Why you can't take a good picture of a rainbow
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- čas přidán 18. 09. 2019
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There's a mismatch between the sensitivity of colour pixels in a digital camera sensor and the sensitivity of colour sensing cells in the human eye. We don't normally notice until we try to take a picture of the whole visible spectrum (like in a rainbow!). For example if you take a picture of a rainbow with a goPro Hero 7 violet disappears!
I also talk about how computer screens can show violet even though the pixels only go as far as blue.
Here's my video about how cones cells work:
• Vision Is Actually A C...
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I hope you faked those credit card credentials!
Still no Linux client, so...
free on my _fist_ device, Steve?
@@thoperSought that's what I call my phone.
@@AgentM124 I didn't. But someone did!
Watching this as a mildly colourblind person is even more fun. "You think this is yellow " nah mate pretty sure thats green
If you’re female, there’s a chance you’re tetrachromatic
Most people _are_ tetrachromats, because rods have a different spectral sensitivity from any of the cones, it's just that we don't have many rods in the middle of our retina. And yes, some studies suggest that some people (mostly women, but also some men) have four cone types, but the fourth type just overlaps the spectral range of the "red" and "green" cones, so those people don't actually see _more_ colours in the sense of a greater spectral range, they are just a bit better at distinguishing similar shades of yellow / brown.
@@clarenceclarence9529 If you're a male, there's also a chance that you're tetrachromatic
Just a question - what does the Bangladesh flag look like to you?
I'm a guy and I see 16 colours
Watched the whole video not realising my phone's blue light filter was on, now I gotta watch it all again
oh fuck. one of the few times where the video is so interesting I don't go into the comments and I miss out on something very important 😂😂
I got night mode on.
Same here 😂
Holy sh*t, thankss
You can avoid this by watching only the blue part.
I just realized at 6:25 that this quirk of biochemistry explains, why we experience color on a circle rather than just a line...
Wow, didn't know you were here. Thank you for the creative and quite helpful math songs, they really help.
What?
@@GMC997 can u explain that? I don't get it
@@greengreen1780 He's a german math CZcamsr which is known for his very catchy math songs.
@@GMC997 Thanks for pointing this out; I like finding mathematically helpful things :)
I’m colorblind and those expensive color correcting sunglasses I bought online show me a more brilliant green than I’ve ever seen before, and purple is an entirely new color to me! It always just looked blue. Interesting how the brain can be tricked into seeing colors that have always been there, but unseen! I hope I live long enough to see the day that getting fitted for prescription glasses will include color correction as well. Also, it’s totally understandable to see CZcams videos of colorblind people putting on these glasses for the first time and breaking down in tears from the emotion of it all!
I'm glad you can see purple now! It's my favorite color
as someone who is also colorblind- i dont experience a feeling with that much emotion. My experience with those color filter glasses is that it extenuates the vibrancy of some colors which help me find the difference. Wild how it can work sometimes!
I know someone who sees a certain darker shade of blue and calls it purple, (or was it a certain type of purple that she called blue?)! I would have called it blue with a slight hint of something in between indigo and violet. I have a problem with brilliant bright red. It's too intense so I don't like looking at too much red like being behind a red car.
If I had a job washing cars I'd refuse it if the car is red or intense pink or bright orange or if it was parked in a sunny place! Too bright even with polaroids on. I don't want red things in my house but have to make a few exceptions for strawberries, tomato ketchup, tomato soup is not so bad as it has yellow mixed in, and raspberries are not so bad as they have a slight tinge of purple (Colgate toothpaste... I try not to look at the tube!). Someone painted a wall in town centre intense red and if I go near it I have to shield my eyes and look down and away from it. I'm glad the opposite wall (on the stairs) is black and white so I don't have to hide my eyes from seeing in both directions!)
It puts me off watching certain TV shows due to oversaturated red in the studio (unless I turn the colour down to a tolerable level, which makes the faces pale grey!) It's almost as bad on screens with oversaturated blue, magenta or green. In-between colours are much more tolerable. Yellow and cyan are OK but I'd prefer more natural looking colours that are more of a mixture.
I ain't colorblind but going from a display with a bad color range to one with a good one is amazing to me
i can't even begin to imagine how amazing it must be to have your own eyes get an improved color reproduction
That reply was for @yahccs1
"The Real World - it's a terrifying place, but it has rainbows!"
Can you make that into a shirt?
This is not an idle request!
I too would like a shirt with that on it!
Just make it your self there are enough websites out there for that
I can and I will. I'll post back here when it's ready.
This has a double meaning, BE CAREFULL !! 😂
I like the use of the grinch as the green cone.
Greench
I like the use of Bad Dragon products for the red and blue cones. ( ͡° ͜ʖ ͡°)
He could have also used a Smurf for blue and a red Pikmin for red...
@@MajatekYT LOL Don't ask, don't tell 😉
@@MajatekYT Someone had to! LMAO
Actually, the long-wavelength (L) cones do not have a bump at short wavelengths, but their short wave response tails off much more gradually than the short-wavelength (S) cones. This means that the ratio of S to L response is maximum somewhere on the short wavelength side of the L cone response peak, but as you go to even shorter (violet) wavelengths, the ratio of S/L decreases, even though the S response is still stronger. This reduction in the S/L ratio moves the perceived hue towards magenta. meanwhile, on the long-wavelength side of the S peak, the middle (M) cones pull the hue toward cyan, even though the L response is still rising. The curves with a bump are linearly matrixed responses of the actual (bump-less) cone responses, used to make the useful CIE color diagrams. Digital camera responses are typical somewhat different from cone responses or even a linear matrix of cone responses (being too narrow), but can be close enough to be mathematically matrixed to record violet as purplish.
