DOFMaster LE - Depth of Field Calculator

for Palm OS® platform

Circles of confusion for digital cameras

DOFMaster LE makes it easy: only three taps to set aperture, focal length, and focus distance.

Tap on the scale to set focus distance. Tap the 'Hd' button to set focus distance at the hyperfocal distance.

description of elements on main screen of DOFMaster LE

Use the menu to access other screens

Modify the lens focal lengths shown on the main screen

Select the film format

Edit the circles of confusion for each film format

Set the location of infinity on the distance scale

Restore lens focal lengths and circles of confusion to default values

Hyperfocal distance, near distance, and far distance are calculated using the following equations (from Greenleaf, Allen R., Photographic Optics, The MacMillan Company, New York, 1950, pp. 25-27):

Hyperfocal distance:

hyperfocal distance equation

Near distance of acceptable sharpness:

near distance equation

Far distance of acceptable sharpness:

far distance equation

where:
H	is the hyperfocal distance, mm
f	is the lens focal length, mm
s	is the focus distance
D_n	is the near distance for acceptable sharpness
D_f	is the far distance for acceptable sharpness
N	is the f-number
c	is the circle of confusion, mm

f-number is calculated by the definition N = 2^i/2 , where i = 1, 2, 3,... for f/1.4, f/2, f/2.8,...