maofd

[P3D john bercovitz <bercov@xxxxxxxxxxx>]

That's "maximum allowable on-film deviation".  As I mentioned before,
I wrote a spreadsheet and a text describing same and put it in my
anonymous ftp site.  Since then, I have revised the inputs and outputs
and arranged them in a more logical order.  The new version is available
by:

ftp ftp.netcom.com

cd pub/be/bercov/photography/3D/maofd

There's a Mac version in .Hqx and a PC version which needs to brought
down in binary.  Both are Excel spreadsheets.

You enter maximum allowable on-film deviation (from focal length over
30), the focal length of your camera's lenses, the distance to
the nearest object in the scene, the distance to the farthest object
in the scene, and an f/number if you like, and you will see suggested
focusing distance and a few other things like appoximately how fuzzy
the resulting picture will be.  If you like, you can make the spread-
sheet select an f/number for you by equating geometric resolution to
diffraction resolution.  Not strictly correct but it works well enough.
You can also enter a figure for the resoltuion of the film and lens
combination and then add up all the sources of fuzziness in quadrature.
Again, not strictly correct but it gives a reasonably good figure of
merit without doing numerical integrations and Bessel functions and
all that there stuff you probably (and I certainly) haven't used since
college.

John B

PS: It's interesting to use the spreadsheet to compare the resolution
of miniature format to medium format stereo.  They're about equal in
a macro situation but medium pulls ahead in normal use.  This is all
disregarding the considerable advantage medium format viewers have over
miniature format viewers in ease of design and format coverage, of course.


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