Color film responses have been and typically are even narrower than digital camera responses and will reproduce the spectrum as sharply defined bands of red, green, and blue. This was useful, as it increased the color saturation of most ordinary objects to compensate for the lack of saturation in the dyes of the print or transparency. In a digital system, the color signals can be mathematically manipulated to get the right saturation and hue, at least for things that do not have odd spectra (like your fluorescent bulbs). With color film, common fluorescent bulbs were always a problem, as they photographed as greenish.
If CZcams valued truth this comment would have all the likes. When Mould talked about RBG cones I was shaking my head, so “no S, M, L, and you wouldn’t believe how much M and L overlap…”. Anyway thanks for your informative comment
It is too early on a Sunday to try and read thru your comment lol
Definitely sounds like something that could have just spontaneously evolved from random blind mutations 👀
Oh my God! That the SECOND time Steve's been wrong!
@@GordonKindlmannIn Steve's defense, he gives a disclaimer at the 2:50 mark. "For this video I'm going to actually over-simplify things... for this video, let's just say we've got three types of cone cells, and we're going to call them 'red' cone cells, 'green' cone cells, and 'blue' cone cells." :D
This was one of the 1st lessons we learned in color photo class (though it was back in the age of film). We included a standard grey card in different lighting conditions to watch how everything got messed up and cast weirdly.
"Just have a think about something and go, 'yeah, that's probably true'." That's a difficult temptation to resist. Great video. Never stop.
please
@Justin O'Brien The earth is at the "center" of the universe. Course so is everywhere else ;)
It's a pretty good 80:20 if your thinking is solid enough.
*Aristotle has joined the chat*
I'm pretty sure I also "worked out" this "fact" and told people. Without actual evidence.
5:01 rare live footage of a nerd discovering the world
(me included)
discovering the outside*
He probably filmed it with the GoPro... which ironically canNOT detect the violet he mentioned there.
@@Megalomaniakaal outside?
@@coffeecatrailway The Big Blue Room. You've probably been there, even if by accident. They have super bright lights on during the day and then turn them off at night but leave in some smaller nightlights. But during the winter they tend to leave the main lights off a lot longer and they turn down the heating, too. Also, I haven't figured out the schedule, but they test the fire suppression sprinklers from time to time, too.
Ha ha ha... :D
2:08 That's the whole budget for the video right there
Your videos are always incredibly thought out. Keep up the good work!
In Newton's time, what we now call Cyan was then called Blue, and what we now call Blue was then called Indigo. That kinda explains why there's so much of a gap between Green and Blue in that ROY G BIV thing. Also why Indigo and Violet seem so close together.
So a modern version of those colors in that order might be Red, Orange, Yellow, Green, Cyan, Blue, Violet.
...or so I've been told.
Actually it was originally ROY G BV with no Indigo at all but indeed Blue meant what we now call Cyan and Violet meant what we now call Dark Blue. Later a composer wanted to make the colours of the rainbow fit the musical scale 'do re me' of which there are seven and so added Indigo to the rainbow referring to Light Blue.
The Blue-Cyan thing makes a lot of sense, we always say "the sky is blue" while it's clearly Cyan, this might be an old remnant of that time we called cyan blue.
@@GamingGal556 According to this abstract - www.sciencedirect.com/science/article/abs/pii/0039368190900265 - which cites Newton's publication of his Optics from 1704 and his Optical Lectures originally delivered 1670-1672 and published in the 1980s, Newton originally only distinguished 5 colours, but added orange and indigo at some point in the intervening 30+ years. Comparing his diagrams showing the distribution of colours across the spectrum with an actual spectrum, his "blue" looks cyan to modern eyes, and his "indigo" region is where we would put blue.
@@rmsgrey A big part of Newton choosing the number of colors is due to his belief that the color spectrum should follow the musical scale. www.the-scientist.com/foundations/newtons-color-theory-ca-1665-31931
You could 'distinguish' as many colors as you want. The distinction of a number of colors in a Mk1 Eyeball is completely arbitrary.
Also "violet" in the color spectrum doesn't mean "purple" like we think of it today. Newton's violet was dark blue. As in the old poem "VIOLETS are BLUE".
@@doggonemess1 Why are people putting so much into what Newton discovered? It's not like we can't look into a spectroscope ourselves to see what the colors actually look like. I have done this, and I can tell you that violet really does look purplish. It's not just dark blue. I know that my subjective experience cannot speak for everyone, but many people seem to agree with the existence of a purple-like color in violet, so I don't know why some people deny its existence.
The most amazing revelation of the video... that the sun was out in England long enough for Steve to be able to film a rainbow from a garden hose.
The comic strip Viking Hagar the Horrible once described England:
If you like the weather, you’ll LOVE the cooking!
