If you took a poll of portrait photographers to see which shooting mode was most often used for portraits, the answer would certainly be Aperture Priority (A, for short) mode. Selecting the right aperture is important for placing the most critically sharp area of the photo on your subject while simultaneously blurring all of the distracting background clutter (Figure 6.1). Not only will a large aperture give the narrowest depth of field, it will also allow you to shoot in lower light levels at lower ISO settings.
This isn’t to say that you have to use the largest aperture on your lens. An aperture of f/1.2 may be too large, thus creating a shallow depth of field. A good place to begin is f/5.6. This will give you enough depth of field to keep the entire face in focus, while providing enough blur to eliminate distractions in the background. Remember, a portrait is all about the eyes, so focus first on the eyes and recompose the frame if needed (Figure 6.2). This isn’t a hard-and-fast setting; it’s just a good, all-around number to start with. Your aperture might change depending on the focal length of the lens you are using and on the amount of blur that you want for your foreground and background elements.
Go wide for environmental portraits
There will be times when your subject’s environment is of great significance to the story you want to tell. This might mean using a smaller aperture to get more detail in the background or foreground. Once again, by using Aperture Priority mode, you can set your aperture to a higher f-stop, such as f/8 or f/11, and include the important details of the scene that surrounds your subject.
Using a wider-than-normal lens can also assist in getting more depth of field as well as showing the surrounding area. A wide-angle lens requires less stopping down of the aperture (making the aperture smaller) to achieve an acceptable depth of field. This is because wide-angle lenses cover a greater area, so the depth of field appears to cover a greater percentage of the scene.
A wider lens might also be necessary to relay more information about the scenery (Figure 6.3). Select a lens length that is wide enough to tell the story but not so wide that you distort the subject. Few things in the world of portraiture are quite as unflattering as giving someone a big, distorted nose (unless you are going for that sort of look). When shooting a portrait with a wide-angle lens, keep the subject away from the edge of the frame. This will reduce the distortion, especially in very wide focal lengths. As the lens length increases, distortion will be reduced.
There are multiple metering modes in your camera, but the way they work is very similar. A light meter measures the amount of light being reflected off your subject and then renders a suggested exposure value based on the brightness of the subject and the ISO setting of the sensor. To establish this value, the meter averages all of the brightness values to come up with a middle tone, sometimes referred to as 18 percent gray. The exposure value is then rendered based on this middle gray value. This means that a white wall would be underexposed and a black wall would be overexposed in an effort to make each one appear gray. To assist with special lighting situations, the D7000 has three metering modes: Matrix (Figure 6.4), which uses the entire frame; Spot (Figure 6.5), which takes specific readings from small areas (often used with a gray card); and Center-weighted (Figure 6.6), which looks at the entire frame but places most of the exposure emphasis on the center of the frame.