P3D Re: Double your fun with RBT slide mounts

[Paul Talbot <ptww@xxxxxxxxx>]

Dr. George A. Themelis wrote:
 
> Do I detect some bitterness in the last two sentences?

If you do you are misinterpreting.

> I use RBTs for accuaracy in projection.  Seems that with the blue
> foldover over half an RBT mount, they are not accurate or appropriate
> for projection any more

Please explain the basis for this assertion.

> (if this is not correct, please say so)

The accuracy of the RBT system derives from the precision manufacture
of the mounts and the brilliant pin bar/channel design.  Using a
1/2 cardboard foldover with 1/2 an RBT mount, with pin bars, does
not negate or reduce the precision benefits of the the RBT system.

As mentioned in the original post, the cardboard foldover should be
positioned (and possibly cut smaller than 1/2) to ensure that it
does not extend beyond the top and/or bottom edge of the RBT mount.
Failure to follow this advice could result in the slide not sitting
level in the hand viewer or projector.

As I stated originally, I could be overlooking something, but if so
I haven't yet heard what it is.

> The "less fortunate" can always consider some of the less
> expensive cardboard mounts, like the "Spicer" mounts

I also use the Spicer mounts but I want my best slides to be
mounted in RBTs.  Now with this 1/2 RBT technique I can afford
to start taking more good shots and not have to take so many
poor to mediocre shots that are not worthy of being mounted
in RBTs! ;)  [joke]

Spicer mounts are not conducive to achieving the same level of
precision as mounting in RBTs.  I found that the previously
documented problems with misalignment of the 5P Spicer apertures
made for uncomfortable viewing of projected Spicer-mounted slides.

Paul Talbot


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End of PHOTO-3D Digest 2603
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