3.2. PortraitsYou may have noticed that in most professional photo portraits, the background is softly out of focus. Unless you have the cheapest camera on the planet, you can create a similar great-looking effect yourself. In photographic terms, a shot with a soft-focus background is said to have a shallow depth of field . The term " depth of field" refers to how much of the picture is in focus. When you're photographing your family in front of the Great Wall of China, you'll probably want a deep depth of field, so that both the people and the background remain in focus. But in typical headshot-type portraits, you'll want a shallow depth of fieldand a blurry background. Figure 3-5 should make this point clearer. So how do you control the depth of field? Here are a few ways. 3.2.1. Trick 1: Zoom InIt might not seem logical that you'd want to use your camera's zoom lens (if it has one) for a portrait. After all, you can get as close as you want to the subject just by walking. But thanks to a quirk of optics, zooming in helps create a shallow depth of field, which is just what you want for portraits. 3.2.2. Trick 2: Move the Background BackThe farther away your model is from the background, the softer the background will appear. If you choose an ivy-covered wall as your backdrop, for example, position your subject 10, 20, or 30 feet away from the wallthe farther, the better. 3.2.3. Trick 3: Choose a Wide Aperture SettingYou may remember that two factors determine how much light fills a shot: how long the shutter remains open (the shutter speed) and how wide it opens (the aperture). In sports photography, what you care about most is usually the shutter speed. In portrait photography, what you care about most is the aperture settingbecause the size of the aperture controls the depth of field. Low-numbered aperture settings like f-2.8 or f-4 are referred to as wide aperture settings by photographers because they let lots of light through the lens. These wide settings also help create soft backgrounds for portraits. Figure 3-5. Top: The trick to creating a soft background, whether for a portrait or a landscape, is to use a large aperture setting, like f-2.8 or f-4. (Quirkily enough, low f- numbers indicate larger aperture settings; see the table in Section 3.2.3.2.) |
f-stop | diameter of aperture | depth of field | background looks |
---|---|---|---|
f-2 | very large | very shallow | very soft |
f-2.8 | large | shallow | soft |
f-4 | medium | moderate | a little out of focus |
f-5.6 | medium | moderate | a little out of focus |
f-8 | small | moderately deep | mostly in focus |
f-11 | small | deep | sharp |
f-16 | very small | very deep | very sharp |
Position your model so the backdrop is in the distance. Check for telephone poles or anything else that may appear to pierce the model's head. If you can, shoot on a cloudy day, first thing in the morning or late in the afternoon; these are the best situations for outdoor portraits, when the light is softer and more flattering. Otherwise, try to place the model in open shade , like under a tree.
Adjust the flash settings so the flash is forced to go off, which will provide a nice supplemental burst of light. Don't stand more than ten feet away from your subject or your fill flash won't reach.
Finally, zoom in and start shooting. You'll notice that if you're standing within ten feet (so the flash will reach) and zooming in as much as your lens allows (to help soften the background), your model's upper body will fill the frame. That's what you want. Unwittingly, most snap shooters stand too far away from their subjects.
After a few frames , review your work and adjust as necessary. The soft background effect probably won't be as strong as it would be if you were using a pro camera with a telephoto lens, but you will definitely notice a pleasant difference.