Hey Taran,... sooo multiple things: You got the part at 13:45 wrong, and well, the image you show is also wrong, but here is how it works: The three curves labelled L, M and S at 14:00 are the actual cone sensitivities, as you correctly stated. The image at 13:45 shows the so called colour matching functions (CMF). They are the result of multiple studies and are created in the following way: You have three monochromatic light sources shining at one eye, and a single monochromatic light for the other eye. The single light is stepped through all wavelengths. The human test subject is now tasked to adjust the three monochromatic lights so, that they match the single one. Out of that you get the intensities of the three wavelengths you set as primary colors that you need to combine to get any single one wavelength color. I had to work through this for my master thesis in photonics and my god, its easy to mess up along the way. If you need a good source for all the base data and honestly one of the best explanations for all the scientific background go to "The Colour & Vision Research laboratory and database" cvrl. It goes all the way to the scientific base of how these functions are made and where they come from. While cvrl goes into the human aspect of the colorimetry, a site that covers basically all the computational part of it is "bruce lindbloom" (hard to convey the site name when its literally just his name,... just google the name and you should find it). Finally as for the image of a prism you can find one if you search on Wikimedia commons with the query "Színszóródás prizmán2", its sadly not in the PD and feels off, but it shows the purple you're searching for. In any case, love your videos about color and graphics.
Let's try this again, and hope UA-cam doesnt take this as spam: The thing you talk about at 16:05 can be explained by the CMFs from my main comment. While yes, there are pure wavelengths that look violet, all of our colour science is built on the three primaries, and to make violet we use the combination of the red and blue. Because of this you can remove the red part of the violet. The reason there are so little photos of prisms that show actual violet could be because of multiple reason. First, they could have used a lightsource to make the photo, that is not hot enough to produce meaningful amounts of violet/UV radiation. The second reason is the glass the prism is made out of. Most standard types of glass basically don't transmit UV-radiation and can have a hard time with violet already. If you want some examples for transmittance curves of glass prisms you can look at the "ThorLabs" shop with the search query "Equilateral Dispersive Prisms". A way to get around that limitation of the transmittance is the use of an optical grating, since it doesn't necessarily transmits through a glass medium. I cant post the link to the image here but you should be able to find it by searching on "fineartamerica" for "light dispersed by diffraction grating". Now this is obviously not in the public domain, but it should be a good image to use as a reference for how these things can look.
Please make more informational videos like these 🥺, this type of video is just elite level UA-cam content. This alongside your colour correction series and the upscaling video are tremendously helpful and informative. Thank you sir 🙏
Saw this on Nebula. At 17:00 Taran asks what if humans had 4 cones in the eye. Some people do. Human tetrachromacy is rare, but it does occur in two ways. Naturally occurring tetrachromacy happens only in women. Near-UV tetrachromacy can occur after lens replacement surgery. There's an article on Extremetech about this.
Awww, thanks! We love to bicker like that. After about 3 years together, we still have not had any real fights. We are always randomly hugging and kissing each other during the day. I've never loved someone so much.
I love that pedantic videos about color representations are becoming common enough to be A type of video I enjoy. Technology Connections video about brown is A classic!
There sort of are tunable lasers, a supercontinum laser with an optoacoustic filter is how ive seen les of "Les' lab" here on youtube do it, hugens optics also has some similar cool optics shenanigans, love the videos, looking forwards to more and hearing how things have been post LMG
Love watching these with my colourblindness, flipping on a filter every now and then. (I've never truly seen purple, looks like a dark blue most of the time.) At 7:33 with no filter, I don't see any hint of red beyond 1/3, 1/2 and 1/4 of those bars. With a filter, it looks like there might be a red component to 1/2, 2/3 and 1/3 of them, with the last bar doing *something* in the middle.
I love kinds of videos on topics where you could probably keep digging and digging and still there'll be something you missed or don't understand. Nature really is weird.
Focusing on the blus and red diagrams has really fucken my colour perception, both my eyes are now seeing different things one is warm the other is cold but the world as whole is bluer
My favorite color :y (Specifically the way the colors mix in the middle bar is closest to my favorite but they’re all bangers. I think most people call that middle one fuchsia. Maybe that’s just the homestuck in me though?)
I think that middle/middle color might be fuschia. Also, harmonics, maybe? I notice that the frequency of violet approaches double the lower visible end of red. I'm just hypothesizing, but could the red cones get excited as violet approaches the first harmonic of red?
Just use a rainbow instead of a prism. They are they Same colors but there are a lot of images of rainbows that contain the purple. Also lasers that can change their frequency actually exist even if they skip a lot of frequencies.
