T3D Re: stereo mount dimensions

[john bercovitz <bercov@xxxxxxxxxxx>]

Below is what I found in my desk drawer here at work. Why
am I posting it here instead of sending it to the
Stereoptician?  Because others may have other figures 
and I would appreciate their comments.  I may have errors;
if not, others' comments will indicate how much variability
there is within a brand and model.

I've added OT for mount thickness and EC for edge clearance.
(Thanks Steve Berezin.)  I measured from the top edge of the 
mount down to the top edge of the aperture since mounts will 
sit upside down in projectors and what was the top edge becomes 
the bottom or reference edge.  In hand viewers, it's a little
less critical what the edge dimension is.  In medium format, 
it's always the bottom edge that is the reference since they 
are only used in hand viewers AFAIK.  OH and OW are overall 
height and width.  One should remember that if one tapes a 
mount, OT will increase.

John B

=====================================================================

Mount     F    OH    OW     OT    H    EC    W     S      Mtl    SO

Spicer    7P  41.0  101.1   1.2  23.0  9.0  28.0  61.9   paper  JohnB

Spicer    5P  41.1  100.7   1.2  23.1  9.0  21.6  61.9   paper  JohnB

RBT       5P  41.0  100.8   3.0  23.1  9.0  21.4  61.8  plastic JohnB

Albion*   5P  40.8  101.1 .15/.4 23.6  8.5  21.4  62.2     Al   JohnB

Albion*   7P  40.8  101.1 .15/.4 23.6  8.3  28.0  62.2     Al   JohnB

* Thin aluminum mask only - not a complete mount.  Considerable
variation of EC around mask .  0.15 is the thcikness of the material
and 0.4 is the thickness over the film holder.

=====================================================================

PS: Thanks for the issue reference for the Realist 35 mm FL viewer.


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