Pan blurs are one way to add the energy of motion to an image. Caribou, Alaska. 800mm, 1/30 second at f/14, ISO 80
Most of the time photographers use shutter speeds fast enough to completely freeze the action of their subjects, yielding crisp, sharp images. But intentionally using slow shutter speeds to show motion blur can produce stunning images that imply motion in an aesthetically pleasing way—artful and impressionistic even. Motion blur can be the result of subject motion, camera motion, or both. There is no single formula that works every time for this kind of shooting, and making good images requires taking a lot of photographs and experimenting. Including motion in an image gives it a lifelike feel and a strong sense of energy. Compared to freezing every feather tack-sharp, movement makes a strong impression. In a still image, it is conveyed by blurring— of parts of the subject, of the background, or combinations of these.
In this image of two male Greater Prairie-Chickens fighting on a lek in South Dakota, I added motion to the image by using a shutter speed that rendered the head and body of the birds in sharp focus while blurring the wing tips. 300mm, 1/500 second at f/9, ISO 400
IMPLIED BEHAVIORAL MOTION
Birds in motion often look best when a part of their body is allowed to blur and show the movement. To accomplish this, use a shutter speed that freezes most of the bird but doesn’t freeze the parts of the bird that are moving most rapidly—usually the wings or just the wing tips. This can work with either a bird in flight or a bird on the ground. Choosing the right shutter speed depends on how fast the wingbeats, or other movements of the bird, are. A good starting point is around 1/125 second for larger birds with slow wingbeats and 1/500 second for smaller birds with rapid wingbeats.
Getting the shutter speed just right to imply motion and framing the subject perfectly takes patience. When you have a subject that is repeating a behavior, say a prairie chicken displaying on a lek, get a good round of behavioral images with a shutter speed that freezes all motion first so you have them in the can. Then move on to experimenting with the less predictable but more desirable results that require slower shutter speeds.
In this pan blur of an eagle streaking in for a landing there is enough definition in the subject to give it meaning though most of the image is blurred by motion. Bald Eagle, Alaska. 400mm, 1/30 second at f/4, ISO 800
Creating impressionistic pan blurs, where both the background and most of the subject’s movements are blurry, is very challenging. The photographer uses a slow shutter speed while following a subject that is moving rapidly in one direction. The trick to making successful images is to pan so smoothly and accurately that at least part of the subject, usually the head and eye, are sharp or give the impression of sharpness. This means keeping your subject framed as precisely as you can throughout the pan, which is easiest when you have subjects moving at a constant rate parallel to your position.
The shutter speeds you use for creating pan blurs depend on the lens you use, your distance from the subject, the subject’s velocity, and the effect you are aiming for. In general, the farther away a bird is, the slower the shutter speed you will need. For more distant birds, start with 1/8 second and go from there. For fast subjects flying close by, start with 1/60 second. Remember that the slower the shutter speed you use, the more difficult it will be to get some sharpness where you want it. As with any birds in flight, remember to follow through and concentrate on your framing when you start firing off images. A leveled tripod with a gimbal or video head can help you pan more smoothly than hand-holding, because you can maintain a steady vertical axis and concentrate on only the speed of your pan. Shooting pan blurs is always a matter of volume. Most of the images you shoot will head straight into the trash, but every now and then, everything comes together for a beautiful image.
Groups where some birds are in motion and others aren’t provide good opportunities for more impressionistic images. I photographed this roosting flock of Red Knots in England using a variety of different shutter speeds to see what kinds of images would result. 500mm with 1.4x teleconverter, 1/5 second at f/25, ISO 400
Another way to use motion creatively is to shoot a scene that contains both moving and still elements in the frame. Imagine a Black-crowned Night-Heron standing stock-still on a rock and peering into a fast-moving stream searching for prey. Because the heron is so still, you can use a shutter speed that will render the heron and the rock perfectly sharp but resolve the water into a soft blur. Try a shutter speed of 1/15 second, or slower depending on the speed of the water. Flocks of roosting birds can provide opportunities for this approach as well. Often many birds in a flock will be standing motionless while others are busy preening. Use a shutter speed that freezes the motion of some individuals while showing motion in others.