Depth of Field in Group Portraits
By: Andrea Ghilardelli

When you are shooting a group of people, you should always make sure to have the necessary depth of field so that important details do not fall out of focus. This is not trivial to achieve. Therefore, you must pay particular attention when using telephoto lenses and when shooting particularly close to your subject, as both cases lead to a reduced depth of field. The same holds true for wide apertures, too.

Which is the most critical group portrait as far as depth of field is concerned? Sure enough, the most difficult is the close-up. If you do not have enough depth of field to focus completely your subjects, it is pivotal that you sharp focus at least the eyes and the frontal planes of all the subjects. This means that the lips and the tip of the nose must be sharp. Ears take second place in order of importance: keep them in focus if you can.

A good photographer knows that the depth of field of a lens is both behind and in front of the point of focus; besides, it is usually greater behind than it is in front. Therefore, it is an error focusing on the nearest part of the subject. Instead, you should focus between the nearest and the farthest points of your subjects, about one third within. In case of doubt, keep it simple and focus on the eyes. This has the additional advantage of focusing on a highly contrasting region (the eyes), making it an easier operation.

As for 3/4- and full-length portraits, it is much easier to focus them properly, as the greater distance from the subject makes the depth of field greater. Anyhow, all the aforementioned recommendations still holds true. If a blurred background is desired, just use a wide aperture.

If many people are involved in a group portrait, it could be taxing to fit all the individuals in the same focusing plane, even in full-length portraits. This is where the skilled photographer takes over and through careful posing of the subject and choosing a good vantage point can expertly accomplish the task.

The theory to work the problem out is quite simple. Just pose all the individuals on the same plane and make sure the camera is pointing perpendicularly to that plane. Easy, isn't it? Unfortunately putting this prescription into practice is a whole other ballgame. The simplest posing strategy is having the individuals in the back of the group lean forward and the people at the front lean backward. This will reduce the depth of field required for a sharp image.

There is a very clever trick to point the camera as perpendicular to the group plane as possible. Your group will typically consist of some people in the front row with their faces lower than the people behind. For instance people in the front row can be crouched and people behind them standing. So, if you raise the camera and point it downward, a better alignment will occur. This, in turn, has the additional advantage of averaging the relative dimensions of the people in the group; otherwise, the people in front would appear larger than those behind.

If your group is very huge, yet another consideration must be taken into account. If you line up all the people in the group in a straight line, those at the sides will be farther away from the camera than those in the center. This is no good, because you want all of them on the same focus plane. So the solution here is to arch the group of people by having them lie in an arc of a circle: let those in the center step back and those at the ends step forward and adjust the others accordingly. All of them will now be at the same distance from your camera, making it easier to sharp focus the entire group.

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