In photography and
digital photography
the shutter speed is the unit of measurement which determines how long
shutter remains open as the picture is taken. The
slower the shutter speed, the longer the exposure time. The shutter speed and
aperture together control the total amount of light
reaching the sensor. Shutter speeds are expressed in seconds or fractions of a
second. For example 2, 1, 1/2, 1/4, 1/8, 1/15, 1/30, 1/60, 1/125, 1/250, 1/500,
1/1000, 1/2000, 1/4000, 1/8000. Each speed increment halves the amount of light.
See also aperture.