Depth of focus (depth of field)
Description
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.
Variables
| 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) |