Depth of focus (depth of field)
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.
|t||Total depth of focus (m)|
|N||Focal nymber (f-number) (dimensionless)|
|c||Circle of confusion (m)|
|u||Image distance (m)|
|f||Focal length of the lens (m)|