
The eyes have it: Seeing ultraviolet, exploring color - evo_9
http://www.extremetech.com/computing/118557-the-eyes-have-it-seeing-ultraviolet-exploring-color
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jacobolus
The original source about seeing ultraviolet is interesting:
[http://www.komar.org/faq/colorado-cataract-surgery-
crystalen...](http://www.komar.org/faq/colorado-cataract-surgery-
crystalens/ultra-violet-color-glow/)

Worth noting is that the eye filters shorter wavelengths partly to protect the
cone cells. Most animals (like various insects) that see further into the
ultraviolet have much shorter lifespans than humans, and so damage doesn’t
have as much impact.

The rest of the article is just somewhat muddled rehashes of Wikipedia
articles (which makes me realize once again that some of these color vision
articles need dramatic improvement to avoid confusing people). For instance,
this guy’s changed ultraviolet sensitivity doesn’t give us any insight into
how tetrachromats see; he is still a trichromat, just with a slightly
different short-cone-cell wavelength response.

To understand color vision, I’d recommend Bruce MacEvoy’s site,
<http://www.handprint.com/LS/CVS/color.html>

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count
So, this is a question I've not been able to find an answer for that's
relevant:

Where are the non-visible light sensitive CCD-style cameras?

Why can't I take a 'picture' of the 2.4Ghz bouncing around my condo? Or the
1900Mhz rolling through walls and buildings? Things that are 'rf blocking'
should show up brightly, while things that are 'rf transparent' should be
...well, transparent, like glass.

I feel like I'm misunderstanding a fundamental difference between 'light' and
'rf' here, so please point it out if I am.

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wtallis
Those frequencies you are asking about correspond to wavelengths of several
inches. That would require a very large and thick camera, and probably a
different sensor technology to be sensitive to the less energetic photons.
Near-infrared and UV are easy, though.

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count
TIL that visible light is in the 400-800THz range. Things make way more sense
now, I never realized it was that crazy high, relatively. Now I'm on a quest
to build a RF pixel camera - thanks for the idea!

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jakeonthemove
Interesting read, but I don't see why I'd care about my "blunderbuss" TN panel
- it's good enough for work. Also, I think the color gamut picture is flawed -
since I have a TN panel, I can't possibly see the IPS gamut, and yet there is
a clear difference - how is that possible?

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wtallis
If color correction isn't being done on the image, then the image you see has
essentially had its color space compressed. When displayed on a wide-gamut
display, the "TN" part of the image will match how the "wide-gamut IPS" part
looks on your TN panel. (Ignoring dithering and the color inaccuracy of the TN
panel.)

If the image was being properly color-corrected, then all the parts of it
would look pretty much the same, since all but one of them has the signal
clipped when it gets displayed by your monitor, due to the colors being out of
range. (This is, of course, assuming that your TN panel has roughly the gamut
and color response curve that are being emulated by the image, and that your
TN panel has been calibrated to display colors accurately within the
achievable gamut.)

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alanfalcon
"As an example, try visualizing a color made from red and green (not the
mixture of the two pigments, which would be brown, but a hypothetical color
'reen' made from elements of each)."

Um, yellow is the combination of red and green. Am I missing something?

EDIT: I just feel the author does a poor job of wording his thought
experiment. When I visualize a mixture of red and green I visualize either
brown or yellow, and since he said he didn't mean brown that leaves yellow.

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windsurfer
There are different ways to mix color:

<http://en.wikipedia.org/wiki/Subtractive_color>

<http://en.wikipedia.org/wiki/Additive_color>

Light is additive, so that's yellow. He's talking about pigments and paints,
which are subtractive.

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evincarofautumn
According to what research I’ve read, tetrachromacy has been demonstrated in a
handful of females with a family history of colourblindness. However, there’s
nothing precluding an XXY male from being a tetrachromat. Indeed, 1 in 1000
males are XXY and most are asymptomatic, and I have good colour
discrimination, so I’ve always wondered if I might be a tetrachromat. Too bad
there’s no way to test it on your standard-issue RGB LCD…

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dhughes
It would be cool if he could see X-rays in the 10 nm range from what I have
read UV and X-rays seem to overlap in that area at 10 nm. But the link to his
page shows he can see 340 to 350 nm at best.

