Wide aperture has always been identified with “professional” photography. It is also what separates photography from other arts – defocused backgrounds are a not-so-obvious part of human vision. The lens brought this to our consciousness.
Defocused backgrounds highlight foreground subjects. They lend a pleasing, surreal feeling to images. But in photography, as in life, you give something to get something.
Depth of field can cut both ways. It is on one level an artistic choice, and on another a technical one. There are side effects to choosing to keep it narrow or to go deep.
In the case of wide aperture photography, depending on lens selection and camera-to-subject and subject-to-background distances, your plane of focus can be very narrow. This does not help when you’re shooting a group, for example, and the group is not entirely parallel to camera and in the same plane. In portrait photography, when shooting with even a short telephoto, if the head is turned one eye can be in focus and the other not. I don’t particularly like that look.
However, with small aperture photography, again, depending on the above conditions, your plane of focus can be very deep – extending, apparently, to infinity. So cluttered backgrounds can detract from your subject. On the plus side, keeping foreground elements in sharp focus could be critical to the success of an image. Your margin for error is much greater, and sometimes you need all of the help that you can get.
Sometimes it just doesn’t matter if the background is in focus or not. On seamless, where there is no background, unless you want focus falloff from within your subject, is one such case. Another is when the sky forms your background.
Composition on location where the background is an integral element of the image can play a key role in determining if you can live with the side effects of small aperture selection. Or not.
Photographing dancers – especially when they are moving – is an instance where deep depth of field can be your friend. I don’t trust autofocus to be able to track effectively (and quickly), so I pre-focus. But, where the dancer ends up may not be precisely where I focused, so some forgiveness is a gift.
Even when not moving, depending on the look I am going for, I might want that crispness that deep depth of field provides. Careful composition is the key to making it successful.
Here are a couple of images from a recent shoot with CooperMorgan Dance at Big Talbot Island illustrating a couple of these concepts.
The first is a group shot of Company members, falling slightly away from camera:
I needed a small aperture to make sure they were all in focus. To keep the background, well, a background, I used key shifting and camera angle to make it so. There’s no question what the foreground is and how it separates.
The second is of Julie:
Note the use of camera angle to diminish background elements that are largely in focus. It is the color and the crispness of both her and the trees that make the image. It doesn’t really matter that the distant shoreline is largely in focus as its relative size – and the water – separate it from the foreground.
Small aperture is your friend when it comes to keeping everything nice and sharp. Let that background fight with your subject, however, and it becomes a hostile beast. Without careful attention to composition, small aperture photography can result in “snapshot” style imagery. That’s not a friend. That’s an enemy.