium (photographic film or image sensor) during the process of taking a photograph. Exposure is measured in lux seconds, and can be computed from exposure value (EV) and scene luminance over a specified area.
In photographic jargon, an exposure generally refers to a single shutter cycle. For example: a long exposure refers to a single, protracted shutter cycle to capture enough low-intensity light, whereas a multiple exposure involves a series of relatively brief shutter cycles; effectively layering a series of photographs in one image. For the same film speed, the accumulated photometric exposure (H) should be similar in both cases.