P3D Weird reflection/ghosting in Stitz stereo adapter?

[pd@xxxxxxxxxxxxx]

I've recently begun experimenting with a Stitz stereo adapter on a
Nikon FE2 with a 50mm f/1.8 fixed length lens.  The Stitz has two
possible adjustments:

1) There's a ring which adjusts the mirror angles.  Interestingly, the
   first part of the scale for this ring is calibrated in feet and
   meters, and appears to be designed to match the distance to
   subject.  If you keep turning past infinity, however, the
   calibrations appear to correspond to lens focal length (100mm,
   200mm, etc.) rather than distance to subject.

2) There's a knob on top which allows you to widen or narrow the
   septum between the left and right light entrances.  By widening the
   septum, you effectively narrow the openings by masking off more of
   the center (ie, right side of left opening, left side of right
   opening)

The problem I'm seeing is that I get good stereo images for about 3/4
of each half-frame, but the outide 1 perf or so is a double image that
appears to be what should be outside the image area.  For example, if
my subject is '3' in:

    1 2 3 4 5

I try to adjust the mirrors to '3' is centered in each half-frame, and
I can see most of 2 and 4 on either side of it on both sides.
However, on the left side of the left half-frame, I'm seeing a
definite vertical line, like the edge of a mirror, and then '1'.
Similarly, on the right side of the right half-frame, I'm seeing a
vertical edge and then '5'

Adjusting the mirror angles doesn't seem to affect this noticeably.
It seems I can get rid of this by adjusting the septum knob (ie, by
making the openings narrower), but then I get a very wide black band
between the two half-frames.

If anyone's familiar with splitters in general, and the Stitz and/or
Miida in particular, I'd love to know:

1) Is this a common effect?  Am I doing something wrong?  Do I have to
   live with having a huge black band down the middle?

2) Do I need a longer focal length lens?  The manual (which is
   extremely vague on the subject) refers to using 55mm lenses, but
   I'm using a 50mm.  Would those 5mm make a difference?

3) Are there any other sources of information about the Stitz or how
   to adjust it?  The manual is extremely disappointing.  It basically
   shows a couple of pictures of incorrect adjustments, and says
   "adjust it so it doesn't look like these."

Thanks very much for any and all help.

-pd


-- 
--------
                             Peter Davis
               Funny stuff at http://www.pfdstudio.com
    List of resources for children's writers and illustrators at:
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