P3D Re: No more two-color nonsense

["William J. Carter, Ph.D." <wc@xxxxxxxxxxxx>]

At 06:35 AM 8/20/98 -0600, Tom Deering wrote:

>... On the other hand, the product of two
>colors is always missing a huge part of the spectrum that a child can see
>from a distance.

If anyone is still confused by this issue, the problem can be seen in the
sentence quoted above, where Tom says, "the product of two colors..". The
dynamic of the anaglyph is not the addition, "the product" of colors, but
the subtraction of colors. 

Think of a "sky light" filter; it is a single broad band filter which passes
most, if not all of the visible spectrum. There, full color with only one
filter. 

Now, if you were to divide the spectrum in half, so you could keep separate
the left and right channels of a stereo pair, you would end up with two
"color" filters, which when recombined, would give you back the original
full color.

And yes, filters aren't perfect, which is why in critical applications
dichroics are generally used.


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