In addition to controlling the exposure, the shutter speed can affect the appearance of the subject – especially if the subject is moving.
Sukhoi Su-35, © Richard Deakin 2013, Canon EOS-1D X
A very fast shutter speed (1/1000 second, for example) can ‘freeze’ movement, making your subject appear motionless in its environment. A slow shutter speed, perhaps several seconds, will make a moving subject appear blurred. This can be especially effective if you shoot with the camera on a tripod, as anything not moving will still appear sharp while the moving elements in the scene are blurred to represent their movement.
With your EOS, you can set the shutter speed using Shutter-priority AE (Tv) mode. You select the shutter speed and leave the camera to choose the aperture for correct exposure.
It rains, © Regine Heuser 2013, Canon EOS-1D Mark IV
A fast shutter speed has been used to ‘freeze’ the movement of the dog as it bounds through the water. Some of the water droplets have also been captured in mid-air. To maintain a suitable exposure, a wide aperture is often needed when using a fast shutter speed. In this photograph the wide aperture has given a narrow Depth-of-Field, making the dog stand out from the background.
Bern Station, © Crivelli Daniele 2012, Canon EOS 5D
Here is an interesting use of a slow shutter speed. The camera is on a tripod and the woman with blonde hair is standing still. This means that she appears quite sharp in the photograph. However, the two passers-by and the train are moving and appear blurred in the image.