P3D Re: Lens Test?

["William J. Carter, Ph.D." <wc@xxxxxxxxxxxx>]

BobH observes:

>Test targets under a microscope (often with high contrast film) will 
>begin to show differences in lenses or one lens at different 
>apertures.

A simple formula; for you number freaques who may wish to extract lens/film
resolution data from your test targets:

                               R1 x R2
R (Total resolution) = -----------
                               R1 + R2

R (resolution) 1, could be your film, and R2, your lens.

What I find interesting is the interactive relationships between film and
lens. Generally speaking, film is going to be a significant weak link in a
photographic still (where there is no averaging, unlike cinema) system. 


------------------------------