Depth of field
Depth of field (DOF) is the distance in front of and beyond the subject in focus that appears to be acceptably sharp. Only the subject with the focus on it will be perfectly sharp but some area in front and behind can be considered acceptably sharp. The depth of field range from less than a millimetre to infinite depending on the lens and aperture used.
DOF depends on the aperture value and the sensor size. A camera with a smaller sensor will have deeper DOF.
Shallow depth of field
A shallow depth of field is achieved by using a low aperture value. This is commonly used to isolate the subject from the backgorund and for artistic purposes.
Deep depth of field
A deep depth of field is achieved by using large aperture values. It is common for landscape photography to get a good even sharpness. It is often necessary to use a tripod because of the long exposure times and to make sure the sharpness is not ruined by camera movements.
