The shutter speed of a camera depends on two variables: the size of the lens and the actual timing of the shutter, opening and closing. These two factors work as a team to control the amount of light that enters the camera. This is measured in fractions on a shutter speed dial which illustrate how long the shutter opens and closes in a set period of time. The term speed refers to how long the lens remains open. For example, a setting of 1/60 on a shutter speed dial means that the shutter opens and closes within one sixtieth of a second. Various shutter speeds can be used to manipulate the final result of the picture. Usually, a faster shutter speed is used to freeze the scene, for motion shots, while a slower speed is used to create more of an unfocused, abstract result.