A selective focus image is a technique employing shallow depth of field through the use of a wide aperture so that the properly-focused subject is isolated from its surroundings because the surroundings are purposefully not in focus.

The technique is often used in situations where the background would be distracting if it was sharp. Some of the ways to render an out-of-focus background are to use wide-open apertures, long lenses, get the main subject away from the background, move closer to the subject, and change your image-making angle. The purpose is to render a sharp subject or section of a subject immersed in a wash of color. It allows the subject to pop off the page, so the viewer zeros in on the area that's sharp.