Getting out of Auto: Understanding Shutter Speed
We've already looked at the importance of understanding ISO and aperture if you want to get your camera out of its automatic setting and start being more creative. Here we'll explore what shutter speed is, how it's measured, and how you can use the setting to take the sort of images you want, and start getting creative with your photography.
What is Shutter Speed?
Compared to ISO and aperture, shutter speed is a relatively straightforward concept to understand. It's the period of time that a camera's sensor (or film) is exposed to light after you hit the shutter button to take a photo, though the way this is achieved can vary slightly depending on the type of camera you are using.
In a DSLR this is done with the mirror flipping up before a shutter curtain opens and closes to control exposure to the image sensor. In a mirrorless or fixed lens camera shutter speed is typically controlled by a mechanical shutter curtain or an electronic shutter, which uses software rather than relying on physical mechanical movements.
How is shutter speed measured?
When selecting the shutter speed on your camera, which is typically done via a physical dial or in menu settings, you're telling the camera how long to expose the image sensor for. If you are not sure what to look for, have a peek at our guide to understanding the buttons and dials on your camera, or your manual. The setting is expressed normally as fractions of a second, like 1/500 (1/500th of a second), 1/15 (1/15th of a second, or 1/2 (half a second).
Most cameras with a manual setting mode will allow users to select from a wide range of shutter speeds. This typically ranges from around 30 seconds at the slow end, to about 1/4000 of a second if you want to shoot with a fast shutter.
What does changing shutter speed do?
As you'd expect, if the shutter is open for longer, more light reaches the image sensor. While this means photos taken with slower shutter speeds will be brighter, it also increases the chances of images suffering blur caused by the subject or camera moving while the image was taken. Equally, images taken with faster shutter speeds are better for freezing motion, but will also be darker as not as much light will make it to the sensor.
Joining aperture and ISO, shutter speed is the final piece of the exposure triangle puzzle, allowing photographers to balance settings to adjust exposure and create the images they want to take. While we'll look at the exposure triangle in more detail in a later article, for now we'll focus on how shutter speed can be used in isolation.
What is a standard shutter speed?
Many photographers consider around 1/60th of a second as a standard shutter speed. However, in truth there is no such thing as standard, as it's always going to depend on what subject you are shooting, in what lighting conditions, and how you want your photo to look. It also has to be considered in conjunction with your ISO and aperture settings. The reason 1/60 sec is a common starting point is because at standard focal lengths and in common lighting conditions it will be quick enough to freeze popular subjects.
Using faster shutter speeds
There are a number of situations where you will want to opt for a shutter speed faster than 1/60th of a second. The most common one of these is when you are shooting a fast moving subject, and a shutter speed which is too slow will result in motion blur. For example the image above was shot at 1/1250 sec, while the paint splatter photo below required a shutter speed of 1/1000 sec to freeze it accordingly.
Other times you'll commonly need to go for a faster shutter speed include when shooting at longer focal lengths, where it can be movement of the camera (not the subject) which causes blurry images. The above image of the helicopter and boat was shot at a 100-mm equivalent with a shutter speed of 1/1600 sec. It used to be said that a shutter speed exceeding your focal length was required (as in faster than 1/50 sec if shooting at 50-mm). However, developments in image stabilization are now allowing users to select shutter speed based on the subject rather than focal length.
If you are shooting in bright lighting conditions, or in a studio with controlled lighting, you'll probably also want to go with a faster shutter speed. The above portrait was shot at 1/160 sec.
Using slower shutter speeds
The most common reason to use a shutter speeds slower than 1/60 sec is a lack of available light, where you need it to achieve a correctly exposed image. For example, with the ISO and aperture values selected, it took a 1/6 sec exposure to capture the image above. When shooting at such shutter speeds you need to make sure your camera is steady for the duration of the shot, to avoid camera-shake blur. This is where having a tripod, or image stabilization can be vital.
However, you can't always adjust the shutter speed to make up for a lack of light, subjects which aren't perfectly static will end up blurred if the shutter speed is too slow. While the low light family shot above demanded a shutter speed slower than 1/60 sec, if it was too slow the movement of the subjects would result in blur. As such, the shutter speed was only slowed to 1/13 sec, with an aperture of F2.8 and an ISO of 6,400 helping to balance the exposure.
In addition to using shutter speed to give well exposed images, slower settings can be used creatively. In the image at the top of this article a lengthy 6 second exposure was used to turn moving vehicles into light trails. Equally a slower than typical exposure of 1/2 sec turned crashing waves above into a smooth blur while keeping the rock sharp, and a 1.6 second exposure allowed runners in a park to appear as a blur in that image.
Hopefully this article has helped give you a basic understanding of what shutter speed is and how it works, along with the confidence to get out there and try playing with the setting to see how it can change your photography.
Shooting in shutter priority mode is a good place to start, as the camera can balance your selected shutter speed with automatic aperture and ISO setting. However, this will see the camera trying to achieve a correctly exposed image, so if you want to get creative with things like light trails and intentional blur you'll want to go with full manual mode.
In an upcoming article we'll look at how aperture, ISO and shutter speed come together in the exposure triangle, and how you can balance the trio of settings to capture different types of image and really take control of your camera.