I saw a patch of violets in a garden once and was caught off-guard by just how... VIOLET they were. It was like experiencing a new colour, it just looked wrong. I assumed it was like you said, screens can't show violet properly. But now I think about it, what's more likely is that the range of possible colours is just slightly bigger than what can be displayed on this cheap old monitor I've been staring at for so long... Considering I've had the exact same feeling when seeing flowers in other colours.
If you use Kodak Ectacrome slide film you get all of the colors that the human eye can detect. It has always been considered the most accurate daylight film. I really fell in love with it because it came in a 1000 speed daylight for sport or nature photography, and a 1000 speed tungsten for theatrical photography. I got incredible color shots of concerts that appeared exactly as they looked , tungsten gave kodachrome an orange cast that the ectacrome compensated for.
I always wondered about why we learn about a color circle even though the electro magnetic spectrum is clearly not circular.
*Red cone cells have a second sensitivity bump is why!* =D
Awesome man! Thanks, I get it
because it is more useful in art
Because it can be with light and your eye
They still aren't a circle. More like a kind of slanted oval horseshoeish kinda shape.
I'm more worried about why the fuck I was taught that the prime colors are red, blue and yellow. In a absolutely no cases is this correct. It's either red, green and blue, or yellow, magenta and cyan.
This is on par with the common myth we learned about which areas of your tongue can taste different things. It's all just bullocks.
THANK YOU!! I think you just solved my constant colour-correction frustration. Off to buy some LED bulbs.
Yay! Hope it works out. Look for a panel with a high cri value.
The issue with the CFL bulbs made me think of the fake Smarter Every Day segment from a Captain Disillusion video, where he adjusts the white balance of the camera to get the right green off a calibrated green screen. Any chance that’s what’s going on here: that you need to shoot in a specific white balance with those lights? Here’s the Captain D video: czcams.com/video/aO3JgPUJ6iQ/video.html
Thing is, florescents have always photographed with a heavy green bias. No reason to think CFLs wouldn't do the same.
I'm late in the game, but I did a spectrum analysis of my bulbs at home and found that IKEAs bulbs were the cheapest ones that still produced a good light distribution. Many cheap LEDs fake it by emitting light in the same way Steve's CFLs do. Not only that, they use cheap electronics and as a result they flicker like crazy.
USA is so weird, why does anyone buy anything else than LED's in 21st century?
Like everyone agrees it's better... right?
Showing comfort and ease with being wrong is such a nice human quality, and makes for the best science.
Looking at those frequency absorption curves, I think you were right that monitors can't reproduce violet properly. True violet would trigger the red and blue cones, as you said, but the red pixels on a monitor would *also* trigger the green cones, due to how much those curves overlap.
That's an interesting point that I wouldn't have thought of. I wonder how much an effect it actually has to our brains. Perhaps a 'less vivid' violet?
Having a CIE chart showing the possible perceived colors and a gamut triangle for a tv/monitor makes this a lot more clear.
Edit: I used to work for a company that made colorimeters. I think you could do a whole video on the CIE chart and how it works.
Technology Connections did a great video about this recently: "The Weird World in RGB"
I was about to comment the same :) 2 hours to late
Same, more hours late. To me that was the definitive best explanation demo combo for that phenomena that I've seen.
@@tehguitarque Well I'm just embarrassingly late
@@TechnologyConnections WE ARE NOT WORTHY!
Technology Connections woah now that’s a crossover I haven’t seen before
Oh wow, Steve! I was really hoping you'd tell about that second sensitivity bump in red cone cells. It's very poorly documented online and I was never quite sure if was actually true. Thank you for this video.
I’ve been a house painter for 44 yrs and I always just thought white wasn’t actually a colour per say. I had the idea it’s what your left with when no colour is present is white (the fact that all colour in paint is provided by a tint to make so many coulours). But that flashlight example of the 3 primary colours making white blew my mind, now I can’t ever see white the same again. Right when you think you can’t be surprised and learn anything new, TaDa, I was wrong, which is a welcome experience. Thx for that Steve.
Time to start a conspiracy channel about "Big Magenta" and the plot to deny us access to the truth about violet.
Magenta takes off it's mask. *gasps* It's violet. "Heh, heh, heh. You fools! I was violet all along."
@@JNCressey you thought it was magenta, but it was me, Dio!
I've always wondered why no one ever talks about the weirdness of violet. Minute Physics outright denies its existence in *two* of his videos!
@@DANGJOS Ugh, I remember arguing in one of those videos. They got colors completely wrong.
@@frechjo Yeah. And just to update, I've learned a lot more about color science since I last posted that comment. I think I'm closing in on the mystery of violet.
I was filming fairy basslets, a brilliantly purple fish, on a dive trip over the summer with an old GoPro 4 and was very disappointed when it didn't capture the vivid color. Now I know why
Nice to get some real world validation!
"Action cameras" have notoriously bad colour "gamuts" (not really the technically correct term, but it'll do), for a mix of different reasons, related to both the sensor itself and the lenses (ex., they try to filter out UV light to reduce hazing, but end up filtering out regular violet light as well, and the sensors are often designed to see better in the dark, at the cost of good colour reproduction).
Use a good video camera (or even a mid-range DSLR) and you should get much better results (remember you'll also be limited by the gamut of the monitor used to watch the footage afterwards).
Excellent piece of info about colors!!! Really rounds out the info I had found about the fact that there are no browns and no magenta wavelengths. Super cool stuff!
