Variable viewer Illumination...needed or not?

[P3D Dr. George A. Themelis <fj834@xxxxxxxxxxxxxxxxxxxxx>]

I would like to present a few thoughts on variable viewer illumination.  
Is that a desirable feature in a slide viewer or not?

Statement #1:  Most *good* slides look better under bright illumination.

Explanation:  There are three kinds of 3D slides:  1) Good slides that 
look better under bright light like good scenics with brilliant colors, 
etc.  2) Good slides that look good under a wide range of illumination, 
like some mood slides, etc., and 3) Bad slides that actually look worse 
under bright light because you can see all their problems (lack of 
sharpness, etc.).  I have the so called "bright light test":  If a slide 
still looks good under bright light then it is a good slide (a"keeper").

Statement #2:  Variable illumination should *not* be used to compensate 
for incorrect exposure.

Explanation:  Sure you can do it, but it does not work.  By turning the 
illumination up in an underexposed slide you will see more details but 
you will also see grain, the blacks will be washed etc.  By turning the 
illumination down in an overexposed slide you still cannot see details 
in the overexposed areas, plus the color of the light turns muddy 
yellow.  In the words of immortal Dr. T: "There is a good place for such 
slides.  It's called the waste basket."

Statement #3:  Variable illumination could be used to compensate for the 
level of the ambient light.

Explanation:  What got me started in my quest for a brighter viewer was 
the following experience:  One day I brought a selection of my best 
slides to show to my boss at work.  The same slides that looked 
brilliant the previous night, now (under bright office illumination) 
looked dim, boring, unexciting.  My boss was not impressed.  The other 
night I had the opposite experience:  During the reception in the 
wedding, the lights were very dim and the viewer appeared blindly 
bright.  You could see every little spec of dust or grain in those 
slides.  Bright yes, but there is a limit.  So, what can we do?

To be continued in part II....


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