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Color wheels are wrong? How color vision actually works

blog.asmartbear.com

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Re: Color wheels are wrong? How color vision actually works

#11

Post by NonMint »

lukev wrote: post #7

I wish I could upvote this twice. I hadn't realized that our actual perception of color was so filtered from the physical spectrum. I find it incredibly fascinating, from a philosophical perspective, that there are literally color combinations (i.e, greenish-red) that, despite lying within the physical spectrum to which our eyes are sensitive, we cannot see , cannot even imagine.

The thing that will really blow your mind is are there things that are red, or a group of things that have a common appearance that our minds just label "red." And what if what if the signals that reach my brain when I view "red" are shifted one to the left on the color wheel? The gradual perception of color change would be perceived but we would be looking at different colors even though we both agree that it is "Red."

Re: Color wheels are wrong? How color vision actually works

#12

Post by sfphotoarts »

michael_dorfman wrote: post #5
sfphotoarts wrote: post #3

while the article looks like a mashup of text-books and wikipedia (not to mention the self-aggrandization) and is interesting, this looks like SEO spam, one of these sites that sells you some book on how to get rich quick or how to start your startup. I think I'll stick with my Johannes Itten.

You talk about what the article "looks like", but have you actually read it? I found it to be a well-written, well-researched introduction to some of the problems in color theory. If that's what you mean by "a mashup", then I guess all secondary literature is. As for the site, asmartbear is no stranger to these parts, and Jason's posts are well-regarded.

possibly my British grammar is stumping you, but yes, to read something you have to look at it.

This article might appear well researched here, but this is the hello-world equivalent on an art forum.

Maybe if Jason believes he has something meaningful to contribute to color theory, he should consider updating the Wikipedia page rather than promoting his own self interest by advertising his book & blog on HN.

Re: Color wheels are wrong? How color vision actually works

#13

Post by jessriedel »

EDIT: joeld42 answered my question elsewhere on this page:

http://news.ycombinator.com/item?id=2166782

The artists reds and blues are just approximations to the magenta and cyan of printers.

----

So I understand that in order to mimic the electromagnetic stimulation to the cones you only need to control the amount of RGB light hitting the retina. And I understand that propagating light is additive, so that for light producing displays you mix amounts of RGB, whereas pigments subtract light, so that for printing you mix amounts of CMY. (C paint absorbs non-R light, M paint absorbs non-G light, and Y paint absorbs non-B light.)

I further (kind of) understand that once printing and CRT screens are explained, there are additional properties of light due to the filters described in the article.

But can someone explain why the artist's paints are different from the CMY ink pigments? It seems like it's either (a) something weird about the way paints mix, (b) artists use paints which somehow take advantage of the filters in the eye, or (c) a combination.

Re: Color wheels are wrong? How color vision actually works

#14

Post by bobds »

Site was temporarily unavailable when I tried to post a comment, so here it goes:

This post clears up a few misconceptions for me, thanks for that.

I think you will enjoy the following link about "context" related illusions: http://www.psy.ritsumei.ac.jp/~akitaoka/color12e.html

Akiyoshi Kitaoka is a university professor from Japan that has created a very extensive and amazing collection of illusions, documenting so many subtle ways our eyes play tricks on us.

His homepage is really worth exploring:

http://www.psy.ritsumei.ac.jp/~akitaoka/index-e.html

Re: Color wheels are wrong? How color vision actually works

#15

Post by sfphotoarts »

joeld42 wrote: post #9

This article tries to sensationalize and obfuscate something that is pretty simple in reality. RGB are the primaries in light. By mixing these three colors you can create any color the human vision system can perceive (yes, because of tristimulus). When white light hits a material, some of those RGB wavelengths are absorbed (subtracted). RGB - GB(Cyan) = Red, RGB - RG(Yellow) = Blue, RGB - RB(Magenta) = Green. Thus,…

You said it with more finesse, but exactly. This is just an badly written article on a subject that is clearly not understood by the author trying to grab eyeballs through sensationalism.

Using printer inks as an example was the first big cue that this was link bait to a self-aggrandizing blog.

Re: Color wheels are wrong? How color vision actually works

#16

Post by bobds »

joeld42 wrote: post #9

This article tries to sensationalize and obfuscate something that is pretty simple in reality. RGB are the primaries in light. By mixing these three colors you can create any color the human vision system can perceive (yes, because of tristimulus). When white light hits a material, some of those RGB wavelengths are absorbed (subtracted). RGB - GB(Cyan) = Red, RGB - RG(Yellow) = Blue, RGB - RB(Magenta) = Green. Thus,…

> just basic stuff presented as if it were obscure or clever.

I think the part about the three filters is at least somewhat obscure and probably the most useful thing I learned from the article.

Re: Color wheels are wrong? How color vision actually works

#17

Post by foljs »

NonMint wrote: post #11
lukev wrote: post #7

I wish I could upvote this twice. I hadn't realized that our actual perception of color was so filtered from the physical spectrum. I find it incredibly fascinating, from a philosophical perspective, that there are literally color combinations (i.e, greenish-red) that, despite lying within the physical spectrum to which our eyes are sensitive, we cannot see , cannot even imagine.

The thing that will really blow your mind is are there things that are red, or a group of things that have a common appearance that our minds just label "red." And what if what if the signals that reach my brain when I view "red" are shifted one to the left on the color wheel? The gradual perception of color change would be perceived but we would be looking at different colors even though we both agree that it is "Re…

Yes, it would blow my mind, if that wasn't the kind of stuff 12 years old sci-fi fans talk about, you know, the kind confusing semantics games with reality...

Re: Color wheels are wrong? How color vision actually works

#18

Post by lutorm »

jessriedel wrote: post #13

EDIT: joeld42 answered my question elsewhere on this page: http://news.ycombinator.com/item?id=2166782 The artists reds and blues are just approximations to the magenta and cyan of printers. ---- So I understand that in order to mimic the electromagnetic stimulation to the cones you only need to control the amount of RGB light hitting the retina. And I understand that propagating light is additive, so that for light…

Maybe you mistyped, but cyan paint absorbs red light, it reflects everything but red, i.e. cyan.

Re: Color wheels are wrong? How color vision actually works

#20

Post by Zaak »

kylec wrote: post #10

I must have missed something as a seven-year-old, because this is the first I've heard that blue and yellow were supposed to be opposites. To me, it always made sense that blue and orange were opposites, both conceptually and visually. The same with purple and yellow.

It's possible you're an anomalous trichromat: http://en.wikipedia.org/wiki/Color_blindness#Anomalous_trich...
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