What effect does a shallow depth of field have in portrait photography?

In portrait photography, a shallow depth of field is used to create an effect where the subject stands out prominently against a blurred background. This is achieved by using a wide aperture, which allows less of the scene to be in focus. The resulting blur in the background helps to isolate the subject, drawing the viewer's attention directly to them without distraction. This approach enhances the emotional impact of the portrait and makes the subject more visually appealing.

A shallow depth of field is particularly effective in portraits because it emphasizes the facial features and expressions of the subject, allowing for greater connection with the viewer. The background remains out of focus and less detailed, which can contribute to a more artistic and professional appearance in the portrait.