Caveat on "looking green" bit, that kinda edges into color testing. Between my eyesight & how I had my monitor, only your wall got limed. Still, fascinating -- especially about the extra "red bump" in how our eyes work. Thanks for that, glad I found your channel!
I keep forgetting the UK calls flashlights "torches", I though you were gonna pull out some actual fire.
Actually the USA calls torches "flashlights". Why do you think the language is called "English"?
@@Gribbo9999 Precisely, there's no such thing as a "flashlight", any light that flashes is a strobe light (or a blinker if it's on your car)
@@logix8969 When people from the UK stop calling PA systems 'Tannoys', sticky tape 'Sellotape', aluminium cans 'tins', aluminium foil 'tinfoil', vacuum cleaners 'Hoovers', and so on and so forth - only then will you have a basis for complaining about how the English language is used in other countries. Language is as it is used, not as you want it to be and not as it used to be in the past. Language is performative and in constant flux, so it is an utter waste of time trying to hold the waters back.
@@Auriflamme Wow, sorry snowflake! Considering it's our language...
@@Gribbo9999 Lol
The sponsorship testimonial anecdote was better than the main subject (in my opinion)! Brilliant!
You are brilliant always love the shows thank you Steve.
Great video as Always @Steve Mould
Back in my teen days i played pc games, and my favorite ones were rally games. One especially (RBR), even made modding possible. And i tried to give new skins to the so loved Subaru Imprezas. I tried everything to copy that nice glowing yellow-green of their logo, and nothing worked. It took me a long time to learn, that we can't reproduce that color on monitors. As i've heard, it is because actual UV light makes it so bright for our eyes, but i'm not sure. Can you make a video about it? Not because i couldn't research it myself (will do in a moment now that i got reminded), but it might be an interesting topic to cover. Why do visibility vests are so bright? (not the reflective straps, just the green/orange)
That is fluorescence. The ink convert violet light and ultraviolet to red, yellow or green. Our eyes are less sensitive to violet and near infrared than the other colors. By converting violet and reflecting green/red at the same time the color will appear more bright than the others.
You can reproduce it on monitors, but the game engine probably could not. In regular coloured objects the amount of light of a particular color coming off an object depends on the amount of light of that color hitting it.
In fluorescent materials, the amount of light of a particular color can depend on the amount of other, high wavelength light too, usually blue and up.
Meaning the amount of light of a particular color coming out can be >100% of the light hitting it, which makes it look weird to the eye.
In a pinch, you would probably fake it by making the percentage of yellow light reflected be say 110% or 120% to get a similar effect, or a special "fluorescence shader" if you want more accurate results.
But the game engine likely only supported reflectivities that are
Try going outside at dusk with brightly coloured clothing and you might notice the same effect. It's caused by fluorescence. When objects reflect light, the atoms are absorbing specific frequencies of light which cause the electrons to jump up into an excited state before falling back down and re-emitting that same frequency. As you go from red to violet and beyond to UV, the frequency increases, and so does the energy and therefore the size of the jump the electron does. Some materials have multiple levels aligned such that they can absorb UV and have a big electron jump, skipping over a level. The electron then falls back to the middle level, emitting an invisible (IR) low energy photon, then falls the rest of the way back and emits a visible photon. This extra boost from this visible colour is what makes fluorescence clothing look so bright.
Not only does it literally glow, it glows a frequency of yellow that our red and green cones are particularly sensitive to, which makes it even more visible compared to red+green.
there's also the fact that most color gamuts can't represent very close to full contrast mono-chromatic green: en.m.wikipedia.org/wiki/SRGB
That second red bump explains why the colour wheel works! It creates the smooth transition from red to blue, when of course those colours couldn't be farther from each other in the spectrum of visible light. :) I love how I learn something in every one of your videos!
It's late (after 3:30 AM) and I don't have the energy to properly respond to this video right now, but even THAT is wrong. THERE IS NO SECOND BUMP. The second bump is an artifact of using the XYZ color matching functions, which were a proposal for how the 3 cone types behaved which turned out to be incorrect.
The XYZ functions DID turn out to be a Linear Combination of the three cone's true response functions (the 'cone fundamentals'), and it's also true that there's a 'second bump' when looking at the raw pigment's response functions... But THAT 'second bump' is muuch closer to the primary bump, and all three cones have it if you want to be technically correct.
The reason why those 'secondary bumps' don't really show up in the actual 'cone fundamentals' is because the lenses in our eyes, as well as the pigment in the macula, filter out higher frequencies/shorter wavelengths, so our overall response to those frequencies/wavelengths is diminished.
The end result is that the effective response for each cone type to light of each wavelength, looks like THIS:
www.cvrl.org/pngimages/linss2_10e_fine.png
Tomorrow, if I remember to, I'll watch his second video so I can determine how mad at him I should be for continuing to spread false information, and potentially type up a much longer rant.
@@Tynach They're not exactly red, green, and blue, either. But there's still an aberration at the extreme left of red, which is like a bump.
@@Tynach Pretty clearly, then, the brain sees blue when a mixture of blue and red cones are stimulated, and sees violet when only the blue cones are stimulated. Rather the opposite of one's intuition, but that's what the cone sensitivity diagram is telling us.
@@jpdemer5 No, when a mixture of 'blue' (S cone) and 'green' (M cone) are stimulated. That's when we see blue.
