## Depth-of-Field Calculator

 To find the near, far, and hyperfocal distances for a specific lens, enter the focal length (mm), aperture (f/number) and the object distance. The near, far, and hyperfocal distances will be calculated. In addition, a table showing the near and far distances for a variety of aperture and object distance combinations will be created as a handy reference.

Focal
Length (mm)
Aperture
(f/No)
Object
Distance
Near
Distance
Far
Distance
Hyperfocal
Distance
The Depth-of-Field unit of measure is meters  feet.

The formula used were extracted from the references supplied and are given as follows:

The Hyperfocal formula:

 ``` Focal Length of Lens 2 Hyperfocal Distance = ---------------------------------------- Aperature * Circle of Confusion Diameter ```

The Circle of Confusion Diameter:

 ``` Circle of Confusion Diameter = Focal Length / 1720 ```

The Near Distance is found:

 ``` Near Distance = (Hyperfocal*Object Distance) / (Hyperfocal + (Object Distance-Focal Length)) ```

The Far Distance is found:

 ``` Far Distance = (Hyperfocal*Object Distance) / (Hyperfocal - (Object Distance-Focal Length)) ```

Remember when performing these calculations that the focal length and all distances must be in the same unit of measure.

References:

"Mastering Large-Format Depth-of-Field", by Gerry Russell, Mastering Black-and-White Photography, Vol. II (Annual Special #7), Darkroom and Creative Camera Techniques'

"Depth-of-Field of Camera Lenses", Photo-lab Index, 1971

Note: this originally came from http://www.par.univie.ac.at/~bob/photo/DOF.html