Edwin Land and the Retinax theory

[P3D Edward Gosfield III, MD <gosfield@xxxxxxxxxxxxxxxxx>]

Only marginally related to 3d, I suppose, but I witnessed a demonstration of
Land's Retinax theory of color perception in a wonderful lecture at Caltech
(around the late 1970s?)  A friend and I played hookey from work to attend,
and we had the additional pleasure of watching Land introduced by his buddy
Richard Feinman the physicist.

The demonstration was quite amazing, and included the use of  white light
projectors with two different color filters, which reconstituted a complete
range of colors. There was a considerable "OOOOhhhhh" and "AAAHHHH" effect
produced in the large hall of empirical minded engineering students and
faculty.   Land contended that the brain uses *changes* in intensity
(chroma) at the borders of objects to create/perceive the mental impression
of color.  He was also able to reconstitute a partial range of colors by
using one colored filter with a differently colored light source.

The Scientific American article "The Retinax Theory" was also very good .
Sorry i don't have the reference, but it was in the late 1970s, I believe.


I don't think this theory has yet been generally accepted as a true
physiological/neurological explanation of how the brain functions
biologically.  But i can say as an eyewitness that it certainly works as a
logical and functional explanation 'as if' our vision/brain works that way.
Perhaps Jim C. could discuss this further. 

And to remain on topic: how, if at all, does color perception influence our
perception of 3d?  (I'm too tired/lazy to check the archives first)  Is 3d
perception weaker during our dark-adapted vision (Purkinje shift to the blue
receptors)?

ted gosfield

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