P3D Re: Projection Alternatives

[fj834@xxxxxxxxxxxxxxxxxxxxx (Dr. George A. Themelis)]

Thanks for sharing your experiences with us.

I will now try and answer your projection questions based on my
(rather limitted) experience:

>1. For an audience of up to 15 people, would the TDC 116 projector (with
>500 watt lamps and 5" lenses) be sufficient? 

Yes, certainly!  This is what I have at home and this is what we use
at the Ohio Stereo Photographic Society club meetings.  One advantage
of the 116 TDC as compared to any stereo projector of the 50s is that
the carrier will show all formats, up to full frame.

>Or should I consider the
>TDC 716 with 750 watt lamps? Is investing in 4" lenses worth the extra
>money in either case?

I have not seen ANY significant difference in brightness using 750
bulbs (if there was a difference, it was in the order of .1-.2 fstops)
I personally prefer the 5" lenses for the club because then I can be
behind most of the people.  But I understand how some people with small
living spaces prefer the 4" lenses.  At home I can fill a 70" screen
with the 5" lenses so I am happy with my 5" lenses.  Considering the
demand for the 4" lenses, I guess others are not very happy.

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

Superior to the TDC from the 50s? I don't think so.  Charles Piper says
that the Realist 82 with 1000W bulbs and f2.3 lenses is better for 
public showings but I have no experience with this.  Comparable is the
Compco Triad projector.  Contemporary stereo projectors include the FED
(have never seen/used one), the Brackett Dissover which is not made
at the present time, and the RBT which is great if you have the $$$$.

>3. What are the best sources for these projectors?

Stereo dealers (Dalia, Mr. Poster), stereo enthusiasts (DrT etc.) posting
in sell-3d, camera shows, camera stores, Shutterbug classifiers, Stereo
World classifiers, ebay auctions.... These are just a few sources.
The BEST source is definitely the garage sale that has a TDC priced
at $15 (YES, it happens!!! - NOT TO ME THOUGH!)

>4. Can I continue to use my carboard heat-seal mounts in a projector or
>do I need to use another material, such as glass, to prevent heat damage
>to the film?

I say YES, you can keep on using your cardboard heat seal mounts.  Others
will try and convice you to mount in glass or RBT mounts, not for the sake
of your film but for the sake of your audience.  Mounting errors are
amplified in projection.  If you do a good job with the cardboard mounts
you will not have a problem.  If you do have a problem then you don't
do a good job and you cannot see it or it does not bother you in the
viewer.

>5. Can the TDC projectors handle 35mm pairs? I may someday try using
>twinned cameras or the "cha cha" method and would hate to be forced to
>purchase a new projector.

You don't have to buy any new hardware to view/project full frame stereo
slides, if they are mounted in RBT or Spicer Wide mounts.  This is the
point I am trying to explain in a newsletter article I am writing right
now.  I personally convert Realist red button viewers to view full 
frame slides mounted in standard 101x41 mm frames.  The Kodaslide can be
modified too but only up to 7p.  The TDC 116 will show full frame slides
in wide mounts without any modification.  I use and mix all different 
sizes in projection shows and in my viewer.

>6. From recent comments on photo-3D digest, I understand the Da-Lite
>WONDER-LITE and Da-Lite SUPER-WONDER-LITE seemed the best amd brightest
>screens. Is this the general consensus of the group? And which size
>would you recommend for my purposes?

I have a DaLite screen and it works well.
50" is the standard recommended size.  40" is a bit too small.  If you
feel particularly brave and have the space, go with the largest size
(70", that's what I use).

>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. 

Two more important points:

- Reliability/maintenance:  The TDC and other 50's projectors are very
simple and among the most reliable.  I think even Mike Watters will not
dispute this! :-)

- Convenience:  The TDC weighs some 30 lbs.  Not very convenient to carry
around, but, what the heck!  How often will you take it in the plane to
Europe with you?

- Introducing people to stereo via stereo projection:  Some people have
mentioned that this is not the best way to do it, due to distortions
(stretch) from the fact that most people sit well behind the ortho seat.
I partially agree with these concerns.  Some pictures, especially Realist
shots of people at close range (7 feet) will look very distorted for the
novice.  Perhaps the viewer is the best way to start.  Projection follows.
Also, many people comment that some slides that look great in the viewer
do not look very good in projection.  This happens often.  The reverse
is rather rare but happens too.  You will learn to have favorite projection
and favorite viewer images.

Regards, and I hope you are subscribed to sell-3d because I am ready to
post a few stereo projectors for sale within the next few weeks!!!

-- George Themelis


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