Shutter speed is one of the most important elements of every image you'll ever take. In this guide, you’ll learn how it works, why it is so important and how to manipulate it to improve your images.
What is shutter speed?
Simply put, shutter speed controls the speed in which the curtain in front of your camera’s sensor opens and closes. When the shutter button is pressed, the curtain opens, and your sensor begins to record the light that passes through your lens until the moment the curtain closes again.
The longer that this curtain remains open, the more light is recorded by the camera’s sensor. So, shutter speed is the length of time that your shutter is open. Shutter speed, together with aperture and ISO, form the ‘exposure triangle’ - the blueprint of every photo taken.
Learn more about the exposure triangle with our dedicated guide here.
How is shutter speed measured?
On the LCD screen on the back of DSLRs, and on dials on the top of mirrorless cameras and film camera bodies, there are numbers such as 1/20, 1/100, 2” etc. These relate to shutter speed settings and are measured in seconds. Where the shutter speed is faster than 1 second, this is shown as a fraction of a second.
So, for example, when the shutter speed is set at 1/4 it means a quarter of a second. If it is 1/1000 it means one-thousandth of a second. Where the shutter speed is slower than 1 second it is shown as a whole number and followed by a “ (i.e., 2”, 3”, 10” etc). Most DSLR and mirrorless cameras allow you to set a shutter speed of up to 30 seconds with the option of setting longer shutter speeds with a shutter cable release.
Why is shutter speed important?
There are four main reasons why shutter speed is such an important aspect of digital photography. Here’s why:
To avoid camera shake
One of the biggest frustrations of photographers is their images lacking sharpness. Often the main reason for this is that the shutter speed is too slow. As mentioned above, shutter speed is the length of time that the camera’s shutter will remain open.
The longer this is, the more difficult it will be to avoid the camera moving or shaking during the exposure. Even the smallest of movements will result in camera shake, which means blurred photos.
With the advancement of in-camera image stabilization technology, cameras and lenses can capture images at lower shutter speeds without causing blur. There are different types of image stabilization technology. But they all help the photographer shoot with a slower shutter speed than is recommended and still end up with sharp photos. This is typically 1 or 2 stops slower (i.e rather than shooting at 1/250s, the photographer can capture a replicable image at 1/125s).
But there is still a limit to how slow you can set your shutter speed and hold the camera. This will vary between cameras and also individuals. But no one will be able to handhold a camera steady at very slow shutter speeds such as 1/30s, 1/15s, and so forth.
The best way to know your limit is to test it out. Shoot the same scene with different shutter speeds to see at what point your image will stop being sharp. You’ll then know your limit and your camera’s, and can ensure that you don’t select a slower shutter speed in the future.
See these examples below:
To capture sharp photos of moving subjects
The other aspect of capturing sharp photos is determined by the subject that you are photographing. For example, a shutter speed of 1/80s is fast enough to capture a stationary object. But if you are photographing a moving object, then your shutter speed will need to be faster in order to avoid blur.
For creative reasons
Sometimes you might want to deliberately lengthen the shutter speed for creative reasons. For example, you may want to capture the movement of someone dancing, or light trails of a speeding car. Or you may want to smooth out the water or sky in your landscape shots.
These require slower shutter speeds and will allow you to capture movement in your shots. This technique is called ‘long exposure photography’ - see the example below.
Further reading on how to photograph long exposures can be found in our dedicated guide here.
To get the correct exposure
Ultimately, shutter speed should be used to get the best exposure settings for each image. So, this also includes the brightness or darkness of the image. A slower shutter speed means more light being captured by the sensor which in turn means a brighter image. Faster shutter speed means less time for the sensor to be exposed to light and will mean a darker image. So, if the image is too dark and needs to be brightened, make the shutter speed longer.
How to select the correct shutter speed
Unfortunately, there are no fast rules or cheat sheets that will cover every scenario. Everything from subject matter to the light in the scene, as well as hand steadiness, will have an impact on the shutter speed.
For example, birds in flight may need a shutter speed of 1/1000s or even faster. But capturing a sharp photo of someone jogging can be done with 1/250s or even a little slower. A portrait can be pin-sharp at 1/80s or slower, and if using a tripod, sharp photos can be captured at 30 seconds or longer.
The next step is about learning about different scenarios and practising taking photos. The more you do this the better you will become at judging how fast or slow your shutter speeds needs to be.
Most cameras will have a semi-automatic setting which is called ‘shutter priority’ (often selected from the dial on the top of your camera). This allows a minimum shutter speed to be set. The camera will then automatically determine the relevant aperture and ISO to help achieve a correct exposure at that shutter speed.
This is a useful setting to select when shutter speed is of particular importance to the subject you are photographing, such as wildlife or sport, like the image below:
Hopefully, you now have a better understanding of shutter speed and why it is so important in photography. My advice would be to err on the side of caution and select a slightly faster shutter speed than you think you will need to begin with.
With experience and practice, you will become better at gauging what shutter speed you will need for each shot.
Images by Kav Dadfar unless otherwise stated.