Basic DSLR Training Depth of Field
In this basic DSLR training Depth of field (DOF) we look at what effect this has on your photographs.
What is depth of field?
In basic terms this refers to the part of the photograph that is acceptably sharp and in focus. This will vary in each photo and is dependent on what aperture you use and the focal length of the lens you are using. You can produce from a shallow depth of field to a deep depth of field.
Have you noticed that some photos have the subject close to the camera and everything behind out of focus? This is shallow DOF; the aperture is set at a low f number f2.8 to around f5.6.
Have a look at basic DSLR training lenses for refreshing your knowledge, but in essence:-
Large aperture = Small f-number = Shallow (small) depth of field
Small aperture = Larger f-number = Deeper (larger) depth of field
What affect does distance control depth of field?
Simply put the closer your subject is to the camera, the shallower your depth of field becomes. Therefore, moving further away from your subject will deepen your depth of field.
However it is not quite as simple as that. DOF is dependent on aperture and focal length. Each lens and setting produces a different depth of field. To help you can now get apps that you dial in the aperture and focal length. You get back a reading that tells you what distance from and too that is in acceptably sharp and in focus. See Digital DOF others are available.
Why have a DOF?
DOF makes the image more interesting. For headshots the subject is in focus and the background is out of focus. This puts the emphasis on the subject by not distracting the viewer’s eye. On the other hand it may be that you want to see the whole picture in focus if it is a landscape photo like a line of trees.