Movement is a condition that a nature photographer must constantly face when making pictures. This motion can occur in several ways. Subjects almost always move, the camera often shakes, the wind seems to move everything, and we move when we hold our cameras. Movement can be both a curse and a blessing.
Science tells us that the absence of motion occurs at absolute zero, or about minus 459 degrees Fahrenheit. Therefore, we warm-blooded photographers need to learn how to either overcome or use the ever-present motion as we snap those shutters!
Motion of the camera when the shutter opens is usually considered undesirable except when we're panning the camera, a topic we'll discuss below. If you want a tack-sharp image, the camera must be still while the shutter is open. A rule of thumb is to not hand-hold a camera at a shutter speed slower than the fraction of 1 over the focal length (mm) of the lens being used. For example, when using a 100mm lens, avoid hand holding the camera at shutter speeds slower than 1/100 second. However, the new vibration reduction/image stabilized lenses can change this rule of thumb and significantly reduce camera shake while allowing hand-held photography at slower shutter speeds.
The 35mm image size captured on film or on a digital sensor is small, about 1.3 square inches. To make an 8x12 inch print, this capture area is enlarged 74 times, and for a 16x24 print it is enlarged 298 times. Even a small amount of camera motion will show up as a blur on larger prints. Some photographers have adopted unique techniques to prevent camera motion, and searching the web to read about these can prove very interesting. Try searching on "camera shake," "blurred pictures," "sharp pictures," and "tripod techniques."
Using a tripod
Most professionals mount their camera on a good quality tripod. The heavier the camera/lens combination being used, the bigger the tripod that is needed. A stiff tripod works best. One quick test of a tripod's suitability is to mount your camera and lens on it and then thump a tripod leg; the camera should not vibrate. When using a tripod, you should not see any camera movement when the shutter is released while you are looking through the viewfinder. Even if you can see no visible movement, there might still be movement you can't see. When using long telephoto lenses (over 300mm) on a tripod, touching the camera and the movement of an SLR camera's mirror can vibrate the camera, causing image blurring. A good way to avoid this unwanted motion is to use a cable or electronic shutter release whenever your camera is mounted on a tripod.
Using a tripod has pros and cons. Pro: When photographing subjects that don't move such as scenics and macros, having the camera mounted on a tripod slows down the photographic process and allows you to study the composition and hopefully make better images. Con: When photographing subjects that move (e.g., running deer, birds in flight), a tripod without a ball or Wimberly-type head will make such photography almost impossible. Pro: A tripod makes multiple exposures and panoramic images possible. Con: You have to carry the tripod!
Caution: Some people position their tripods with the attached camera, and then only make pictures from the spot where they placed the tripod. Professionals, on the other hand, use a quick-release camera mount so they can remove the camera to look through the viewfinder to find the scene and composition they want to capture, and then attach the tripod at the camera's position for the shot.
Using motion effectively
Tack-sharp pictures don't always provide the mood you are trying to capture. A photo showing an object blurred by the wind reveals a different emotion and can be very pleasing. Blurring moving water in a stream also captures its flow. We have found that having something sharply focused in such images provides contrast for the blurred parts and makes a more effective photograph.
If you haven't yet experimented with motion in your images, give it a try. Choose different shutter speeds until you find one you prefer for capturing subject motion. When photographing moving water, I personally like shutter speeds above 1/125 second to freeze the water movement in streams or waterfalls and shutter speeds between 1/4 and 4 seconds for blurred flowing water. Some professional photographers, such as Arthur Morris (www.birdsasart.com), tell you the shutter speeds they use for their great images, and you can use this information as a guide for your pictures.
Moving the camera to follow a moving subject (panning) is also very effective. Panning shows the subject in focus against a blurred background. The camera shutter speed must be fast enough to stop the subject's motion but also slow enough to blur the background. The correct shutter speed depends on how fast you move the camera to follow the subject. Panning is most effective when the subject is moving from side to side in front of you. Initially try shutter speeds from 1/20 to 1/100 second, with the faster shutter speeds being used for the faster moving subjects. When panning, continue following the subject as the camera's shutter is released. Read your manuals to set up vibration reduction/image stabilized lenses and the camera's auto-focus for effective panning. Practice panning with your camera by following a moving subject such as a car.
Motion is important in your photography, either by its absence in a tack-sharp image or by its presence when some element of the image is intentionally blurred. Practice the techniques for both. Those viewing your photographs will appreciate the detailed scenics and the artistic blurs. And your photography will be richer for it!