[Leica] Depth of Focus table or calculator

[jsmith342 at cox.net (Jeffery Smith)]

Do any of you know of a depth of focus calculator (not field depth...depth
of focus, i.e., how much tolerance one has in deviations of the film plane
in a camera). It is my understanding that the more wide angle a lens is, the
greater the field depth but narrow the depth of focus. I was interested in
finding out just how flat or just how accurate in distance film had to be to
ensure that the image is focused on the film. My impression is that the
depth of focus is *extremely* narrow in that 120/220 cameras must adjust for
the thickness of paper in the 120 setting.

Jeffery Smith
New Orleans, LA
http://www.400tx.com