What is ‘Shutter Speed’?
1) What is Shutter Speed?
Shutter speed, also known as “exposure time”, stands for the length of time a camera shutter is open to expose light into the camera sensor. If the shutter speed is fast, it can help to freeze action completely, as seen in the above photo of the dolphin. If the shutter speed is slow, it can create an effect called “motion blur”, where moving objects appear blurred along the direction of the motion. This effect is used quite a bit in advertisements of cars and motorbikes, where a sense of speed and motion is communicated to the viewer by intentionally blurring the moving wheels.
Slow shutter speeds are also used to photograph lightnings or other objects at night or in dim environments with a tripod. Landscape photographers intentionally use slow shutter speeds to create a sense of motion on rivers and waterfalls, while keeping everything else in focus. On a very bright day when there is a lot of light, if you allow the shutter to be open for too long then too much light will get to the sensor. When this happens you end up with pictures that are very pale and almost all white. This is known as being “over-exposed”.
2) How is shutter speed measured?
Shutter speeds are typically measured in fractions of a second, when they are under a second. For example 1/4 means a quarter of a second, while 1/250 means one two-hundred-and-fiftieth of a second or four milliseconds. Most modern DSLRs can handle shutter speeds of up to 1/4000th of a second, while some can handle much higher speeds of 1/8000th of a second and faster. The longest shutter speed on most DSLRs is typically 30 seconds (without using external remote triggers).
3) Fast, slow and long shutter speeds
Fast shutter speed is typically whatever it takes to freeze action. For me, it is typically above 1/500th of a second for general photography and above 1/1000th of a second for bird photography.
4) How to set shutter speed
Most cameras handle shutter speeds automatically through in-camera metering. When the camera is set to “Auto” mode, both shutter speed and aperture are automatically selected by the camera. When you shoot in “Aperture Priority” mode, you set the lens aperture, while the camera automatically sets the shutter speed.
There are two ways to manually set the shutter speed: a) By setting the camera to “Shutter Priority” mode (marked “S” on the dial), where you set the shutter speed and the camera automatically selects the aperture. b) By setting the camera to “Manual” mode (marked “M” on the dial), where you set both shutter speed and aperture manually.
Example of slow shutter speed: