P3D Terminology

["Donald Wratten" <Wratten@xxxxxxxxxxxxxx>]

Recent posts on the relative merits of 41x101 and 2/50x50 slide mount
formats prompt me to break my habitual silence and throw the following
small offering about terminology into the pot.

During the present year I have been revising - updating and simplifying -
the standard stereo photography glossary, which was originally produced by
the late Bill Dalgoutte (then General Secretary of the Stereoscopic
Society) in the 1960s; published as an international standard in the ISU
journal 'Stereoscopy'; converted into a three-language version by the late
Fritz Waack (Germany) and Pierre Tavlitski (France); and more recently
adapted and extended in the USA by Craig Daniels and Dale Hammerschmidt.

My revised draft has been published in instalments in this year's editions
of the Stereoscopic Society's Journal, and I am now inviting comments from
all readers in the hope that we can arrive at a final version which maybe
can be presented at next year's council meeting of the International
Stereoscopic Union as an updated text for international use.

One of the small issues outstanding is the practice of using the term
'Realist format' to describe both (correctly) the camera film format of
24x23 mm originally devised for the Realist camera and (incorrectly) the
stereo mount with dimensions of 41x101 mm.    [Incidentally, the standard
convention for quoting dimensions is height first, width second and depth -
where present - third; so 41x101 is correct and 101x41 is incorrect.]

To the best of my knowledge, there has never been a term to identify the
41x101 mount size other than by its dimensions - maybe because it is only
in recent times that the 50x50 size has emerged as a serious rival and
therefore the need for an identity has become important.     It is my
understanding that Seton Rochwite, the designer of the Realist camera
system, arrived at the mount size by cutting the then standard glass
quarter-plate size of 3º x 4º inches in two lengthwise.   Therefore, in
honour of its inventor, I am now proposing that the 41x101 mount size
should be identified as the <Rochwite mount>.  This could be contracted in
use to <R-mount> (which would also meet the needs of anyone who feels the
need to continue to refer to it as a <Realist mount>).

I floated the suggestion at last month's AGM of the PSA Stereo Division,
and it seemed to meet with approval.   However, before incorporating it in
my draft I would welcome any comments from members of this group;
especially from anyone who might think it inappropriate.

Don Wratten
President, The Stereoscopic Society


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