How to Choose the Right Shutter Speed

What Every Shutterbug Should Know
Almost all cameras have an automatic exposure mode to control shutter speed without any manual intervention, but more advanced cameras have overrides to allow you to be more creative behind the lens. If you don’t already, you need to understand a little about how the shutter works and how to best use shutter speed control.

When taking a picture, it’s the shutter that exposes the scene to the film (or the image sensor in a digital camera) making it possible for light to record an image. Without the shutter, you cannot have a working camera.

Depending on the type of camera you own, the shutter is located either in the body of the camera directly in front of the film or image sensor, or in the lens. Shutters are mechanical devices, and are operated when you press the shutter release button to expose the film. In older cameras the shutter is activated by a spring. Electromagnetic shutters are usually more precise, so the newer and more expensive cameras will use electromagnets to activate the shutter.

A camera’s automatic exposure controls will measure available light to decide the correct shutter speed, but doesn’t always make the correct choice in certain lighting conditions. For instance, a subject can wind up being too dark if it is brightly backlit because the available light (including the bright light in the background) is averaged to calculate the correct shutter speed. On many cameras, the automatic exposure mode can be overridden to manually choose a shutter speed.

Shutter speeds are measured in seconds or fractions of a second. The shutter speed progression on your camera might look like this: 1 second, 1/2 second, 1/4, 1/8, 1/15, 1/30, 1/60 and so on, all the way up to 1/4000 of a second, or less. (Shutter speeds can also be more than one second.) The faster your shutter speed, the less time the film or image sensor is exposed, so faster speeds are used for times when there is a lot of movement, to reduce the blur of an object (a runner, a pitched ball, etc.) in the photograph.

Most of the amateur cameras on the market have a focal plane shutter, meaning that the shutter is located just in front of the film. Some professional cameras, will have the shutter mechanism located in the lens, so that each lens has its own shutter with specific shutter speed progressions.

A focal plane shutter works by having two blinds and an open area. When you are not taking a picture, the first blind covers the film, preventing it from being exposed to the light. This blind moves either vertically or horizontally when you take a picture, and is replaced by the second blind. The delay of the second blind replacing the first is the shutter speed, and the flash on your camera is synchronized to coincide with the time gap between the two blinds, so your scene is properly illuminated.

Manually setting the shutter speed can help you prevent blurry and out of focus pictures, but you can alter shutter speed without having in-depth knowledge of shutter speed and exposure. That’s because many cameras have override settings that change the exposure calculation (and thereby the required shutter speed) simply by setting a special exposure mode. Many have features to turn your camera on “night setting” which changes the shutter speed to over one second, or “action setting” which changes the shutter speed to be faster. Consult your manual to find out how these shutter speed settings work on your camera.