@@robinhodson9890 CZcams isn't letting me post a link to the actual LMS chart, but if you look up the CIE 2006 LMS cone spectral sensitivities, you'll find there is no bump. That is, the curve has only one single peak, and from that peak on both sides it only goes down in value, never back up again.
I've studied these curves extensively for the last few years, and I know for sure there is no bump.
Wow, that was a really slick way to plug your sponsor! Nicely done!
What your describing is the concept of color temperature in lighting for television and film and white balancing to correct for those conditions. Every lighting element has these characteristics to consider. Great Video. - MM in Denver CO
0:40 ahhh Steve forgot to click 'Analyse' rookie mistake!
FYI: LED RGB lights have issues in the yellow orange area, which causes issues for cameras. This can be partly addressed by adding amber: RGBA, or using white LEDs and adding gels, as usually used in film production situations.
Good on you, I have much respect for you
So much so! That I really look forward to finding a video of you from the future
specifically addressing at least one thing from one of my previous comments on another video
Just please be very careful and witty about how you present the informationexactly, if you do choose to make a correction after doing the proper research..
AS TO NOT END UP ON THE CENSORSHIP* RADAR
If you remember, they spend trillions and trillions of dollars and billions of man hours...
To support, their! Pseudoscience..
For nefarious reasons..
so they will stop at nothing to keep those truths hidden that I have brought to your attention
😕
But creatively and cautiously, it can be done ☺️
LASTLY, HAVE YOU EVER CHECKED OUT THE CHANNEL THAT NO LONGER EXISTS, KNOWN AS ASAPSCIENCE...
IT IS QUITE INFORMATIVE AND QUICK...
ALSO, THE GUY WHO PAINTS HALF OF HIS FACE WITH SILVER PAINT, DOES A DECENT JOB, HELPING TO EDUCATE THE POPULIST
He also is a lot confused, about the pseudo-sciences
But I can't hold it against everybody, I am turning 40 now and didn't learn about all of the deceit!
Until my mid to early 30s
Yet another fantastic video. Thank you.
I love how he says, you might know, instead of assuming that we either already know or don't know at all. And then explains it anyway. Super polite and useful
We call those sensor pixels "Sensels" in the industry. It's not very common outside closed doors. This was good stuff, as always.
Not sure if anyone else noticed but when you turned your soft box on, the white wall behind you turned to a hint of green too. Super awesome vid buy the way. Saw you on @smartereveryday. Decided to check your channel out. You are a clear communicator and so far the two videos I've watched were very interesting. I now understand gravity waves and visible light better. Thanks
Ah, finally! That's it! Thank you so much for explaining it so clearly and in detail. I couldn't figure out why, as gorgeous as some rainbows are, they never look spectacular in photos. Great info. Peace.
So now wait a minute... I've been told Magenta is a quirk of human perception of seeing blue and red light but not green... What if what we're really seeing is violet? IE, the human eye normally sees violet as a mixture of red and blue cones, and it doesn't really matter whether it's the low-end of the red cone's range or the high end.
The other possibility is that you were right, and computers can't generate violet but only magenta... and that humans don't actually see violet either, but we're really just substituting with magenta. Violet as an individual color might well be as invisible or unacceptable as ultraviolet or infrared... but the human eye has a quirk to detect it's presence, without actually perceiving it's real color.
There is no "real" colour, colour is perception
There is no magenta in a rainbow (Violet is blue). I at least have never seen it in real life rainbows.
Magenta is no querk, it is by definition the sensation of exitation of the blue and red receptors. You cannot make a magenta lazer, but it is real.
Anyway, there is no need for the red receptor to be excited at high frequencies, because there is just not purple there to see.
@@YoniMek I have a Violet laser. It looks magenta. It's a single wavelength of light. So, yes, purple (or magenta or violet) does exist in the spectrum.
@@Estr0Vi what about red-magenta? I'd reckon there's no frequency for that, you need considerably more red than blue.
@@rarebeeph1783 Specific shades of purple and magenta would be non-spectral, but so is chartreuse and salmon, and basically all the colors we interact with every day.
...but you are still "wrong" on how the eye senses color (but you DO have the "red" second peak right). You miss an important detail on the "red" cone, which is NOT tuned to "red" light. Its peak is tuned to "yellow green" (560nM) light, versus "green" cone, tuned at 530nM, only 30 nM away! Is is a miracle that you can sense red light at all! Only because the shape of the skirts of the "green" and "red" cones are we able to sense "red" color at all. This gives the eye better low-light sensitivity, as there are 2 sets of cones sensitive to it.
You are not the only one with this oversight. It is the reason it took so long for a filter to be developed to improve color vision for those with "red-green colorblindness".
Regarding the violet flowers: they are not violet! They have a dye that absorbs green light, so the light reflected is indeed magenta. Whip out that spectroscope and view light reflected from the violet.
well as he said, he really simplififed it in this video because he's making one that goes way more in depth :P
Can you briefly explain how the filter (for colorblind people) works ?
@@user-cy3jb6ri1z Principle is simple (but the implementation is complex). Most "colorblind" people have 3 sets of cones working, but the spectral peak of one of them is shifted so the (already large) overlap with another is even more than normal. This most commonly occurs between the M & L cones. This causes the overlapped ones to have similar responses. Enchroma colorblind filter attenuates light in this overlap region, accenting the differences in the stimulation.
