What is Depth of Field?

Depth of Field (DOF) can be a bugger to understand. DOF could more accurately be called depth of FOCUS since it refers to the area of the image that is sharp. There is shallow DOF where the foreground and background are blurry(soft) or out of focus but the subject is sharp. This puts more emphasis on the subject.  When everything in the picture is sharp as a tack it would be called great or deep DOF. See the difference in the images below.

by Flickr Member Mike Baird

by Flickr Member Alaina Browne