Depth Of Field

Depth of Field (DOF) refers to the zone of apparent sharpness both in front and behind the point where the lens is actually focused. I say apparent because the sharpest part of the image will be the spot (distance) at which the lens is focused. Areas both in front and behind the point of focus that are covered by the DOF may appear clear, but will not be quite as sharp as the point of actual focus.

Of course you would normally select the most important part of the image, your primary focal point and the spot to which you want to draw the viewer's attention, as your focus point. The eyes in a portrait are a classic example.

Did you know that there are 3 factors that control Depth of Field (DOF)? They are as follows:

  • The Focal Length of the lens employed

  • Aperture selected

  • The Camera-to-Subject distance

Glenn Guy