What Steve doesn't mention is that most "worldly" light is broad band in nature, having SLOPED sides, including that from RGB screen, so the "red & the "green" sub pixels DO contain "yellow" light. So the notched filter EFFECTIVELY "moves" the spectral responses of the 2 largely-overlapping cones apart.
The exception to this is for laser (narrow band) sources, so the "colorblind filter" does not affect the perceived color of those, unless 2 different lasers are combined.
It is explained here: enchroma.com/pages/how-enchroma-glasses-work
And the explanation is oversimplified! The filter is not a square notch as illustrated. The filter has a smooth curve (it is not practical to make such a "square" filter!)
@@bpark10001 Thank you for the explanation! I did not find detailed info by the URL and still have some questions. So the filter just removes some light that in a certain range of wavelengths (the peak of two overlapping) ? Or it shifts wavelengths apart like red light to the right and green to the left on diagram (increase and decrease wavelengths) ?
@@user-cy3jb6ri1z Filters cannot shift wavelengths; they can only attenuate them, more or less, versus wavelength. The "shift" is only apparent. If you look at a mathematical curve that has sloped sides, adjusting parts of the curve up & down has the same effect as moving it sideways. This technique is widely used in engineering. For example, on a camshaft driving a valve in an engine, the opening time of the valve can be changed by changing the length of the linkage to the cam.
This scheme only works if the spectral response shape of the eye's cones has sloped sides, & the spectral shape of the incoming light is also sloped. By attenuating more on one side of the curve, & less on the other, the curve is effectively spectrally shifted.
Another way to think of this is to imagine a pile of dirt. It has a peak somewhere, with sloped sides. If we scoop a lot of dirt away on one side, & less on the other, the pile of dirt will be lower, but the center peak will be shifted toward the side where you took away less. Now if you try this scheme on a concrete block wall, you can't "move" it by removing blocks, because there is no slope. Things get more difficult when there are 2 piles overlapped, & you want to "move" them in opposite directions. You need to dig out between them, but in so doing, you also dig out stuff from the opposing pile that is undesired. The pattern if removal must be carefully profiles to make this work. if you want more detail, look up their patent. www.freepatentsonline.com/10338286.pdf
This finally solved a mystery that's been bugging me for years. I took photos of a beautiful violet flower, but the photo looked very dark blue. I kept retaking the photo, because I couldn't figure it out. Now I know that the camera just didn't have the right sensor settings.
excellent information, I was always wondering about that!
The interesting thing about all of this is that colors are completely subjective. There's no such thing as green light, just eleoctromagnetic waves with a wavelength of 450nm which our brains interpret as green.
This becomes pretty evident when you consider that two different people don't necessarily see the same colors. For instance, small differences between the physiology of different peoples' eyes and brains will affect how they percieve color. It's really interesting to consider what impications this idea has for how we experience the world and the fact that most of what we experience is subjective. If any of that makes sense. It wasn't easy to articulate this thought.
Are you saying color is a pigment of our imagination?
@@dottyastercapasloke2739 🌈😶🌈
I thought 450 nm was blue and green about 530 lol
Well we appreciate your effort
I always think a what aliens would think when they see what we try to do on our screens. Imagine taking a picture and having your alien friend complain about the colours being weird.
We'd have to move to full spectrum rvs
Wait. Simply convincing yourself something must be right isn't a good way to do science? Shit! I've been doing it wrong all this time.
...you should cut down on your metatron mate, get some exercise!
I've thought about it and I'm convinced that convincing yourself of truths is a perfectly legitimate way to find truth.
@@stumbling Oh. Thank God! I was starting to get worried that I might have to reevaluate everything and start questioning god's existence, essential oils, my anti-vax positions, and the flat earth. I mean, how else would anyone come to those conclusions if other than by simply convincing yourself that it were true?
This is the problem of having little information (as opposed to none or much). You start filling the gaps with your own rationalizations.
@@EggBastion i think i understand this reference
steve, i love what kind of sponsors you use for you videos. I already bought nord VPN thanks you you and i think i'll get dashlane too. Your vids are awesome. Keep doing them for as long as it pleases you!
Hey not to disappoint you, but check out tom Scott's video about VPN
Steve Mould is an excellent science educator and charming CZcams presenter who has acquired a cult following over time due to his practical and informative no-nonsense approach in relation to all things scientific.
He presents the facts in a straightforward manner relatable to his young inquisitive audience and old alike. Whether deliberate or seemingly so, Steve Mould captivates his viewers to the last minute with his friendly gaze and ostensibly one-to-one approach, which gives the impression that he is directly communicating with a single guest at his premises, as he delves into the subject at hand.
At the end of Mould's presentation the viewer is left mesmerised with the abundance of knowledge they have acquired just by being attentive to the presentation. In this episode, Steve discusses how the colour violet may not be detected by some digital cameras due to the constraints of various anomalies associated with the visible light spectrum interacting with the devices as well as the reason rainbows cannot be adequately captured on digital equipment. ☝️🤓🤚 👀
I'm colorblind and I just ordered enchroma colorblind glasses after understanding how they work. I think it would make a great video.
