Follow up: vertical 7p/mask chopping

[P3D Elliott Swanson <e3d@xxxxxxxxxx>]

Actually the original post was written to be more or less sarcastic. You
don't really get vertical 7p, just the full height of the 35mm frame, with
a 4p wide image. However, the techniques I described will work if you
actually, for some strange reason, want a full height 4p slr image that
has a close stereo base. (actually a full height vertical half frame 3
image stereo triad is *essential* for cheap lenticular processing if you
want to shoot with a real camera that gives you control over shutter speed
and f-stop, but that's another story...)

Look ma, no tape...  The most important piece of info was mask chopping. 
One of the most tedious job I know is trying to get perfect match of
masking when using aluminized mylar tape to try and block out the
identical area in both the left and right side of a stereo pair. The
simple way is to use Albion masks, cut the top off two of them, and invert
them. Secure the chips in one of the cut mounts, using a gauge to get the
placement of the bottom of the image. I generally flatten the little rib
that holds the chip in the Albions and use a gauge to place the image
(secured into position on one mask section with mylar tape). Then you can
have as narrow an image as you like by sliding the vertical sections of
the mask up or down to lose whatever you want in the image area. A bit of
mylar tape left and right will lock it in and you'll have perfect vertical
and horizontal alignment that will project without incurring death threats
from the projectionist. Practice on a few. It's easy. 

--Elliott


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