Depth of focus (depth of field) in relation to the magnification


The depth of focus (or depth of field) is a lens optics concept that measures the tolerance of placement of the image plane (the film plane in a camera) in relation to the lens. In a camera, depth of focus indicates the tolerance of the film’s displacement within the camera, and is therefore sometimes referred to as “lens-to-film tolerance.
The depth of field is the range of distances in object space for which object points are imaged with acceptable sharpness with a fixed position of the image plane.
Due to the image distance (not to be confused with subject distance) that is not easily determined, the depth of focus can also be given in terms of magnification.

Related formulas


tTotal depth of focus (mm)
NFocal nymber (f-number) (dimensionless)
cCircle of confusion (mm)
mmagnification (dimensionless)