For those wondering, they are actually reducing the spectrum of color entering your eyes by filtering the overlaping red/green frequencies making it easier for someone who is red/green colorblind to distinguish colors, thus tricking the brain into seeing purples for example (which I have never seen for now, still waiting for my glasses)
Can’t even think about the idea that I’ve never seen a colour before, hope you enjoy purple it’s a really good colour
I heard about those recently. Do that really work? I understand the concept but the idea of improving your vision by removing color is so weird. It would make a great video.
please give us a testimonial here when you get it. i've been meaning to get a pair for my father for some good decade now but they're sooooooooo expensive to import here in brazil...
@@TheEDWARDO199 well you never seen ultraviolet, microwave, radio, infrared, x-ray, gamma-rays.... but technically they're all colors...
@@GraveUypo Easy way to see UV, get one of your eyes lenses removed. EZ PZ.
Some graphic designer that had his removed created some amazing pictures to show how his UV-seeing eye saw the world and it looked super vibrant in comparison, since UV stimulates all the cones rather than just the shorter cone.
It’s because Pink Floyd copyrighted it for their album cover
I am SO happy that YT recommended this; this issue has bothered me for a very long time!
Perfect video thanks for figuring this out for me
Thanks for showing your credit card info. I used it to get a premium account on Dashlane!
My eyes have major issued focusing on Violet / Blue light. Things like Neon Signs in blue refuse to focus. Yet Items fluorescing responding to Black Light are fine.
pulesjet that’s because blue light refractions different than red light. Try to wear glasses with extra -0.5 diopter prescription and you’ll see it sharp
@@liavhe LOL, At 62 my eyes are all but CHIT. I need glasses to see far. I need Different glasses to see up close. Bifocals just don't work for me. For walking and talking I can't wear ether . NO Not going for a third set. LOL Yes, I understand the different Refraction indexes. IR and UV both reside outside of our normal. The Blue bit seems to be the worst for me it would seem.
pulesjet at 33 I experience exactly what you describe, especially at night, and my eyes are just fine. The optometrist usually set the prescription to match the red/green area, so for the blue light we are out of focus. One time I took a pair of -0.5 diopter glasses, and put them over my glasses, and suddenly all the blue neon/LEDs became sharp. You can try that too.
Fun fact, only signs that glow orange are actually NEON signs. The rest are filled with other various noble gasses that emit those colors as a reaction to an electrical charge. Blue ones would be filled with mercury.
Back in my high school days, shortly after the invention of colour, I went to see a stage play with a night scene that was lit exclusively by blue light. Couldn't make out a damned thing on stage. That's when I discovered how differently my eyes focus different wavelengths.
Steve, I think you might want to look at how camera sensors work. TBH, I would love do see you do a deep dive on this; it seems right up your alley.
They aren't laid out like screens with pixels made of sub pixels. Most color camera sensors use a Bayer filter with only allows red , green, or blue light onto pixel. The layout has twice as many green pixels to mimic the human eye. It takes some processing using a demosaicing algorithm to convert the "Bayer pattern image" into a regular image with red, green, and blue color information for each pixel. This processing and introduce some artifices.
Thanks for the video, you got me second guessing myself.
Wow! Didn't know about the secondary Red cone peak!
Thanks!
I am intrigued, do you have a citation for a study that shows more detailed spectral sensitivity of different cone cells? I don't think I ever seen a graph that would show a prominent second bump.
A cool way of thinking about it is by seeing a spectrum as a circle instead of a ribbon, the mixture of red and blue is violet, that's why there's a little bit of red overlap on the blue side. This can be applied to all spectra and is a very fascinating approach when understanding different sorts of polarity.
The Channel TechnologyConnection just made a very similar video about how sceens and cameras deal with light, he had a setup with RGB LEDs as well as true white LEDs (and showed the difference between combining RGB together and true white). But he didn't explain Violet/Magenta very well. But you did a great job with that, I don't know about that "bump" in red sensitivity!
This is really interesting: a couple of weeks ago I took a picture on my mobile phone of a beautiful rainbow, which didn’t show up very distinctly in the photo. Now I understand why, thank you!
I've heard that in Newton's time "blue" was cyan (like the sky) and "violet" was what we call blue today (Violets are blue)....
Indigo by the way was added by Newton so as to get 7 colors in total, which corresponds to the 7 musical notes.
According to this, Newton did not see purple beyond the blue, but Steve does clearly show the purple there... Can that be the red from another rainbow?
Technology connections has a similar video about using RGB lighting to light scenes
Your videos are super interesting. You should make a video about how colourblindness works
This has led me down a multiple day spiral of trying to better understand colour. I don't know why I never questioned the redness of violet and indigo before, though I have definitely felt that it was odd that colours can be expressed as a "colour wheel".
0:14 :
Recycle Bin
Passwords.txt
"Things pouring out of beakers"
Sneaky Steve :^}
1, Learned more about colors
2, Learned more about how pass managers protect
3, Proof that mistakes can lead to more learning
Best video out there
Color torches are gorgeous.
I love playing around with them.
Rainbows are mostly blue and yellow to me because I'm colorblind (or slightly green-red color-deficient) so on photos they don't look worse :P
The good news is the part you're missing (red/orange and purple) is the least visible on a "natural" rainbow anyway, because it's in front of a cyan sky (red+cyan=grey). Over a grey sky it looks more even.
