shutter speed

The camera's shutter speed, the lens's brightness and the scene's luminance together determine the amount of light that reaches the film or sensor.is a quantity that accounts for the shutter speed and the f-number. Multiple combinations of shutter speed and f-number can give the same exposure value. According to expose value formula, doubling the exposure time doubles the amount of light. In addition to its effect on exposure, the shutter speed changes the way movement appears in photographs. Very short shutter speeds can be used to freeze fast-moving subjects, for example at sporting events. Very long shutter speeds are used to intentionally blur a moving subject for artistic effect.