Exposure is a term used in photography to describe the amount of light that reaches the cameras sensor or film, creating visual data over a period of time. It is determined by shutter speed, lens F-number, and the illuminance at the photosensitive material). Exposure time is controlled in a camera by shutter speed, and the illuminance depends on the lens aperture and the scene luminance). A long exposure refers to a single, long shutter cycle to gather enough dim light, whereas a multiple exposure involves a series of shutter cycles, effectively layering a series of photographs in one image). The accumulated photometric exposure is the same so long as the total exposure time is the same). Correct exposure may be defined as an exposure that achieves the effect the photographer intended).
Apart from photography, exposure can also refer to the condition of being presented to view or made known, the condition of being unprotected especially from severe weather, the condition of being subject to some effect or influence, the manner of being exposed, the position (as of a house) with respect to weather influences or compass points, and a piece or section of sensitized material (such as film) on which an exposure is or can be made.