Just as a heads up, a quick correction at 1:30 , wavelengths do change over time/space, just not in the left to right direction. They do shift towards red as time and space shifts, it's called redshift. It just happens over a massive scale, obv not like the picture but you get what I mean.
Yeah, I know about redshift and blueshift, but they are not relevant to digital color. It's like, if I say, "park on that side of the tree instead, because the sun is going to move this way, so it'll be in the shade," it's not relevant to respond, "Um actually it's the Earth that's moving." I mean, if we go down this route, I could Um actually the Um actually, with "well technically the sun IS moving around the galactic center, which is also moving relative to the CMBR. But we were talking about parking and have now gotten way off-topic. This is a useful analogy though, and I think I'll use it in a future video.
Taran, don't take my word for it, as this is my own intuitive perception of the violet issue, but I have the idea that our hue perception is very limited when it comes to spectral violet, compared to other colors and we evolved to hallucinate the "missing perception" as just a mix of red and blue, instead of having a larger perception into lower wavelengths for the violet hue. That's why violet and magenta are related in our color perception. I also think this is further evidenced by the fact that as @Radaos said in another comment, some people have tetrachromacy either natural or surgery-induced, which means it might be something we had fully functional in the past, but became a sort of vestigial feature, kinda like the tailbone is a vestigial tail. Another way to think about it is to look at the two ways how we perceive colors, as it can either be pure spectral or a mix of colors. Taking yellow as an example, since you mentioned it at the end of the video, we can perceive all yellow hue as either pure spectral or a mix of red and green. But with violet that doesn't happen because our pure spectral perception is incomplete (it doesn't go to UV) and our brain evolved to wrap around to red when doing color mixing, if that makes sense, instead of just continue the perception into lower wavelengths. If I'm not mistaken people with tetrachromacy do see UV wavelengths as a kind of bright light violet-ish magenta, which adds up to what I tried to explain. From an evolutionary standpoint, it was probably advantageous for us to be blind to this kind of "spectral magenta" in the UV range. Again, this is all my intuitive perception of the problem, so do take it with a grain of salt. Also, the terms I use may not be entirely accurate.
Sadly the light we used in uni for the prism was really dim and probably not even true white. So sadly those pictures I have from there are barely visible
16:35 this is an entirely layman hypothesis so probably (read: is) wrong for a number of reasons, but I'd think you answered your own question at 17:53, or rather that it's more a matter of semiotics. i.e., when we perceive pure violet light it is just that, its own distinct hue without any (additional) long-wave cone excitation, and it looks like violet, but because the sRGB color space can't access that hue it has to begin hallucinating earlier to attempt to visualize it. so, it's not actually the same color, but just an approximation. it almost makes me wonder that if we could look through the eyes of a mantis shrimp and perceive UV light, it would be our fuschia, and the human brain is just performing a similar sort of hack-job to access colors it isn't "supposed" to.
Rgb is sufficient to capture the full color wheel in terms of perception. When we see yellow on a screen thats red and green light. The spectral yellow isn't present.
@@taranvanhemert2 It is correct, Violet is a mix of Red and Blue just like Magenta, and Red and Blue are on opposite sides of the Spectrum. There for Violet can't be in the rainbow either.
Bridging the gap between the two ends of the visible light spectrum Pink is simply a light shade of red. with little to no blue mixed in. Pink. purple. magenta, and violet are often confused With one another. This infographic shows exactly how those colors differ. Purple and magenta have the sarne hue. purple is merely a darker shade Of magenta, as seen below. True violet light is made of a single wavelength (between 450 to 380 nm). whereas purple and magenta are made of two different wavelengths (red and blue.) Violet is a spectral color that appears in the and is often confused with magenta or purple, which are not spectral colors, and do not appear in the rainbow. Digital cameras do have sensitivity towards violet, but the data is saved to the blue and red channels. There is no violet channel. nor any displays with violet subpixels. Therefore, all violet colors, as seen on a computer screen, are magenta or purple, Magenta is an extra-spectral colour, meaning that it is not a hue associated with monochromatic visible light When the brain sees blue and red, but not green, it interpets it as magenta (or purple, which is just a darker shade of magenta, as shown to the right.) To see red and blue simultaneously, without your brain interpeting it as magenta, look at the two images above and cross your eyes until they overlap.
