by Ian Terry
Taking pictures of objects in motion is one of the most challenging aspects of photography. It’s easy to end up with blurry photos when trying to balance shutter speeds and apertures with a fast-moving subject. But with practice, you can learn to effectively show motion in your images.
The most common type of action shots are those that completely freeze the subject. This is accomplished by using a fast shutter speed—typically around 1/400 of a second and higher. You’ll find that to reach these higher shutter speeds, though, you need bright light. Freezing a trail runner as she glides over a rocky section of singletrack is much easier in direct sunlight, for example, than in a dark forest. It’s not impossible to freeze subjects in dimmer light, but doing so requires lenses capable of letting in more light—which come with a much higher price tag.
Freezing your subject is great for general action shots, but sometimes it results in a picture that lacks any feeling of motion. Dropping your shutter speed to something slower, say 1/30 of a second, can yield interesting results. With a steady hand, you can capture a sharp landscape but leave your subject looking slightly blurry as they move through the frame. If executed well, the subject will have just enough blur to convey motion, but not be so blurry that they become an unrecognizable wash of color and streaks. Catching that perfect amount of motion blur takes lots of trial and error with shutter speeds. A tripod is helpful, but don’t be afraid to experiment and find how slow of a shutter speed you’re capable of holding by hand.
Perhaps the most interesting type of image that shows motion is done by panning with a subject as they move past. Combining this technique with a slow shutter speed can yield incredible results as the subject remains sharp and their surroundings blur. Perfecting this type of motion blur is difficult, as it requires the photographer to track the subject with their lens and match their subject’s speed at the moment they snap the photo. A sort of balancing act is required as the photographer finds a shutter speed that’s slow enough to create blur but fast enough that they can still accurately track the subject through the entire exposure without straying. It can be helpful to focus on one specific part of the subject. For example, if you’re photographing a runner, concentrate on their head as you follow them with your lens and use the markings in your camera’s viewfinder to guide you.
- Single-Shot Autofocus: Most cameras allow for at least two different types of autofocus modes, with the first being one-shot or single-shot mode. This mode snaps into focus when activated and then stays locked to that area regardless of how you move the camera. This mode is useful when you know your subject will either be stationary or will move into an area you’ve already focused on.
- Continuous Autofocus: The second option for autofocusing is continuous mode, which tracks your subject as long as the autofocus is activated. With this mode you can track fast-moving objects and keep your camera locked on them as they move. This mode always functions best in brighter, more contrasting light. Depth of Field: Depth of field (controlled by your camera’s aperture setting) is an often-overlooked tool for helping retain focus on a quickly moving subject. Increasing your depth of field, done by increasing your aperture to a higher number, will give an image with a greater range of things in focus. In other words, by increasing your aperture, you increase the likelihood that your subject will be within the area in focus.
- Prefocus: One final method for capturing a subject in motion is to prefocus, either manually or with autofocus, on an area that you predict your subject will move into. This technique is useful because it takes away the chance of a mistake by your camera’s autofocus system and allows you to focus on nailing the shot.