Depth of Field | Digital Food Photography

Depth of field refers to the area seen by the camera lens within which objects are in focus. Narrowing the depth of field can improve the composition of a picture because your view is limited to just what the photographer wants you to see. This technique directs the viewer's attention to what is sharp, using other, out-of-focus elements to complement the subject, add visual interest, and provide a softer, warmer feeling to the photograph. Sometimes, even a mistake in the background can look good when it is shot at a low angle and thrown out of focus!

The three factors that determine an image's depth of field are as follows:

The f-stop used. A wide f-stop, such as f2, 2.8, 4, or 5.6, gives you a shallow depth of field, with less area in focus. Conversely, a smaller f-stop, such as f11, 16, or 22, allows you to get more area in focus.
The type of lens (normal, wide angle, or telephoto) used. A telephoto lens using the same f-stop as a wide-angle lens will have less depth of field. Because a wide-angle lens has a wider angle of view, more is in focus. It is easier to achieve selective focus with telephoto lenses because they have less depth of field.
The distance from the camera to the subject. All things being equal, there is less depth of field when the camera is focused on a subject that is close to it than when it is focused on a subject farther away.

In addition, shooting at a low angle can provide more depth in a photo. Because a greater front-to-back distance is visible in a low-angle photo, backgrounds will be out of focus if they are farther away.