P3D Re: Projection Alternatives

[Bill Davis <bd3d@xxxxxxxxxxxxx>]

Len Lavenda asks:

>1. For an audience of up to 15 people, would the TDC 116 projector (with
>500 watt lamps and 5" lenses) be sufficient? Or should I consider the
>TDC 716 with 750 watt lamps? Is investing in 4" lenses worth the extra
>money in either case?

How far back from your anticipated screen position can you place the
projector?  The 5" lenses need a lot of room to fill a big screen. 

>From TDC Stereo Vivid "Operating & Maintenance Instructions" by Earl Krause
and Robert McIntyre:

projection distance table (in feet)
American standard stereo, 22 x 23 mm aperture

width of screen (inches)        40        50        60        70        84

4" lens                         16       19.5       23        26.5      31
5" lens                        19.5      24.5       28        33        39 



Doc T apparently lives in a bowling alley.  :--)  I had to take a wall out
between rooms to get the required distance to fill a 50" scereen.

>2. Are there any other projectors that might be comparable or superior
>to the TDC models? 

Dr T mentioned the Realist 82.  It sure looks cool, and the specs are top
notch, but prices tend to be in the $1000 range. 

According to some owners, the Compco Triad has better features than the
TDC, with adjustments being more conveniently located, as I recall. Pricing
is about the same. 

The TDC gives you a lot of bang for your buck. You can show 2x2 (singles)
if you have the correct slide carrier (there were at least two different
designs, I understand). Whether you could project pairs of 2x2 in the TDC
is a good question.  The problem would be how to maintain the spacing
between slides.  Since the carrier feeds the dlides in from one side, each
slide pushing out the previous one, you would need to create some sort of
spacers to use between each pair.  I think you might also have to modify
the carrier to allow the other lens to be used for 2x2.  Never looked into
it, so I'm not sure.    

The TDC can even project View-Master(tm) reels, using a simple adapter you
can make in an afternoon from a View-Master(tm) viewer.  Gabriel Jacob has
also made an adapter using one of the View-Master(tm) 2D projectors.  

>
>I don't know if I neglected any important considerations (e.g.,
>reliabililty, convenience, maintenance, etc.), but if so, I'd very much
>appreciate any additional thoughts or tips. 

A drawback to the long lenses (for me) is that from the projectionist's
position, razor-sharp focus was difficult to obtain.  Yelling back and
forth to the front of the room (the fan is *loud*) and twiddling the focus
knob eventually gets you a sharp image, but this frustrated me to the point
that I cobbled up a remote motorized focus for my TDC. Now someone up front
focuses. Ugly would be an understatement, but once the lights go down
everyone is looking at the razor-sharp images, not the mutant projector.

>
>Regards,
>Len Lavenda


Best regards,
Bill Davis
mailto:bd3d@xxxxxxxxxxxxx



------------------------------