Your science is fine here but your language and color theory is off. In our eye we have three kinds of cones. Violet looks purple/magenta because it *is* magenta. We see violet because our red and blue cones are firing. Not entirely red, but just a little for some odd biology reason. But in terms of color, yes, that's magenta+blue to get the range of purples including the spectral violet. Magenta is your red and blue cones during but not green firing. This is why you get a range of red-magenta and blue-magenta. The blue-magenta range is undeniably purples. Violet, purple, I think everyone is in agreement. Now as for my complaint with your video, you simply asserted pink as light red, which is a common misconception. Pink is *not* light red, just as cyan is *not* light blue. Even your xkcd chart shows that more or less everyone considers magenta to be pink or maybe a purplish pink. In practice, the range of pinks are really ranges of magenta. Magenta is pink. Pink is magenta. The stereotypical pastel pink people know is a sort of desaturated magenta-red. So you have magenta or fuschia as the pure "pseudo-spectral" color, and then on the red side you get most pinks, and on the blue side you get purples. But fuschia and magenta, historically, were called rose, and is basically just pink.
i like this video but try not to be prescriptivist on colour names. by all means get the science correct but correcting someone for calling a colour wrong is just so, so perscriptivist
Hey Taran,... sooo multiple things:
You got the part at 13:45 wrong, and well, the image you show is also wrong, but here is how it works:
The three curves labelled L, M and S at 14:00 are the actual cone sensitivities, as you correctly stated.
The image at 13:45 shows the so called colour matching functions (CMF). They are the result of multiple studies and are created in the following way:
You have three monochromatic light sources shining at one eye, and a single monochromatic light for the other eye. The single light is stepped through all wavelengths. The human test subject is now tasked to adjust the three monochromatic lights so, that they match the single one. Out of that you get the intensities of the three wavelengths you set as primary colors that you need to combine to get any single one wavelength color.
I had to work through this for my master thesis in photonics and my god, its easy to mess up along the way. If you need a good source for all the base data and honestly one of the best explanations for all the scientific background go to "The Colour & Vision Research laboratory and database" cvrl. It goes all the way to the scientific base of how these functions are made and where they come from.
While cvrl goes into the human aspect of the colorimetry, a site that covers basically all the computational part of it is "bruce lindbloom" (hard to convey the site name when its literally just his name,... just google the name and you should find it).
Finally as for the image of a prism you can find one if you search on Wikimedia commons with the query "Színszóródás prizmán2", its sadly not in the PD and feels off, but it shows the purple you're searching for.
In any case, love your videos about color and graphics.
Let's try this again, and hope UA-cam doesnt take this as spam:
The thing you talk about at 16:05 can be explained by the CMFs from my main comment. While yes, there are pure wavelengths that look violet, all of our colour science is built on the three primaries, and to make violet we use the combination of the red and blue. Because of this you can remove the red part of the violet.
The reason there are so little photos of prisms that show actual violet could be because of multiple reason. First, they could have used a lightsource to make the photo, that is not hot enough to produce meaningful amounts of violet/UV radiation. The second reason is the glass the prism is made out of. Most standard types of glass basically don't transmit UV-radiation and can have a hard time with violet already. If you want some examples for transmittance curves of glass prisms you can look at the "ThorLabs" shop with the search query "Equilateral Dispersive Prisms". A way to get around that limitation of the transmittance is the use of an optical grating, since it doesn't necessarily transmits through a glass medium. I cant post the link to the image here but you should be able to find it by searching on "fineartamerica" for "light dispersed by diffraction grating". Now this is obviously not in the public domain, but it should be a good image to use as a reference for how these things can look.
Hyped to find out why magenta is not pink!!!
Please make more informational videos like these 🥺, this type of video is just elite level UA-cam content.
This alongside your colour correction series and the upscaling video are tremendously helpful and informative.
Thank you sir 🙏
Saw this on Nebula. At 17:00 Taran asks what if humans had 4 cones in the eye. Some people do. Human tetrachromacy is rare, but it does occur in two ways. Naturally occurring tetrachromacy happens only in women. Near-UV tetrachromacy can occur after lens replacement surgery. There's an article on Extremetech about this.
Taran the way you and your wife bicker is soooooo cute
Awww, thanks! We love to bicker like that. After about 3 years together, we still have not had any real fights. We are always randomly hugging and kissing each other during the day. I've never loved someone so much.
Captain Disillusion explained this topic very well in the CD / Color episode
I love that pedantic videos about color representations are becoming common enough to be A type of video I enjoy.
Technology Connections video about brown is A classic!
There sort of are tunable lasers, a supercontinum laser with an optoacoustic filter is how ive seen les of "Les' lab" here on youtube do it, hugens optics also has some similar cool optics shenanigans, love the videos, looking forwards to more and hearing how things have been post LMG
taran and i have the same petty obsessions with color. I knew the content but still watched.
