Technology and Innovation

This cute but weird distinction between the terms Depth of Field and Depth of Focus is amusing but terribly in error. As 1 hope you recognize, Depth of Field refers to the appearance of relative image sharpness in the objects in the scene toward which the lens is pointed. While there are certain generally accepted norms for describing this, there is a lot of room for definition and interpretation.
Contrarily, Depth of Focus refers to characteristics of the projected image inside the camera at the location of the film or digital sensor.

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