Using depth of field
Depth of field is the range in front of and behind the point on which the lens is actually focused which also appears In sharp focus in the photograph.
It has the following features:
1)The smaller the lens aperture ("F" stop) the greater the depth of field.
2)Wide angle lenses have greater depth4.butkus.org
3)Depth of field behind the point of actual focus (away from the camera) is greater than depth of field in front (towards the camera). It is possible to render the background and foreground in focus (a great depth of field), by using a small aperture, or to blur the background whilst keeping the subject in focus, using a larger aperture.