Shocking pink is magenta, got it
It's nice to see someone else with so many Bricklink tabs open at all times
Anyways, people call pink "magenta" in common sense...
This was the clearest, most understandable explanation of this topic.
Taran ranting about colours again? Surely content deserving of being placed on the first channel.
Love watching these with my colourblindness, flipping on a filter every now and then. (I've never truly seen purple, looks like a dark blue most of the time.)
At 7:33 with no filter, I don't see any hint of red beyond 1/3, 1/2 and 1/4 of those bars.
With a filter, it looks like there might be a red component to 1/2, 2/3 and 1/3 of them, with the last bar doing *something* in the middle.
I love kinds of videos on topics where you could probably keep digging and digging and still there'll be something you missed or don't understand. Nature really is weird.
Only Taran would make this video
I know it's gonna be good when it "starts with the electromagnetic spectrum"
Focusing on the blus and red diagrams has really fucken my colour perception, both my eyes are now seeing different things one is warm the other is cold but the world as whole is bluer
My favorite color :y
(Specifically the way the colors mix in the middle bar is closest to my favorite but they’re all bangers. I think most people call that middle one fuchsia. Maybe that’s just the homestuck in me though?)
Have you by any chance listened to radio lab's classic episode about color? They covered the extra cones problem
I think that middle/middle color might be fuschia. Also, harmonics, maybe? I notice that the frequency of violet approaches double the lower visible end of red. I'm just hypothesizing, but could the red cones get excited as violet approaches the first harmonic of red?
Magenta and fuschia are the same color and they're both pink
@@Otome_chan311 you just named three completely different colors.
@@marsrevolutionarymagenta and fuschia are literally synonyms in English. Pink is indeed more broad. Magenta is a specific type of pink.
@@Otome_chan311 except that they aren't. They are all different colors within a narrow spectrum.
absolute banger of a video my guy
Now *this*, I'm excited for.
Just use a rainbow instead of a prism. They are they Same colors but there are a lot of images of rainbows that contain the purple.
Also lasers that can change their frequency actually exist even if they skip a lot of frequencies.
comment reminding me to check for a prism
i've heard the red cells also slightly detect high frequency (violet) and that's why
Just as a heads up, a quick correction at 1:30 , wavelengths do change over time/space, just not in the left to right direction. They do shift towards red as time and space shifts, it's called redshift. It just happens over a massive scale, obv not like the picture but you get what I mean.
Yeah, I know about redshift and blueshift, but they are not relevant to digital color. It's like, if I say, "park on that side of the tree instead, because the sun is going to move this way, so it'll be in the shade," it's not relevant to respond, "Um actually it's the Earth that's moving."
I mean, if we go down this route, I could Um actually the Um actually, with "well technically the sun IS moving around the galactic center, which is also moving relative to the CMBR.
But we were talking about parking and have now gotten way off-topic.
This is a useful analogy though, and I think I'll use it in a future video.
Taran, don't take my word for it, as this is my own intuitive perception of the violet issue, but I have the idea that our hue perception is very limited when it comes to spectral violet, compared to other colors and we evolved to hallucinate the "missing perception" as just a mix of red and blue, instead of having a larger perception into lower wavelengths for the violet hue. That's why violet and magenta are related in our color perception.
I also think this is further evidenced by the fact that as @Radaos said in another comment, some people have tetrachromacy either natural or surgery-induced, which means it might be something we had fully functional in the past, but became a sort of vestigial feature, kinda like the tailbone is a vestigial tail.
Another way to think about it is to look at the two ways how we perceive colors, as it can either be pure spectral or a mix of colors. Taking yellow as an example, since you mentioned it at the end of the video, we can perceive all yellow hue as either pure spectral or a mix of red and green. But with violet that doesn't happen because our pure spectral perception is incomplete (it doesn't go to UV) and our brain evolved to wrap around to red when doing color mixing, if that makes sense, instead of just continue the perception into lower wavelengths.
If I'm not mistaken people with tetrachromacy do see UV wavelengths as a kind of bright light violet-ish magenta, which adds up to what I tried to explain. From an evolutionary standpoint, it was probably advantageous for us to be blind to this kind of "spectral magenta" in the UV range.
Again, this is all my intuitive perception of the problem, so do take it with a grain of salt. Also, the terms I use may not be entirely accurate.
