Controlling the background
Controlling the background is vital to certain types of photography. There are of course times when we want everything in focus. Maximum sharpness in the foreground, middle ground and background is the goal of traditional landscape photography. However, with close-up and wildlife photography, the vast majority of the time we’re trying to photograph a subject against a soft, unobtrusive background.
It’s important to eliminate background “clutter”, so that the viewer’s eye is drawn to the subject. In a photo with a single dominant subject, too much sharpness in the background can be distracting. The eye tends to wander around the image, not knowing where to settle.
There are basically two ways to control the background. One is by altering the angle of view. The angle of view, in simple terms, is the total area of a subject that appears in the viewfinder. Lets say you’re photographing a mountain range using a 28mm lens. When you look through the viewfinder, you’re likely to see several peaks, along with quite a bit of the middle and foreground. If you compose your image a second time from the same position, this time with a 300mm lens, you’re going to see less – a single peek, instead of many. It will appear larger in the frame, and much of the middle and foreground will be missing. By using longer focal lengths, we can narrow the angle of view, thereby making it easier to isolate a subject against a portion of the background containing the least amount of clutter.
The second method of controlling background clutter is depth of field(DOF). Several factors affect DOF – among them, aperture, distance from the subject, and camera sensor size. Large apertures equal shallow DOF, while smaller apertures offer greater DOF. The closer one moves towards a subject, the shallower the DOF. Smaller camera sensors, such as those in compact point-and-shoot cameras offer large DOF, while large sensor professional cameras have the to ability to render images with extremely shallow DOF.
Lets look at the two images below, to see how changing the aperture affects DOF…
In this first image, the aperture was set to f/18. Notice how the discernible detail in the background tends to pull your eye away from the main subject, the two buds which are just beginning to open.
Here, the aperture was set to f/3.2. In this image, the background seems to melt away into a soft blur. The eye is immediately drawn to the sharply rendered buds.
Controlling the background can really make your subjects “pop”, helping you to create eye-catching images.