Photography Basics… what’s depth of field?

Depth of field (DoF) refers to how much of a picture is in sharp focus in front of, and beyond, the part of the picture you’ve focussed on. You can use it to guide your viewers eye to where you want them to look.

The three main factors to bear in mind are

A) The amount of light entering the lens (measured in f stops on your lens). For example f2.8 is a wide aperture so more light comes through the lens giving less depth of field, whereas f16 is a small aperture so less light comes through the lens giving more depth of field

B) The shorter the focal length of a lens the greater the depth of field appears to be at the same aperture. For example a 24mm lens at f8 will appear to have a greater depth of field than a 300mm lens at f8

C) The further the subject is from the background the more out of focus the background will be

Have a look at pictures 1 to 3 (you’ll see the differences more clearly if you view them on your monitor or rotate your phone to landscape).

You can also use a shallow depth of field to create depth to a picture (No. 4) by throwing the foreground and background out of focus.

If you’d like to know more about this and other aspects of photography there are more details here

Antony