P3D Re: Airequipt Theater

["Greg Wageman" <gjw@xxxxxxxxxx>]

From: Arthur Payson <APayson@xxxxxxxxxxxxxx>


>Who has had experience with the Airequipt Theater?  Are they any good?  How
>are the optics, are they mechanically sound, how wide is the viewing area
>(5p/7p/wider?)?  Can the viewing areas be enlarged?


As our resident viewer expert, Dr. T., hasn't yet responded, I'll chime in. :-)

I have a few Airequipts, in various stages of renovation.  The optics are glass
doublets (pairs of plano-convex lenses), which are better than simple lenses,
but not as good as achromats.  However, if you like, they can be fairly easily
replaced with 50mm F.L. achromats from Edmund Scientific or other sources.

Mechanically, they are very solid.  Under the smooth plastic housing, they are
made from two cast side plates which contain the mechanism, which is aluminum
and aluminum alloy.  In my opinion, the only weak spot in the design is the
switch for the light, which is of sheet copper or brass (varies), and must make
contact with two brass rivets on one of the side plates to complete the
connection to the battery.  In practice, these contact points become coated with
grime, and unreliable, producing flickering.  I have supplanted the spring
contacts with a roller-lever microswitch from Radio Shack, which I have attached
to the side plate by drilling holes for screws and nuts.  The roller lever of
the replacement switch is activated by the slide elevator plate when it is in
nearly its fully-elevated position (using the normally-open contact).  This
provides a positive activation for the lightsource.  This modification requires
completely disassembling the viewer, which in turn requires drilling out the
rivets from the handle of the actuator arm in order to remove the plastic
housing.

The viewing arrangement is unique among viewers, in my experience.  When looking
through the eyepieces, one is actually looking down at a front-surfaced mirror,
which is angled at 45 degrees to both the slide and the lenses.  The light
source is actually pointed toward the rear of the machine, through the slide,
and toward the mirror.  Something like this:

    o (eye)
    - (lens)
->|/ (mirror)

The mirror is approximately the external dimension of a Realist slide mount.
There are no internal apertures except whatever is provided by the slide mount.
Thus the only limiting factor is the field of view of the lenses.  It will
definitely work with 7p slides; full-frame is pushing it a bit.

I would recommend that you try to get hands-on experience with one, perhaps at a
flea market, camera show, etc., before you commit to one; on the other hand,
there seems to be a ready market for them, so you can always resell it later if
you decide you don't like it.

     -Greg W. (gjw@xxxxxxxxxx)





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End of PHOTO-3D Digest 2481
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