P3D Re: Themelis the Author

[Tom Hubin <thubin@xxxxxxxxx>]

Hello Dr T,

> My next project: "Stereo Projection".  I will use the very common
> TDC projectors as the basis to explain stereo projection.  

> Plus everything you need to
> know about setting the screen, adjusting the projector, screen,
> polarizing glasses, selecting light bulbs, etc.  And many
> details about the TDC projectors, including unique modifications
> like enlarging the apertures of the 716 for 7 sprocket slides,
> rewiring the 116 to have the fan on without the bulbs and more!

I may be able to give you some technical info. Aside from the article
(http://www.clark.net/pub/thubin/aosd/photo3d/ir_study.txt) that I
previously posted on modified TDC projectors and overheating slides, I
also reverse engineered the condenser lens prescription and spacing for
a TDC116 and a TDC716. 

I now have some practical experience with selection of repalcement
lamps. The filament size or dimensions are usually not considered in the
choice. The newer catalogs do not even give that info. Yet, that info is
essential if you want to get more light out of your projector. Wattage
and filament centering are not enough info.  

I also partially reverse engineered one of the projector lenses. I think
it was a 5 inch. Although I have a nominal index of refraction for each
lens of the air spaced Cooke Triplet, I do not know the 3 glass types. 

I have a pair of 4 inch projector lenses here but cannot get them open.
When I do figure out how to remove the retaining ring I will reverse
engineer that one too. I suspect that it is the same three lenses as the
5 inch but with a different spacing. Just a hunch, no basis in fact.

Tom Hubin
thubin@xxxxxxxxx
AO Systems Design


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