To sharpen the background of the picture you need to adjust the depth of field (DOF) ; DOF refers to how much of the picture is in focus. It is determined by the distance between the camera and the subject, as well as the focal length and aperture of the lens.
Follow the steps below to adjust the DOF and reduce the amount of background blur.
NOTE: Because each of these steps represents a possible solution to this issue, take a new picture and check the background after completing each step.
- If possible, move the camera farther away from your subject.
- If using a zoom lens, set it to a smaller focal length. Otherwise, use a different lens with a smaller focal length.
- Use a narrow aperture setting (indicated by a higher f-stop number).