Lesson 5: using shutter speed

Exposure = ISO + Aperture + Shutter Speed.

We’ve learned that aperture controls the amount of light coming in through the lens. Shutter speed controls the amount of time in which light is allowed to reach the sensor. (Coming tomorrow: ISO lets you control how sensitive your sensor is in reacting to that light.)

We’ve also learned that shutter speeds should generally be equal to or faster than the focal length of your lens if you are handholding your camera. So keeping that in mind, take a look at your lens, make note of your focal length, and then look at this shutter speed chart, paying particular attention to the sweet spot setting that corresponds with your focal length.

Whereas aperture is determined by the lens, shutter speed (and ISO) is determined by the camera body. Shutter speed is literally the speed in which your camera body’s shutter opens and closes during exposure.

Shutter speeds are measured in fractions of seconds. 1/2 is one-half second, which is pretty fast in general terms but actually pretty slow for a shutter speed. 1/8000 of a second is pretty fast in general terms and in photography.

Shutter speeds are important when you’re trying to show action, either by using blur to show movement or by freezing action.

For example, look at the difference I made in these two photographs of my son simply by paying attention to my shutter speed (and then adjusting my aperture accordingly until my meter said I had enough light):

In the top photo, I froze the action with a 1/1000 of a second shutter speed; it sort of looks like we were just sitting around on some playground equipment because the shutter was much faster than the action. Technically, it’s correct — any camera on program (or auto) mode could have taken this shot.

But a camera on program mode doesn’t always capture the truth or the flavor of an image. That’s the photographer’s job. In this case, changing the shutter speed to 1/15 of a second made the image unmistakably, dizzyingly merry-go-round.

Then for sport I shot two frames at the exact same settings, simply to illustrate the relationship between shutter speed and action. If there’s action you wish to freeze, a fast shutter speed is a requirement. But if there’s no action, the fast shutter speed is hardly noticeable.

 

In the first image, it’s the frozen action that the image is all about. A fast shutter speed is required for this. The second image, shot with the exact same settings as the first, is all about depth of field, and depth of field is controlled by…

Bueller? Bueller? Anyone? Anyone?

Aperture!

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