P3D Twin 35mm and Franka slide system

[Alan Lewis <dlewis@xxxxxxxxxxxx>]

Since there has been a lot of discussion lately about twin 35mm stereo I
thought I'd add something that I noticed today while remounting some
35mm full frame single slides for the slip in Franka holders.

I was remounting some slides from GEPE mounts into cheap PAKON plastic
slip in mounts. (BTW; the PAKON slip in mounts are quite nice, very easy
to use and offer some adjustment for windowing and bad alignment).

When I put these slides into the Franka holder and positioned the slides
flush with the outside edges of the Franka holder, I noticed that when
viewing there is some compensation for the infinity stereo window.  I
can definitely notice that a close to proper window is usually present.

It seems that the opening of the Franka holder will mask the right edge
of the right slide, and the left edge of the left slide.  This helps to
obtain the "more in the middle" relationship that is necessary for
making a proper stereo window.  What happens is that the visible image
area is reduced to 33mm width, which is about what is needed to set a
good window with twin 35mm slides.

If you center the slides in the Franka opening (which is the normal
tendency) there is no window compensation.

Is this just peculiar to my setup, or has anyone else noticed this? (Or
am I just inattentive, and you guys have already discussed this)?
-- 
_______________________________________________________________
Alan Lewis
mailto:dlewis@xxxxxxxxxxxxx
Home of the stereo wedding package, and weekend stereo projects
http://www.arlington.net/homes/dlewis



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