Eliminating RBT mount glare (was Re: Summary of stereo slide mounts)

[P3D Paul Talbot <ptww@xxxxxxxxx>]

Greg Erker wrote to DrT:

>   You graciously didn't mention the glare off the
> bevelled window edges, even though I know it bothers
> you too.

I have seen glare off the shiny aluminum of Albion mounts also.
Although glare is not as bad with Albions, it is not exclusively
an RBT problem.  Apart from the glare, however, some people don't
like the thickness of the stereo window formed by the RBT mounts.
  
>   I only do viewer viewing (no projection) so this
> glare is a major detractor for me. I wish RBT would
> rough up the bevels in the mould and fix this
> problem.

There is another way!  In my last order of RBTs, I ordered
one box of "RBT--Glassed" mounts.  I was surprised to learn
that when using RBTs and the anti-newton glass, you use non-
matching mount halves.  I thought Jon Golden had messed up
my order, but he kindly explained for me:

> Here is how the glass works...the glass slide system uses a universal
> full frame white halve to house the glass for all five of the RBT
> openings from half frame to full frame...look carefully at the white
> halve...and see that there is an indentation channel around the
> perimeter of the full frame....to flush house the piece of glass for
> left and right sides.

So for Realist format slides, you have a full-frame white half and a
5P black half.  You mount it so the white is forward in the viewer,
and toward the light if projecting.  When you look at the slide in
the viewer, the bevel of the white half is set back away from the
actual image, and the stereo window is formed by the non-beveled
inside edge of the black half.  Result: crisp, sharp, thin window!!
No thick beveled surface to cause glare!

When using regular RBT mounts, I don't like the way they look in
the viewer with white forward.  However, glassed RBT mounts look
fine with the larger-aperture white half forward.

(The down side is the glassed mounts cost a bit more, and they are
more trouble to work with.)

Paul Talbot


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