Re: MOUNTING

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

>George Themelis feels that mounting is simple, and that by practice,
>one can get it right.  This is easier to do with slides than with
>prints...

I am not so sure... In principle, it is easier to mount prints than 
slides simply because the prints are larger.  

But, if you are dealing with slides coming out from a good (meaning 
w/matching and aligned lenses) stereo camera then the job of mounting 
slides in conventional mounts is very easy, simply because the images are 
already aligned.  All you need to do is to put them properly in a frame.

I really don't see what the big deal is regarding mounting.  There are 
only two principles:

- The two images must be vertically aligned.
- They must have an appropriate horizontal spacing.

How do you make these principles reality, depends on your images and 
your choice of mounting material.  I use a good (aligned, etc.) Realist 
and Albion mounts.  All I need to do is push both chips down and they 
are automatically vertically aligned.  If the images come from 
mismatched or misaligned lenses then you might need a mounting gauge.

The spacing of the images in relation to the frame (mask) will set the 
stereo window.  That's something learned by experimentation.  There are 
two schools of thought:  One says the images must be placed with a 
constant infinity separation.  In practice this means that they must be 
centered in the masks.  The EMDE masks with the tabs will let you do 
just that.  The other school prefers to mount "to the window".  In this 
case the separation of the images varies so that the closest object is 
close to the stereo window.  Having a mount with channels, or some 
degree of freedom in moving the images horizontally, helps achieve that.

This sounds more complicated that it really is.  With my good Realist 
images and "window" philosophy all I have to do is put the two chips in 
the Albion mounts, push them down to align vertically and then eyeball 
to move the chips horizontally and bring the closest object to the 
window (or wherever I want it to be).  I look through the viewer and 
might make one or two minor adjustments before I tape the chips aligned 
for life.

I find mounting extremely simple.  The idea behind it can be summarized 
in half a page.  After that it is only a matter of practice to mount 
properly a specific type of images in a given kind of mounts.  

Am I missing something?

George Themelis


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