Shutter speed is the critical third piece of the exposure triangle. It works with ISO and aperture to create a correctly exposed image.
Shutter speed is measured in seconds and fractions of a second. The numbers on the camera are typically shown as whole numbers; 100, 250, 500, 1000, and higher are fractions in hundreds and thousandths of a second. Shutter speeds greater than a second are typically shown as whole numbers with quotation marks following the number, 1” 2” etc.
A fast shutter speed is typically over 1/500 of a second, while anything below 1/30 is slow.
WHY USE DIFFERENT SHUTTER SPEEDS?
Shutter speed is crucial for correct exposure and a valuable tool for achieving different effects in photography. A slower shutter speed will allow motion in a photograph to be visible as blurriness, while a fast shutter speed will freeze a subject cleanly, not showing any motion or blur.
We have all seen the photos of cars and motorcycles zooming past, looking fast, as the background is a blur of motion. Speed is obvious. The vehicle may have been moving across the image slowly, the photographer following it with the camera, but the effect is that it looks like it is moving at a blistering pace. This effect is achieved using a slower shutter speed that allows motion to be recorded.
Similarly, a photo of a motorcycle racer rounding a corner, the rider’s eyes clearly visible through the helmet, the bright colors of the motorcycle, and its shape crisply captured with no motion visible, is achieved using a fast shutter speed that stops motion dead in its tracks.
UNINTENTIONAL MOTION BLUR, visible as fuzziness in an image, can happen if the shutter speed is too low to freeze the subject’s motion or if the camera moves while the photographer takes the photograph.
The most common reason for motion blur is a shutter speed too low for the photographer to hold the camera without using a tripod or other support. Many can hold a camera steadily to record an image down to 1/60 of a second, but with shutter speeds slower than this, there is a risk of motion blur even when photographing stationary subjects. For moving subjects, the shutter speed needs to be higher.
Telephoto or zoom lenses can complicate this by exaggerating the motion from camera movement. A good rule of thumb is to use a shutter speed equal to the lens’s focal length. For instance, if you are using a lens at 200mm, the shutter speed should be no longer than 1/200 of a second to photograph a stationary subject without motion blur.
Many modern cameras utilize technology to help stabilize the image. Image stabilization can allow the photographer to control the blurriness that comes from camera movement. It is essential to understand that this vibration reduction technology controls the camera’s movement, for instance, the movement that comes from the slight shaking of a photographer’s hands, not the movement of objects being photographed. This technology allows for longer shutter speeds when the camera is hand-held.
Every person is different. Some photographers can hand-hold a camera down to 1/30 of a second, while others naturally move a bit more and can only hand-hold the camera down to 1/100. Practice and experimentation are the only ways to determine the slowest speed you can hold the camera and photograph without motion blur.
