Posted by Bill Farnsworth on 07/03/06 15:14

"Richard Crowley" <rcrowley@xpr7t.net> wrote
> Alas no amount of white-balance or painting the R/G/B
> gains/pedestals will produce a "color" picture under a
> source as monochromatic as sodium vapor. Not with
> electronic video, nor with chemical film.
>
> We have a similar situation in the cleanroom fabs where
> we manufacture microprocessor wafers (perhaps the one
> in the computer you are reading this on!) . Part of the fab is
> illuminated with orange light that looks for all the world
> like those "bug lights" people use for porch lights to
> avoid attracting insects. The photo-sensitive "resist"
> that we use to expose the patterns on the wafers is not
> sensitive to this partiuclar wavelength, so it is very much
> like a photography darkroom "safelight".
> But the light is so unbalanced that it is nearly imposible
> to properly white-balance under. One of our cameras
> will almost do it, but we discovered that people who
> are looking at the video become disoriented when they
> see the "litho area" looking as if it were illuminated in
> white light. So our SOP is to white-balance in the white
> illiminated area, and then to just shoot in the yellow
> litho areas as-is and let the video go yellow.

Yeah. That's pretty much the answer, Richard. It is what it is. And in
my opinion, The color of Paul's footage is quite pleasing.
Again, it is what it is and at night, that is what we see anyway.
If you ain't got the budget to change all the globes in the shot to
tungsten or metal halide then there isn't anything that can be done to
correct the shading where one would ideally like it.
In some areas streetlights on minor roads, parking lots and pedestrian
walkways are now being converted over to full spectrum 3200 LEDs.

Bill F.
www.billfarnsworthvideo.com

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