Finding correct Cirkut gears by shooting.

[Leonard Robertson <Leonard@xxxxxxxxxxxxxxxxx>]

I've been told I can find the right gear for a lens (without knowing the
exact focal length), by shooting film at different focus settings, and
picking the sharpest image. As I recall, it is best to shoot something like
a sign where letters "smear" if the focus is wrong. I have Mr. Lipari's
formulas so I can figure the approximate gear as a starting point. I'll be
shooting on 220 film in my #8 Circut, and it seems I can get several short
test shots per roll. Is this idea at all workable, or should I just go
ahead and build a nodal slide to find the exact focal length? If this
method works, any hints will be appreciated. Thanks.
                 																		Leonard