As some of you know, I recently restored
a beautiful Folmer & Schwing 7X17 banquet
camera that had been smoke damaged in a
fire sometime in it's life.

The camera was a grand bargain and I'm thrilled
to have it but it only came with one original
Folmer & Schwing holder.  I had 3 S&S holders
from a previous 7X17 camera but they're much
different than the Folmer holders.

I decided to make the S&S holders conform
to the camera instead of vice versa.  That way
I could continue to use my one clean original
holder, and the camera would remain original.

As the project was moving along nicely today,
working with a hand planer I noticed with
just unhelped vision that the depth to the film
plane in the S&S holders sure looked deeper
than in my one original.  Time to set up a
rig to take some measurements.

This in no way is the last word in measuring,
in fact the correct way to do conclusive
measurements would be with a "Starret Last Word"
but this method is fast and plenty accurate
enough to let you know where you're at.

I used a Stanley clamp, some wood clothespins,
a 6 inch rule, and a feeler guage.  I didn't like
what I learned but never-the-less at least now
I know where I stand.

Measuring the ground glass distance from
the locating surface.  This sets my standard

Measuring the film plane in my one original holder.

The nasty gap between reference and film in the S&S holders!

Measuring the difference.  In this case, a
full 1/16th inch!  Untennable difference.

I decided to check my Korona 8X20 back
while I was at it.  Since the Korona has a
removeable back I use the edges of the back
as a reference for both ground glass and film
holder.  Here I'm setting my standard reference
down to the glass.

The film holder in this case is spot on.

Same with a 10X12 back and holder that were
suspect because film I developed just this AM
didn't seem as sharp as I expected.  It was a first
time use.  Again, eyeball and seat of the pants.

But again, the film plane in this film holder is a
full 1/16th inch deeper than the ground glass.

And finally I check my beloved Deardorff!  Set
the standard down to the glass.

And film plane at least in this holder is
spot on.