Shutter speed is the third component of the exposure triangle. If you remember from my previous posts, the exposure triangle consists of Aperture, ISO, and Shutter. These three things work together to give us technical and creative control of our images. In the third part of our ‘understanding your camera settings’ series we’ll be exploring your camera’s shutter, how it works, and how you can use it to your advantage.
Shutter Speed Defined
Shutter speed is defined as the length of time that the shutter is open. This is also sometimes referred to as ‘exposure time’. If you think of the aperture like the iris of your eye, then the shutter is like your eyelid. It opens for a brief amount of time and allows us to control the length of time the camera sensor is exposed to light. By controlling the length of light exposure, we can control the brightness of our image. Selecting a slow shutter speed allows more light to reach the sensor while a fast shutter allows very little.
Measuring Shutter Speed
A camera’s shutter speed is measured in fractions of a second. For example, a setting of 1/60 means the shutter is open for one 60th of a second. Unlike Aperture settings, shutter speeds are pretty straight forward. The higher the number the faster the shutter. Shutter speed settings vary from camera to camera, but generally they range from very fast (1/8000 or more) to very slow settings of 1 or more seconds. Some DSLR cameras have a BULB mode which keeps the shutter open for as long as you hold the button down.
Shutter Speed Settings
Shutter settings generally look something like this, 1, 1/8, 1/15….1/125, 1/250, etc. Doubling your shutter speed will open the shutter for half the amount of time. This halves the amount of light that’s reaching the sensor and is equivalent to a 1-stop change in exposure. To maintain the same exposure in your image you must compensate by changing your aperture by one stop. For example, changing your shutter from 1/60 to 1/125 is the equivalent of changing your aperture from 1/8 to 1/16.
How Shutter Speed Affects Images
Now that we understand the shutter and how it works we can talk about how it affects your images. Increasing the speed of your shutter allows you to freeze motion in real life and reflect it in your photograph. By using faster exposure speeds, you can capture a moving object clearly. The object will appear standing still and will be clear even though it is at top speed. To do this effectively ensure that your shutter speed is set faster than the object you’re trying to photograph.
Long Exposure Photography
You can also add creative blur to your images by manipulating the shutter. By keeping the shutter open longer you can capture the movement of an object and add a dynamic effect to your image. This is sometimes called ‘long exposure photography’ and can create stunning images such as the one below. Just remember to adjust your aperture or ISO settings to compensate for the increase in light exposure when using slow shutter times.
If you’re just getting started experimenting with the shutter and other exposure elements, the following info graphic will give you some general guidelines. Use the table to visualize how all three elements of the exposure triangle work together in harmony. Remember, there’s no set rules when it comes to photography. Using proper technique and lots of practice you’re only bound by the limits of your imagination.