When we take a picture, the camera’s shutter opens to allow light to reach the recording medium, where an an image is created. By controlling how long the shutter stays open, we can control what the resulting image looks like.

A slow shutter speed keeps the shutter open for longer. This not only allows more light to be recorded, it also means any moving objects will appear blurred. Slow shutter speeds are commonly used for photographing in low light conditions, or to capture motion blur. To avoid any unwanted extra blurring caused by camera movement, be sure to use a tripod when shooting with slow shutter speeds.

Slow shutter speeds can be used for creative techniques such as panning, or combined with flash to capture both frozen and blurred movement. 

A good rule of thumb is to avoid using a shutter speed value below that of your focal length. For example, if you’re shooting with a 50mm lens, don’t go lower then 1/50. If you’re shooting with a 200mm lens, don’t go lower than 1/200. If you do, it might be necessary to use a tripod.

Faster shutter speeds keep the shutter open for a shorter period of time, allowing less light to reach the recording medium. Faster shutter speeds will also freeze movement and are often used to photograph fast-moving subjects like athletes or wildlife.

If you’re shooting in Auto, the shutter speed (along with the aperture) is determined automatically by your camera. 

If you want to get out of Auto mode and experiment with shutter speed without worrying about aperture, you can use Shutter Priority mode (shown as TV or S). Great for beginners, this mode is also used by professionals shooting in conditions where the light changes quickly and often.

In Manual mode, you set both shutter speed and aperture yourself. On DSLR cameras, you can see the shutter speed on the top LCD panel, on the back screen and through the viewfinder.

How you set the shutter speed varies from camera to camera. Some cameras even allow you to set which control wheel you use.