

The myth of RGB: To represent all colors you'd need negative red - nickb
http://www.mathpages.com/home/kmath578/kmath578.htm

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lutorm
The title is a little misleading, isn't it? You can _represent_ the colors
without negative colors, that's what you do with the XYZ basis they talk
about. What the article claims is that you can't _replicate_ all possible
color stimuli in the physical world with three monochromatic bases.

I finally understood why high-quality ink jets have so many inks. They split
the visible color space up into a higher order polygon than the basic RGB
triangle.

~~~
marvin
...and the happy news is that this stuff is within the possibilities of
current technology: make a computer-controlled array of LEDs, each LED
producing a narrow frequency band. Given sufficiently powerful and narrow-
banded LEDs, this kind of light source could simulate any spectrum.

Natural medicine freaks often complain that artificial lightning doesn't
produce the same sensory response (and thus psychological well-being) as
sunlight. Our fictional light-source could simulate any light condition, and
even change during the day. We would be able to prove them right or wrong.

I've been bitching about this for quite some time, because I really want
something like this. I'm glad others are thinking the same thought.

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jacobolus
> _Given sufficiently powerful and narrow-banded LEDs, this kind of light
> source could simulate any spectrum._

As far as I know, this is currently extremely unrealistic, if you're looking
for something like a display. If you just want a light bulb type source, you
could maybe do a rough approximation, very expensively.

> _complain that artificial lightning doesn't produce the same sensory
> response (and thus psychological well-being) as sunlight._

It empirically does not produce the same sensory response. Psychological well-
being is a bit harder to measure.

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nazgulnarsil
_This helps to account for our optical “absolute pitch”, because the three
types of cones are effectively “tuned” to respond to certain absolute
frequencies._

no it doesn't, because inside our ear there are stereocilia "tuned" to each
specific frequency one can hear. Yet we can not generally discern absolute
pitch.

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lutorm
True, but it makes sense that it's easier to discern the 3 different rod
responses absolutely than the 3000 (according to the article) different
response functions of the ear.

~~~
nazgulnarsil
we can discern millions of colors though.

