Mounting jig - Reply - Part I

[P3D Dr. George A. Themelis <fj834@xxxxxxxxxxxxxxxxxxxxx>]

Brenda Nowlan asks:

>Here is a question I am a little embarrassed to ask this far along in
>the game, but here goes. . .  What is a mounting jig?  I have been
>mounting my slides using only a light table, film cutter, and sometimes
>using gauges from Reel 3D...

Here are a few more embarrassing questions:  What is a light table and what
is a gauge?  I am asking because I don't use any of the two and I don't
think there is much need to use those, provided that the pictures are taken
with a regular stereo camera and are mounted in reasonably accurate stereo
mounts.

I mostly use Albion or RBT mounts, but know people who do the same thing
with cardboard heat-seal mounts.  In the Albion mounts I just position the
chips centered and pushed down.  I then freeview or preview (in a viewer)
the results and slide the chips horizontally to adjust the stereo window or
use a pair of twizers to make small adjustments.  I pay attention to the
edges.  I use the bottom edge of the mount and make sure that the images
are aligned.  If the two chips are aligned at the bottom then they are also
aligned at the top (assuming matching lenses and accurate mounts).

There are no alignment problems when I use my Realist cameras.  The only
adjustment is the spacing of the chips that affects the stereo window. 
Both Albion and RBT mounts allow you to change the spacing of the chips. 
Cardboard heat-seal and slip-in mounts do not leave you with much room for
such adjustment but there is a little bit of play, or you can trim the
chips slightly to get more room.

The problems start when a single (handheld) camera or twin cameras are
used.  The two chips might be rotated or vertically offset with respect to
each other.  The lenses of the cameras might not match in focal length. 
Also, mounting is more complicated when mounts are used that don't have
alignment guides (like the "Spicer" cardboard mounts).  For these cases
some kind of mounting system might be required.  A light table, mounting
gauge and a viewer might be needed to make sure that the alignment is
accurate.  

By "mounting jig" we usually refer to a system that has a light source
(like a small light table), a mounting gauge, a viewer to view the mounting
process and some way to adjust the two chips during mounting.  Some people
have made their own mounting jigs and I think Joel Alpers will soon have
mounting jigs made by Steve Spicer to mount slides in "Spicer" mounts.

To be continued... -- George Themelis


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