Shallow focus is a technique that uses a very narrow depth of field to keep only the primary subject sharply in focus while rendering the foreground and background as soft blur. It is the opposite of deep focus, which keeps the entire scene from near to far in acceptable sharpness, and is one of the most widely used techniques for directing attention and creating a sense of visual depth in both photography and cinematography.

Shallow focus is achieved through a combination of wide aperture, longer focal length, and close subject-to-camera distance - the three factors that minimize depth of field. The technique creates a visual hierarchy where the sharp subject stands out clearly against soft surroundings, making it immediately clear where the viewer's attention should be directed. In portraiture and character-focused filmmaking, shallow focus isolates subjects from their environments in a way that feels intimate and subjective, as if the camera's attention mirrors the viewer's own focused perception. In product photography and commercial work, the technique creates a clean, high-end quality by removing environmental distractions. The quality of the out-of-focus rendering - the bokeh - is as much a part of the aesthetic as the sharpness of the focused subject.

When prompting AI image or video generation for shallow focus effects, descriptions like "shallow depth of field," "subject in sharp focus against soft blurred background," "wide aperture isolation," or "foreground blur with sharp subject" clearly communicate the intended optical treatment and reliably produce imagery with the characteristic depth separation this technique creates.