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. |
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