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.


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. 2527):
Hyperfocal distance:
Near distance of acceptable sharpness:
Far distance of acceptable sharpness:
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 fnumber 
c  is the circle of confusion, mm 
fnumber is calculated by the definition N = 2^{i/2} , where i = 1, 2, 3,... for f/1.4, f/2, f/2.8,...