English: This picture shows what photographers call Depth of Field. It is the fact that when taking a picture, the focused zone will extend more or less depending on the aperture of the diaphragm : the smaller the diaphragm, the longer the DOF (i.e., the longer the zone which will appear focused). Of course, this depends on the capture support used; with a very grainy film, the DOF will be bigger than with a slower film (the point being that the blurriness must be smaller than the grain).