Shutter speed is the amount of time the shutter remains open to allow light to reach a digital camera sensor. Shutter speed is measured in seconds, or fractions of seconds.
Using very fast shutter speeds “freeze” fast-moving subjects, such as birds in flight. Slow shutter speeds are used to intentionally capture the movement of a subject.
How an image is exposed is determined by the combination of the lens aperture and shutter speed. A fast shutter speed uses a larger aperture (small F-stop number) to avoid an under-exposed image. A slow shutter speed requires a small aperture (large F-stop number) to avoid over-exposure.
Typical shutter speeds are: 1/2000 second, 1/2000 sec, 1/500 sec, 1/250 sec, 1/125 sec, 1/60 sec, 1/30 sec, 1/15 sec, 1/8 sec, 1/4 sec, 1/2 sec and 1 second. On some digital cameras you can manually set shutter speed a lot slower than a second for very long exposures.
For most, hand holding a digital camera at shutter speeds below 1/60th of a second often require use of a camera support to prevent camera shake.
Shutter Priority Mode
Shutter Priority mode is a semi-automatic exposure mode. You select the shutter speed and the camera automatically sets the aperture for a proper exposure.
For digital cameras without Shutter Priority use Sports, Kids and Pets or Fast Shutter mode.