Shutter speed is a camera setting that often confuses new DSLR owners. It works in tandem with aperature and ISO to determine exposure. In this second post on camera settings for dummies, I’ll be explaining facts about shutter speed, and how to know when to use a fast or a slow one to ensure that your images are properly exposed.
Facts About Shutter Speed
What is Shutter Speed?
Shutter speed is the amount of time a camera’s internal digital sensor is exposed to light. The sensor is the part of the camera that records an image. Shutter speed is measured as a fraction of a second, and is also referred to as “exposure time.” It helps to understand how a camera’s shutter works my comparing it to a set of doors. The wider the doors open, the more light comes pouring in, with the converse also being true. Exposure is dictated by shutter speed, aperature, and ISO.
A shutter speed of 1/30th of a second, which will require a tripod by the way, is an applicable setting for photographing indoors because of the amount of ambient light it will allow to fall onto the camera’s sensor. On the other hand, shutter speeds of 1/500th of a second let in little light, but are amazing for freezing motion, which brings us to another important function of shutter speed. In addition to affecting exposure, the length of time the sensor receives light, also represents how movement appears in an image.
Sports, or any kind of action photography, require fast shutter speeds in order to freeze motion, and to prevent motion blur. Fast shutter speeds are ideal for photographing animals and children, or any subject that could potentially move. Incidentally, flash also freezes motion and dials in focus. Shooting in manual mode, rather than automatic, lets you manually set your shutter speed, aperature, and ISO, giving you ultimate control over image exposure.
Fast Shutter Speeds
The faster the shutter speed you opt to use, the larger the aperature will need to be to compensate for less light hitting the sensor. Conversely, slower shutter speeds enable smaller aperatures, along with more depth of field. The specific settings will depend on how much light is available and what you’re shooting. ISO is also a factor, and is an acronym that stands for “international standards organization.” In the days of film, it was referred to as film speed, and represented how sensitive the film was to light.
In the age of digital photography, ISO is a measurement of how sensitive the camera’s sensor is to light, with higher ISOs being helpful to maintain exposure in poor lighting conditions, as well as allowing additional freedom in setting aperature and shutter speed. However, there are consequences to using higher ISOs, namely grainy photographs, although enourmous improvements have been made in this area over the years.
In the photograph below, a fast shutter speed was used to freeze the movement of the galloping dog. You can tell by the bokeh (blur) in the background that a large aperature was used to compensate for the fast shutter speed.
Slow Shutter Speeds
There is a wide spectrum of shutter speeds, ranging from 1/15th of a second to 1/8000th. The slowest speeds I typically use are 1/15th to 1/30th for long exposures, which are necessary for correctly exposing indoor events or for real estate photography. I’ve never used a shutter speed faster than 1/500th of a second, but use it for freezing motion and compensating for wider aperatures. “Shutter speed priority” is a semi-automatic camera setting that enables you to set the shutter speed, with the camera automatically selecting the aperature based on the lighting conditions.
Slow Shutter Speeds
Longer (slow) shutter speeds are used for artistic purposes, as well as for setting exposure in situations where the lighting is not ideal. Leaving the shutter open for longer periods of time, not only lets more light hit the sensor, but also creates some pretty cool effects by how it impacts motion. My favorite way of using slow shutter speeds (1/15th of a second), as a creative creative technique, is by blurring water.
Slow shutter speeds are also fun to use for time lapse photography because you can control movement during the transitions. Longer speeds result in motions that are much smoother. Another artistic way to utilize slow shutter speeds is by using them in conjunction with panning, a technique where you follow your moving subject with your camera. This technique keeps your subject in focus, while blurring the background.
If you want to get really creative, you can use the “Bulb” feature on your camera to obtain really looooong shutter speeds up to 30 minutes. The bulb feature is often used with a remote control to avoid camera shake, with the shutter staying open until either the remote or the shutter is released.
Decreasing your shutter speed one stop enables you to gain one step (+1) in exposure brightness by doubling the amount of light that reaches the sensor. For instance, changing your shutter speed from 1/60th of a second down to 1/30th of a second, lets in double the amount of light. If you want your image darker, the opposite is also true.
Shutter speed, aperature, and ISO are like three legs of a stool. A correctly exposed image is the result of all three being balanced just as a stool stands upright when all three legs are even. Shutter speed, specifically, dictates how much light hits the camera’s sensor, and how motion will appear in a photograph. Learning how to manipulate shutter speed will give you control over both exposure and motion. It’s worth learning the ins and outs of shutter speed so you can operate your camera in manual mode, which is a lot more fun than shooting in automatic.
Do you have any questions about shutter speed? Let me know in the comments:)