This is what makes me question the colour blind theory. Although they are very strong in places, the colours all work together.
If he was colour blind surely there would be patches of green and patches of non-green instead of smooth colour. How could he possibly match the same colours over and over again each time he mixed his paints if he couldn't tell the difference?
I'm not an expert in oil painting technique, but I think one possibility is, you tend to overpaint an area at a time. So: mix some paint, layer up part of the canvas. Come back later, mix some paint, do it again.
If that's how it works it would explain a bunch of things in the comparison images. Like: how come the bridge is yellow, but its reflection in the river is bright green? Maybe they were painted at different times.
The colors don't necessarily look identical to him. If you have trouble see in green, and two colors differ by how much green is in them, you might perceive the two colors to be closer together than someone with normal color vision perceives the two colors.
I think that's what you see in a lot of the pictures. Look at the green in the coat in the self-portrait. What appears as distinct lines of green in the normal color version becomes muted in the modified color version and blends in much more with the other colors, but with just enough difference to lend a rich texture to the coat.
Why would you separately put two "different" colors of paint on your pad, when as far as you can tell they are identical?
I can understand mixing them, or using first one then the other (after you run out of one) - but shading the image partly with one color and parts with another?
The only conclusion is that they were not identical to him, and this software is not correctly showing us what he saw.
Simple: You mix the colors one way, paint for a while, go off to some other part, mix the first color again, and paint again. If you can't tell the differences between two colors, it's easy to come up with two similar/'identical' colors that are really quite different to someone with a different color perception.
While this article doesn't remotely prove that this is what's happened, it seems like a possibility to me.
The effect where colors with different spectral power distributions matches under certain conditions due to the observer or the light source, is called metamerism.
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In some of the converted pictures two colors that were different in the original become identical.
If Van Gogh saw colors the way they are in the converted pictures why would he use two different colors that would look identical to him?
Oil paintings aren't painted in a single go. There's a lot of layering involved.
So perhaps a better question is, how would you mix the same color twice, if you couldn't tell a range of colors apart?
This is what makes me question the colour blind theory. Although they are very strong in places, the colours all work together.
If he was colour blind surely there would be patches of green and patches of non-green instead of smooth colour. How could he possibly match the same colours over and over again each time he mixed his paints if he couldn't tell the difference?
I thought about this for a while.
I'm not an expert in oil painting technique, but I think one possibility is, you tend to overpaint an area at a time. So: mix some paint, layer up part of the canvas. Come back later, mix some paint, do it again.
If that's how it works it would explain a bunch of things in the comparison images. Like: how come the bridge is yellow, but its reflection in the river is bright green? Maybe they were painted at different times.
The colors don't necessarily look identical to him. If you have trouble see in green, and two colors differ by how much green is in them, you might perceive the two colors to be closer together than someone with normal color vision perceives the two colors.
I think that's what you see in a lot of the pictures. Look at the green in the coat in the self-portrait. What appears as distinct lines of green in the normal color version becomes muted in the modified color version and blends in much more with the other colors, but with just enough difference to lend a rich texture to the coat.
I'd blame that on the author's image processing.
It's also several times more common to be green-deficient than it is to be missing that cone entirely.
Let me ask this in another way, why would you not use two different colors as one, if they look identical to you?
Why would you separately put two "different" colors of paint on your pad, when as far as you can tell they are identical?
I can understand mixing them, or using first one then the other (after you run out of one) - but shading the image partly with one color and parts with another?
The only conclusion is that they were not identical to him, and this software is not correctly showing us what he saw.
Simple: You mix the colors one way, paint for a while, go off to some other part, mix the first color again, and paint again. If you can't tell the differences between two colors, it's easy to come up with two similar/'identical' colors that are really quite different to someone with a different color perception.
While this article doesn't remotely prove that this is what's happened, it seems like a possibility to me.
The effect where colors with different spectral power distributions matches under certain conditions due to the observer or the light source, is called metamerism.
http://en.wikipedia.org/wiki/Metamerism_%28color%29