What is shutter speed in photography?

What does shutter speed do on your camera? And, why should you care?

Shutter speed

Shutter speed is the time which the shutter is open allowing in light to your film plane or sensor. Part of the triangle of exposure you’ll want to use and understand once you move past the automatic settings on your camera. “But Bob, I get good photos with the auto setting, why would I want to change?”

Automatic settings get a ‘good exposure’ meaning there will be a readable image when you push the button. Creative images happen when you control specific settings on your camera.

Exposure triangle

We need to poke around in three settings to make a usable photo. What settings? ISO, aperture and shutter speed combine to allow a certain amount of light to be recorded. The aperture is the opening in the lens. ISO is the sensitivity. The wider the aperture opening the faster light can enter. The higher the ISO the more sensitive to light the film or sensor becomes. Shutter speed controls the amount of time the light is allowed to enter.

Change any one of these three settings and another will need to be changed to allow the ‘correct’ amount of light to be recorded. For example, if you make the aperture half as large going from f/5.6 to f/8, you will need to double the amount of time the shutter is open to attain the same exposure if the ISO remains the same.

Let’s be creative

Being in total control of the shutter speed allows for lots of creative control. Look at your control Mode dial. When you choose S on most cameras, or TV (meaning Time Value) on Canon the shutter speed becomes the priority and the other settings work around it.

Fast shutter

Let’s think about some examples of putting shutter speed to work with our vision. Faster shutter speeds in relation to the amount of movement of our subject will give sharp results. Shooting at a fast shutter speed of 1/1600th of a second or faster will freeze large birds wings in flight. 1/125th sec with flash will ensure there is no camera shake when photographing people.

Slow shutter

Slower shutter speeds under a 1/30th of a second can lead to blurry images if the camera is not mounted on a tripod. Changing the shutter to a 1/15th of a second and following the same bird in flight will lead to and artistic rendition with some blur and some in slight focus.

A slow shutter can give wonderful images with intentional camera movement also known as ICM. When attempting ICM it helps to have the camera in motion before the shutter is depressed. Lots of experimentation is called for with subjects, shutter speed and speed with which you move the camera.

Conclusion

Break away from the automatic settings on your camera. Open up tremendous possibilities for creativity in your photographs. Using shutter priority is only one possibility. Once you have figured out the ways to utilize the shutter priority, it will be time to try aperture priority and manual settings as well.