of field (what is in focus in your picture and what is not). i get so close that i cannot rely on the auto focus of my camera to decide what needs to be sharp and what will be out of focus. in fact, on this shot in the upper left, if i would have focused on the center of the rain drops, they would have been fuzzy and if i were to have used my auto focus, that is where it would most probably have focused because it needs contrast, by design, to work correctly. 