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Depth of field
What is depth of field?
Depth of field (DoF) is the range of distance in a scene that appears acceptably sharp. Anything nearer or further than that range looks blurred.
A shallow depth of field isolates a subject against a soft background. A deep one keeps the foreground and the distance sharp together.
What changes depth of field?
Three things control it: the aperture, how far away the subject is, and the focal length of the lens.
Lens aperture (f-stop)
- A smaller aperture, meaning a higher f-number, increases depth of field.
- A larger aperture, meaning a lower f-number, decreases it.
At f/11 much more of the scene is sharp than at f/2.8, with everything else unchanged.
Distance from the subject
- Focusing further away increases depth of field.
- Focusing closer decreases it.
A subject 20m away has a far deeper depth of field than one 1m away, at the same aperture and focal length. This is why close-up photographs have so little in focus.
Lens focal length
- A shorter lens increases depth of field.
- A longer lens decreases it.
A 200mm lens gives a shallower depth of field than a 100mm lens, at the same aperture and subject distance.
Calculating depth of field
To estimate the depth of field for a particular lens setup, use the calculator below.
Depth of Field of roughly 38mm
mm