Depth of Field

Depth of field diagram

Depth of Field refers to how much of a photograph is in focus. It is an effect specific to photography caused by the shape of lens elements. It is controlled using the aperture, the larger the aperture (smaller the number) the less of the image is in focus.

When we use a small aperture more of the image is in focus than when we use a large aperture. We refer to this as Shallow or Deep Depth of Field. A useful way to remember which is which is large number, large depth of field, small number, small depth of field.