Shutter speed
Glossary Terms
'Shutter Speed is the amount of time the shutter is open. Slow shutter speeds can give motion blur, or increased camera shake; higher speeds can freeze fast action and reduce shake.
Slow shutter speeds may allow small lens apertures, giving greater depth-of-field, whereas high speeds can be used with large apertures - for separating a subject from an out-of-focus background.
Fast shutter speed in low-light situation may be possible with high-ISO film or high-ISO setting of a digicam but may give results with less image resolustion or more noise.
For more on shutter speeds, see exposure.