Re: Viewer lighting

["The Photo-3D List" <photo-3d@xxxxxxxxxxxxxxx>]

>    The frosted bulb helps even out the light but there is still
> a bright spot on the diffuser where the light comes straight from
> the bulb to your eye. I am considering placing a small (bulb sized)
> diffuser between the bulb and the main diffuser to even out the
> light.

I have a general idea off-the-cuff that might help with light uniformity
at the cost of less brightness.

Seems like one could photograph the light source as seen by the 
viewing lenses.  In B&W with perhaps some neutral density filters. Take
them using a large format camera such that there's a 1:1 relationship
between the difussion glass and the film.  With suitable processing, the
negative would be a "perfect" brightness correction filter assuming the
brightpoint-to-darkpoint on the diffusion glass has a smaller range than
the film's dynamic range.  The film would then be inserted before or after
the diffuser, or perhaps with a secondary diffuser (for heat shielding).
Processing the film for proper density may take a few tries, but maybe
some Zone technique application may get the first try somewhere close.

Seems like near-perfect uniformity would be possible with a bit of fussing.

Would be dimmer though.  The uniformity would be achieved by dimming the 
brighter spots down to the most dim point.

No, I haven't tried this.  Seems like it might work though.

Mike K.


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End of PHOTO-3D Digest 1249
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