Technology and Innovation

DEPTH OF FOCUS — The range through which the image plane (the emulsion of the film) can be moved backward and forward with respect to the camera lens such as defined under the depth of field and circle of confusion. This term is often confused with depth of field and vice versa.
In common English. Depth of Field is what the photographer is interested in; it is what is in acceptable focus in front of the lens. Depth of Focus is what only a technician is interested in; it is what is in focus behind the rear lens element which the film or image sensor “sees.” Kerry Lee