Compco 500

[P3D Oliver Dean <3d-image@xxxxxxxxxxxxxx>]

> Could that mean that the blower is not as "effective"?  Has anybody had
> any overheating problems with the 500?

I haven't noticed any problems with mine.  The warm air blowing out of
the top of the lamp housing seems to maintain a reasonable temperature
even after an hour of continuous use.  I would never try to convert it
to use 750 watt lamps, however. 
 
> My problem regarding the adjustments is with the vertical alignment which
> is done by pulling a lever up and down.  This creates overshooting and
> makes it difficult to fine-tune the adjustment.  The TDC uses a screw.
 
Yeah, I noticed this too, at first.  But I was used to the TDC and
wasn't prepared for the lever.  After using it for a while, though, I
got used to it and got to like it better than the TDC controls,
especially because the TDC controls are located much more inconveniently
for an operator standing behind the projector.

> >brightness, and uniformity are very good, however, and the polaroids are
> >located where I like them -- between the slide carrier and the lenses,
> >which eliminates the depolarizing film base problem...
> 
> Given how rare this problem is, I am still not sure which is a better
> position for the polarizers.  Sitting behind the slide they offer extra
> protection (polarizers cut up to 2 f-stops of light and radiation)

Yes!  Has anyone experimented with adding "cold" mirrors (they reflect
visible light, transmit infrared heat) or "hot" mirrors (they reflect
infrared, transmit visible light) to a stereo projector in order to
reduce the heat at the slide? I understand that some of the Kodak
flattie Carousel projectors use an angled "hot" mirror to redirect the
infrared off to one side while allowing the visible light to get through
without anywhere near the light loss you get from polarizers. Use of
such mirrors near the lamps, with the polarizers located in front of the
slide carrier, would seem to me to be the ideal arrangement. What do you
think?

Incidentally, the depolarizing problem may not be so rare, but for a
different reason from a Film Base from Hell.  At the Hollywood
International Stereo Exhibition judging yesterday (Saturday -- see next
message), we had a slide that COMPLETELY depolarized the image, to
everyone's consternation.  Examination of the slide showed that it was
in a cardboard mount in a slip-in plastic sleeve protector. The plastic
sleeve protector was the culprit -- as soon as the slide was temporarily
(and laboriously) removed from the tight-fitting sleeve, the slide
projected OK!  So.  Now we have Plastic Sleeve Protectors from Hell!
{:>)
 
> 
> >It is much smaller and lighter in weight than the TDC's, also. 
> 
> Smaller, lighter?  I don't think so.  They look about the same size and,
> having shipped a few in my life, they weigh about the same.  Perhaps the
> 716 might be a bit heavier or bigger, but the 116 is about the same.

Just weighed both projectors (the TDC is a 716, but my 116 in storage is
the same size) without carriers on my electronic bathroom scales (you
can tell I believe in precision instrumentation here! :>) ), and the
Compco 500 weighed in at 18 lbs, while the TDC weighed in at 21 lbs. 
Admittedly, while clearly apparent, it is not exactly "much"  of a
weight difference, and the 116 could be lighter; I did indeed somewhat
overstate the case.  However, the Compco 500 is a more sleek, modern
design, and the maximum exterior height above the table is a svelte 9
3/4 inches, while the TDC lumbers in at 13 1/4 inches, which I think
qualifies the Compco as "much" smaller. (The older Compco "Triad" was a
beast comparable to the TDC in size, weight, and appearance, however! 
We used one at the Pasadena Stereo Club for a number of years.)  So I'll
concede that I overdid it a bit on the weight, if you'll give me "much"
on the size! {:>)   

-- 
Oliver Dean -- 3d-image@xxxxxxxxxxxxxx
Dominguez Hills (near Los Angeles), Calloushernia, USA


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