Depth of Field

Underwater Photography Tips and Techniques on Depth of Field.

What exactly is "Depth of Field"? DOF is actually the appearance of objects to be in focus within a specific distance range. Perhaps the most important word in the above statement is "appearance", since it is true that until your subjects are beyond the infinity distance for the lens you are using, only one plane can truly be in focus. Therefore DOF actually includes other distances that "appear" to be in focus.

Controlling Depth of Field

DOF is often controlled by closing or opening the camera or lens' aperture to either increase or decrease DOF respectively. Ever notice how a sign in the distance can be more easily read by squinting your eyes? This works the same way as decreasing the aperture size on a camera. The smaller the apertures setting the greater the depth of field in your photograph.

Using Depth of Field

Besides being used to keep more of you subject in sharp in your photograph, depth of field may also be used as a composition element. By shooting a subject with a wide aperture, the areas in front of and behind your subject will be out of focus. This is a great way to clean up an otherwise cluttered background, which may improve the composition of your photograph. It may also draw attention to a subject, which might otherwise blend into a cluttered background.