Understanding Depth of Field (DOF) is one of the principal concepts for photographers to master in order to expand their capability, and creativity. The following videos present the overall concept and technical explanations of DOF in a concise manner.
DEPTH OF FIELD OVERVIEW
[youtube http://www.youtube.com/watch?v=l3zdybilbCY]
The video below gives a more thorough understanding of how to control depth of field by the photographer’s use of adjusting the aperture, changing proximity to the subject, or changing the focal length of the lens. The video is long, but very worthwhile.
[youtube https://www.youtube.com/watch?v=JpKDJgXqqmw&w=560&h=315]