Tech Notes

DEPTH OF FOCUS and DEPTH OF FIELD

The terms "depth of field" and "depth of focus" are confused in usage and understanding.  Properly "depth of field" describes how much of the object's depth can be held in reasonable focus from a particular lens or instrument. The term "depth of focus" has traditionally been used to describe how much tolerance of focus there is at the sensor or film plane.

Infinity has correctly adopted the term "depth of field" to describe how much of the object's depth can be held in reasonable focus. Correct usage aside, it can also be read "depth of focus" if reference is being made to the object.