Depth of Field
Depth of field is the amount of distance between the nearest and farthest objects that appear in acceptably sharp focus in a photograph. A preferred selection Depth of field ("DOF") in a focused subject in an image can be quite subjective. for example the in the photo to the left the subject in crisp focus is the young boy and the background behind him is blurred and out of focus to create an instant pull towards the boy as he is the main focal point, if the depth of field wasn't there the young boy would not stand out as much from the image and the viewer would look at the background as well and the boy and not him individually