Depth-of-field or DOF is the distance between the nearest and farthest subject in your photo that appears acceptably sharp in
your photo. Now that we got the "technical definition" out of the way in plain english that means what is sharp. A shallow
depth-of-field is when your subject is in focus and everything else is out of focus.
In the above photo of a
shallow DOF the Setting were Aperture: f/1.8 Focal length: 50MM Disntance: Aprox. 1 foot
A
wider depth of field is when everything in your photo is in focus, from the background to the forground.
In the above photo of a wider DOF
the settings were Aperture: f/5.6 Focal length: 38MM Disntance: Aprox. 12 feet
The area of
sharpness are controlled by three things:
- Aperture
- Focal length
- Distance from your subject
Now
lets go into detail on how these three factors effect your DOF.
Aperture: or
F-stop number is how much your shutter opens to let in light. The higher the number the less light is let into the camera. When
you have a large aperture number like F22 the photo will contain a large DOF, this is when a large range of your picture is
sharp. when you have a lower aperture number like 1.8, then only a small portion of your image will be in focus.
Focal Lenth: The focal length is the MM number on your lens. The larger the focal length
(higher than 50MM number) The smaller DOF will be. The shorter the focal length(smaller than 50MM number) the wider DOF will
be.
Distance From The Subject: Close up photos have a shallow DOF. if you
shoot landscapes, where the main subject is far away from you have a Wider DOF. In other words, the closer you are to your
subject, the shallower the DOF will be.
In a future lesson I will go though some of the setting on how to increase and
decrease your DOF.
Comment below if you have any questions or to let me how you like these lessons.