Length of time when the film or digital sensor inside a camera is exposed to light
In photography, shutter speed or exposure time is the length of time that the film or digital sensor inside the camera is exposed to light (that is, when the camera's shutter is open) when taking a photograph.[1]
The amount of light that reaches the film or image sensor is proportional to the exposure time. 1⁄500 of a second will let half as much light in as 1⁄250.
^
Sidney F. Ray (2000). "Camera Features". In Ralph Eric Jacobson; et al. (eds.). Manual of Photography: A Textbook of Photographic and Digital Imaging (Ninth ed.). Focal Press. pp. 131–132. ISBN0-240-51574-9.