P3D Re: Window for Projected 2x2 Slides

[Paul Talbot <ptww@xxxxxxxxx>]

Oleg Vorobyoff wrote:
 
> Hoping this is a suitable question for P3D.

Absolutely!

> What is the recommended way to set the window for projecting 2x2
> slides using dual projectors?

It might depend on how you are projecting (see below).

> I take my slides with a single 35mm
> camera mounted on a slide bar.  The slide bar by default puts the
> window at infinity.  With the RBT 41x101 full frame mounts it is a
> simple matter to diverge the chips to recede infinity behind the
> window. Are there 2x2 mounts available with a 33mm aperture like the
> RBT mounts(instead of 35mm) that will allow the chips to be, in
> effect, diverged?

You can come close.  Try Gepe slide mounts, available in a
wide range of sizes.  Here are some options, with price per
box of 20 mounts:
       Size     Glass     Price    Source
    24x32mm       ?       $7.95     Reel-3D
    24x28mm       ?       $7.95     Reel-3D
    24x28mm      Reg      $4        Joel Alpers
    24x28mm      A-N      $5        Joel Alpers
    21x28mm      A-N      $4.50     Studio-3D

Links:
http://stereoscopy.com/reel3d/mounts-twin.html#gepe
http://www.frii.com/~rkymtmem/mounts/gepe.html
http://studio3d.com/pages2/store_supplies.html

As noted on the Reel-3D page, "GEPE mounts fit all types of
straight, circular and cube slide trays EXCEPT the Kodak
Carousel 140 trays. No glass mounts from any source fit
this size tray."

At the NSA '99 convention, Jon Golden was showing off a new
2x2 plastic mount with pin bar alignment system.  The pin
bars of these new mounts come in many color-coded varieties,
including bars that help correct for rotational error in
twin camera slides.  If I remember correctly, pricing and
availabilty are not yet established.  mailto:3dman@xxxxxxxxxxx
for more info.

> If not, are there any recommended masking procedures?

I've not done 2x2 stereo projection myself.  Perhaps someone
on the list who has can describe their techniques.

> Alternatively, does anyone toe in the stereopair to set
> the window during exposure,

Boris Starosta of this list is known for advocating slight
toe-in.  But he gets a fair amount of argument on that point.

I hope this helps.

Paul Talbot


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