MIxed and reflected color frequencies.

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Discussion Overview

The discussion revolves around the nature of color perception when mixing different light frequencies, specifically yellow and blue light, and how this relates to the structure of the reflected light. Participants explore concepts of additive and subtractive color mixing, the physiological effects of color perception, and the differences between light and pigment mixing.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • Some participants propose that the reflected light from a mixture of yellow and blue photons results in the perception of green, questioning whether this is due to the presence of a green photon or the simultaneous detection of both yellow and blue photons by the eye.
  • Others argue that the sensation of green is a physiological effect caused by the excitation of retinal receptors, and that the reflection process does not alter the frequency of the incoming photons.
  • A participant mentions that mixing paints results in different outcomes than mixing light, noting that paint mixing leads to subtractive color mixing, while light mixing is additive.
  • There is a discussion about the implications of metamerism, where different combinations of light can produce the same color perception, suggesting that color perception is complex and dependent on various factors.
  • Some participants highlight that the mixing of blue and yellow paints leads to the absorption of certain wavelengths, while a mixture of blue and yellow light does not eliminate photons but rather combines their effects.
  • Concerns are raised about the limitations of human color perception, particularly regarding the inability to distinguish between pure colors and combinations of colors without additional context.

Areas of Agreement / Disagreement

Participants express multiple competing views regarding the nature of color perception and the mechanisms behind it. There is no consensus on whether the perception of green arises from a distinct green photon or from the combination of yellow and blue photons.

Contextual Notes

Participants note that the discussion involves complex interactions between light and color perception, including the roles of different pigments and the physiological responses of the human eye. Limitations in understanding the exact nature of perceived colors and the effects of mixing different light frequencies are acknowledged.

Edi
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When I shine two different lights at a single spot on a white screen, say, yellow and blue, they both hit the spot and get reflected all mixed up and I see green. Thats all fine, but what is the actual structure of that reflected, in this case, green light? Is it a ordinary green photon with its corresponding frequency? (say, 510nm )or is it the same blue and yellow photons, but our eyes just detect both at the same time, from the same spot, and interpret it as green?
 
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Hi.

Edi said:
When I shine two different lights at a single spot on a white screen, say, yellow and blue, they both hit the spot and get reflected all mixed up and I see green. Thats all fine,

We would not perceive green light in combination of blue and yellow light though I do not know what color we perceive of it.

Instead, three fundamental color of paint are Cyan, Magenta and Yellow. Cyan absorbs Red light. Yellow absorbs Blue light. So mixed paint of Cyan and Yellow absorbs Red and Blue lights, thus Green light, which consists three fundamental light color with Blue and Red, mainly remains in the reflected light. It consists actually of green photon. Regards
 
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Edi said:
When I shine two different lights at a single spot on a white screen, say, yellow and blue, they both hit the spot and get reflected all mixed up and I see green. Thats all fine, but what is the actual structure of that reflected, in this case, green light? Is it a ordinary green photon with its corresponding frequency? (say, 510nm )or is it the same blue and yellow photons, but our eyes just detect both at the same time, from the same spot, and interpret it as green?

The light reflected from the white screen contains the yellow and blue photons.
The normal reflection does not change the frequency of the photons.
The sensation of green is a physiologic effect due to simultaneous excitation of the receptors in the retina. The reflection is irrelevant actually. If you send the two beams directly to the eye you'll see green too.

The mechanism of the color vision was disused extensively in a thread some time ago.
 
So, with nothing but my natural sensors (eyes), I cannot know if I am looking at a green color (or any other color) or a combination of two or several..
 
if we paint rainbow's color on a circle top and rotate it,wecan see color white. that means our eyes have a time limit to distinguish different colors.
 
Edi said:
So, with nothing but my natural sensors (eyes), I cannot know if I am looking at a green color (or any other color) or a combination of two or several..
Yes, this effect is called http://en.wikipedia.org/wiki/Metamerism_(color)"
 
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Hi.

nasu said:
The light reflected from the white screen contains the yellow and blue photons. The normal reflection does not change the frequency of the photons.
The sensation of green is a physiologic effect due to simultaneous excitation of the receptors in the retina. The reflection is irrelevant actually. If you send the two beams directly to the eye you'll see green too.

Is it true we see green color when blue photons and yellow photons are coming together into eye ?
As for paint mix of blue paint and yellow paint cause deletion of two complimentary colors and only almost green color can be reflected.
how about addition of blue photon and yellow photon?

Mix of various paint is black, however, mix of various photon is white.

Regards.
 
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sweet springs said:
Hi.



Is it true we see green color when blue photons and yellow photons are coming together into eye ?
As for paint mix of blue paint and yellow paint cause deletion of two complimentary colors and only almost green color can be reflected.
how about addition of blue photon and yellow photon?

Mix of various paint is black, however, mix of various photon is white.

Regards.
Blue paint reflects more blue photons and yellow paint reflects more yellow photons. A mixture of blue and yellow paint will reflect both blue and yellow light (unless there is some interaction between the pigments which will change their nature). For solid pigments (like oxides) you can still see individual grains (and their individual color) with a microscope whereas the overall sensation is that of the "mixture color". The yellow pigment does not "eliminate" the blue photons reflected by the blue pigment.

You can think it in terms of "eliminating the complementary color" but this is just an useful tool. The result is the same but the physics is not.

There is no "addition" of photons. Mixing beams of photons with various frequencies does not change the nature of the photons (in the usual conditions discussed here).

And yes, seeing some colors (physiologic response) can be due to excitation of retina by more than one combination of photons.
 
Delta Kilo said:
Yes, this effect is called http://en.wikipedia.org/wiki/Metamerism_(color)"

This is actually a good thing. It means our color printers do not need ink cartridges with 10 million different colored inks inside. Just three will do.
 
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  • #10
sweet springs said:
As for paint mix of blue paint and yellow paint cause deletion of two complimentary colors and only almost green color can be reflected.
how about addition of blue photon and yellow photon?
Mix of various paint is black, however, mix of various photon is white.

PS
See figures on additive and subtractive color mixing in Wiki Primary color. http://en.wikipedia.org/wiki/Primary color
 
Last edited by a moderator:

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