Shutter speed

• also known as exposure time
• is the length of time when the film or digital sensor inside the camera is exposed to light.
• shutter speed in conjunction with the aperture and the scene's luminance determines the exposure value.
• multiple combinations of shutter speed and f-number can give the same exposure value.
• shutter speed changes the way movement appears in photographs.

          1) Very short shutter speeds can be used to freeze fast-moving subjects.
               Example: A bubble popping

 

          2) Very long shutter speeds are used to intentionally blur a moving object for effect.

               Example: Stars moving in the night sky

•  There is an agreed standard for shutter speeds.