Sadly the light we used in uni for the prism was really dim and probably not even true white. So sadly those pictures I have from there are barely visible
16:35 this is an entirely layman hypothesis so probably (read: is) wrong for a number of reasons, but I'd think you answered your own question at 17:53, or rather that it's more a matter of semiotics. i.e., when we perceive pure violet light it is just that, its own distinct hue without any (additional) long-wave cone excitation, and it looks like violet, but because the sRGB color space can't access that hue it has to begin hallucinating earlier to attempt to visualize it. so, it's not actually the same color, but just an approximation. it almost makes me wonder that if we could look through the eyes of a mantis shrimp and perceive UV light, it would be our fuschia, and the human brain is just performing a similar sort of hack-job to access colors it isn't "supposed" to.
1:30 Doppler effect/Red shift exist, so what you said is not entirely true
I would like to thank your wife for inspiring this video hehe.
I'm colorblind and I have absolutely no idea why I'm watching this...but I love it!
Are you completely colorblind? Do you see absolutely no color atall?
So we need a monitor with RYGBVW sub pixels
Rgb is sufficient to capture the full color wheel in terms of perception. When we see yellow on a screen thats red and green light. The spectral yellow isn't present.
your display is RGB
Love the Barbie thumbnail
13:26 or maybe it's because Violet is also not a spectral color either, Violet is also a combination of Red and Blue light.
This is incorrect.
@@taranvanhemert2 It is correct, Violet is a mix of Red and Blue just like Magenta, and Red and Blue are on opposite sides of the Spectrum. There for Violet can't be in the rainbow either.
@@nickytembo4112 ok zoomer
@@taranvanhemert2 Thanks for saying that Purple is a dark Magenta.
Violet is a spectral color that triggers both red and blue cones.
Magenta is magenta, pink is pink. I never saw a pink ink cartridge, therefore magenta is not pink. Why a 20 minutes video?
That's like saying lime isn't green.
Bridging the gap between the two ends
of the visible light spectrum
Pink is simply a light
shade of red. with little
to no blue mixed in.
Pink. purple. magenta, and violet are often
confused With one another. This infographic
shows exactly how those colors differ.
Purple and magenta have the sarne hue.
purple is merely a darker shade Of
magenta, as seen below.
True violet light is made of a single
wavelength (between 450 to 380 nm).
whereas purple and magenta are made of
two different wavelengths (red and blue.)
Violet is a spectral color that appears in the
and is often confused with magenta or
purple, which are not spectral colors, and do not
appear in the rainbow.
Digital cameras do have sensitivity towards violet,
but the data is saved to the blue and red channels.
There is no violet channel. nor any displays with
violet subpixels. Therefore, all violet colors, as
seen on a computer screen, are
magenta or purple,
Magenta is an extra-spectral colour, meaning that it is
not a hue associated with monochromatic visible light
When the brain sees blue and red, but not green, it
interpets it as magenta (or purple, which is just a darker
shade of magenta, as shown to the right.)
To see red and blue simultaneously, without your brain
interpeting it as magenta, look at the two images above
and cross your eyes until they overlap.
this was grabbed using one of the windows powertoys, super nifty feature
Because of the formatting I started reading this as a poem and then realized it's just a regular text lol.
This is a category 5 autism event
its pinkenta
Your science is fine here but your language and color theory is off. In our eye we have three kinds of cones. Violet looks purple/magenta because it *is* magenta. We see violet because our red and blue cones are firing. Not entirely red, but just a little for some odd biology reason. But in terms of color, yes, that's magenta+blue to get the range of purples including the spectral violet.
Magenta is your red and blue cones during but not green firing. This is why you get a range of red-magenta and blue-magenta. The blue-magenta range is undeniably purples. Violet, purple, I think everyone is in agreement.
Now as for my complaint with your video, you simply asserted pink as light red, which is a common misconception. Pink is *not* light red, just as cyan is *not* light blue. Even your xkcd chart shows that more or less everyone considers magenta to be pink or maybe a purplish pink. In practice, the range of pinks are really ranges of magenta. Magenta is pink. Pink is magenta. The stereotypical pastel pink people know is a sort of desaturated magenta-red. So you have magenta or fuschia as the pure "pseudo-spectral" color, and then on the red side you get most pinks, and on the blue side you get purples.
But fuschia and magenta, historically, were called rose, and is basically just pink.
i like this video but try not to be prescriptivist on colour names. by all means get the science correct but correcting someone for calling a colour wrong is just so, so perscriptivist
Just so you know, cause there are no dislike counts on youtube comments, I disliked your comment.
@@Protegit Every like of your comment is a dislike of the parent comment