P3D Re: Which Is The Best All-Around Stereo Viewer??

[Tom Hubin <thubin@xxxxxxxxx>]

Al Knecht wrote:
> 
> To Doctor George, regarding my query on magnification, I want to thank you
> for your  very informative input.
> 
> My new question to any and all enthusiats is regarding "Which Is The Best
> All-Around Stereo Viewer and Why??"  I recently sold my White-button Realist
> viewer for a premium and replaced it with a Red-button. But I did not notice
> much increase in clarity or less distortion when contrasted against the
> single element "white button".  Do you believe that the Red-button is still
> better in all respects to a Kodaslide II  ?  On a side note,  I bought a
> Revere22 and was not impressed with the optics at all. On most of my tests
> using an original GE bulb verses a newer halogen bulb, I sometimes feel that
> the standard bulb is brighter. I guess I am asking for a viewer that is the
> "best" in all aspects. Those aspects include, optics, brightness,
> distortion-free, large image, finger-free lighting, etc.
> 
> Thanks,
> 
> Al

Hello Al,

Regarding brightness. If the halogen bulb has a larger filament than the
original bulb you may be losing light. I am not familiar with the
viewer. However, a projector's condenser optics usually image the bulb
filament at the projection lens entrance pupil. And just large enough to
fill the pupil. 

If you substitute a bulb with a larger filament then its image at the
projection lens may be overfilling the entrance pupil. If that is the
case, you will lose light.

Last year I did a study on TDC116s modified to use a 750w halogen lamp
instead of the original 500w lamp. The 750w lamp burned up some slides
due to 50% more infrared energy at the slide while providing a dimmer
screen image bercause the filament is too large for the condenser
design. 

For more detail on lamp substitution, light losses, and heat problems
with TDC modifications see 
http://www.clark.net/pub/thubin/aosd/photo3d/ir_study.txt .

Tom Hubin
thubin@xxxxxxxxx
AO Systems Design