Zoom Zoom: Shutter Speed

Of all the camera settings, shutter speed is probably the most important when you are zoomed in. Normally, when I’m photographing birds, I use shutter priority, meaning I set the shutter speed I want/need and let the camera adjust the aperture to get the right exposure. The shutter speed is the amount of time the shutter is open and light is reaching your camera sensor (or film). The faster the speed, the more you can freeze motion, either yours or your subject’s.

One rule of thumb is to have a shutter speed the inverse of the length of you lens in millimeters. By this measure, when I’m maxing out my zoom lens at 400mm, my shutter speed should be 1/400th of a second. Some cameras/lenses have image stabilization, which reduces the impact of your movement. This allows you to reduce your shutter speed if your subject isn’t moving.

You can figure out what shutter speed works for you with a little bit of testing. When you look at an image, if everything is blurry, that’s your motion. If only your subject is blurry, that’s probably their motion. Find the shutter speed that lets you consistently take clear photos when zoomed in.

Motion blur caused by camera movement and a slow shutter speed.
Motion blur caused by camera movement and a slow shutter speed.
Motion blur caused by a moving subject, only the fast-moving parts are blurry.
Motion blur caused by a moving subject, only the fast-moving parts are blurry.

If it freezes your motion and the motion of your subject, why not just use a super fast shutter speed all the time? A fast shutter speed doesn’t let in much light, so you need a bright day or you need to adjust your aperature and ISO to get a good exposure. Although the other settings are not necessarily as crucial, they are also important, as we will find out.

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