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Re: ANSI Standards for film holders

Below is the only remnants of the ANSI Standard info that I had.  The ANSI Standard file number is ANSI/PIMA IT3.108-1998 . The old standard was numbered -1988, 1998 superceded the old one.  Go to this page, http://webstore.ansi.org/ansidocstore/dept.asp?dept_id=94  the standard is about the 75th from the top.  They are charging $24 for these now, I remember when they were free a few years ago.

The positioning of the ground glass is the most critical detail in the design. The focusing surface of the ground glass has to be in the same position as the emulsion of the film when a film holder is inserted. The critical measurement (the distance from film emulsion to the surface of the film holder) is 4.8 mm or 0.190".

The ANSI standard for the depth of a standard 4 x 5 inch film holder is 0.197" plus minus 0.007". Most film has a base of 0.007" . When film is loaded in the film holder, the depth is 0.190". This is the measurement used by Sinar cameras.   Wisner cameras use a compromise of 0.192" to allow for wear on the wood and because Tech Pan film, used by some photographers to achieve ultra-sharp images, has a base of 0.004".

     The ANSI standard for 5 x 7 and 8 x 10 inch film holders are as follows (film thickness has not been deducted):

     5 x 7"
     0.228" + - 0.010

     8 x 10"
     0.260" + - 0.016

     These measurements may be checked with a Vernier caliper gauge or a micrometer (available in some hardware stores).
     Venire calipers take measurements to 0.1 mm or less.

NOTE:  I think this is for the 14X17 holder.

Height =19.563" minimum
Width = 15.938"-16.000"
Thickness =0.686" maximum
Depth to septum (T) = 0.320" - 0.016"
The far edge of the raised ledge that fits into the slot on the camera back
is19.288" maximum from the end of the holder where one loads the film. It
should be 0.061" +/- 0.015" high.
The bottom flap (F) is 1.043" maximum.