@@jumpander - Assuming this is a rainbow caused by the Sun (and not a halo around an artificial light), all the "bands" will have a fixed width, as does the rainbow itself (it's a result of very specific diffraction angles). The "vividness" of different colours depends mainly on what's _behind_ the rainbow. Usually, that's a (blue / cyan) sky, hence why the red parts seem a bit less vivid (semi-transparent red over cyan = greyish).
Funny. I looked into this myself and made the same discovery two weeks ago.
I think the reason for this misconception is that almost all illustrations of how humor color perception works are missing the small red peak in the short wavelengths. When everyone is giving you wrong data, it's impossible to make the right conclusion.
Speaking of the issue with the fluorescent bulbs, you bring up a topic that is not discussed enough which is the color rendition index or CRI defined on Wikipedia as "a quantitative measure of the ability of a light source to reveal the colors of various objects faithfully in comparison with an ideal or natural light source". This is something I learned years ago in a lighting design course I took in college but many know about this issue. With the rise of LED's, I am surprised more don't discuss it as LED's were traditionally very poor at expressing color because they had a very poor CRI. As opposed to a quartz halogen blub which had very high CRI and was the reason that many stores used quartz bulbs for their lighting in the old days. Any chance you can do a video on CRI and its importance in choosing the right lighting for the task at hand?
Thanks for the great videos. Keep up the good work.
Even more fascinating is how cephalopods with W-shaped pupils are able to perceive colour even though they only have B&W receptors.
They use rapid focal adjustments to determine wavelength!
You need to use the CIE chromaticity diagram- RGB gamut is a triangle, not a straight line.
Yeah, but that's because the diagram maps the spectrum of light on a curve, and an entire side of the shape this forms is a line of 'imaginary' colours (aka purples.)
The last time I tried to take an epic picture the sky were bright glowing. The clouds were bathed in golden light and the double rainbow looked almost solid like made from glass.
On the picture were just grey clouds.
Could be a sensor issue, or could be an image processing pipeline issue, ie white balance, exposure etc. Steve's main camera lets him lock in those processing attributes to be sure it's consistent when comparing shots.
@@kaitlyn__L was just my smartphone anyways. I tried to change some stats but with no luck.
Bahahahaha! I love the opening lines! XD
Whoaaa! I can look at the overlapping torchlight spots and see either red+green or yellow. That's perception rather than seeing, as such, but it's still really weird and cool. :D I actually primarily see red+green because the spots were moving (I think), but the perception persists even when the video is paused. I have to make a conscious effort to mentally refocus to see the overlap as yellow.
Really weird that the white LEDs would be better than the white CF bulbs. They're basically the same technology: phosphors activated by UV light.
Amazing channel you have created
You made another mistake -- this can be the subject of an episode itself! Look at Newton's folio of the spectrum in _Optics_ . Due to translation issues and changes to the language over centuries, what he labeled as Indigo is what we call Blue; what he labeled as blue is what we now know as Cyan. You crammed "I" into a place where it was both crowded and not showing any color difference, which should be suspicious -- they should be uniformly spaced. Also, you used the "correct" labels when describing what you saw in the spectroscope.
Also, cameras don't have subpixels. They have a Bayer mask.
For your lights: you would need to buy CF bulbs from a place like B&H, made for photography; as you noticed, the common cheap home bulbs are not good at color rendering.
People make mistakes and/or their explanations are incomplete as evidenced by the fact that not all cameras use Bayer arrays.
This topic is so wide, that it is impossible to have it all at once..
You can't just say camera chips use Bayer mask. It's like saying all cars runs on gas.
There are masks, there are subpixels, there are transparent pixels and so on
A mention of the CRI rating of the bulb would be in order. The color rendition index. Light bulbs are rated for how well they show color.
Nice! Never heard of the second red sensitivity bump. To me it was always described as the colorwheel. (?) We really don't have a spectrum of colors but only 3 signals. So a blue and red signals give magenta, doesn't matter that this is not a "real" color, it's just our way of interpreting the signals.
the charm in a beautiful mistake! ( this is very much science man!! ) thank youuuuuu!!!
One of the most interesting videos ever. Congratulations.
There's still a problem with using the red subpixels to get violet:
Let's say you have a violet wavelength W, that stimulates S, M and L cones by a factor of Ws, Wm, and Wl.
You can get a compound light L from adding blue and red light that will produce Ls = Ws and Ll = Wl, so it will look close to the original color. But Lm won't be the same as Wm.
There's a big part of the visible colour spectrum that can't be reproduced by three primary color mixing, be them additive or subtractive. How big and on what distribution depends on how you choose your primary colors. With more "primaries", you'd of course get better coverage.
This is limited to standard cone cells and light wavelengths, but then there are many other complications:
Cone cell sensitivity, density, and even pigments vary from person to person, so the same mix of lights might look different to different people.
And there's something one cant's stress enough: colours are a sensation, not a physical property. Observing conditions, individuals, and other factors affect the colors perceived even if the wavelengths don't change. I blame physicists and teachers for this confusion.
3:18 lol
I was waiting for something... XD
Here I am listening to this video nodding at all the information I already know leading up to the rainbows.
When I look up momentarily I'm looking at the Grinch.
It's those little details that make me appreciate Steve beyond just the information he presents.
Wow, this is amazing and fascinating! 👍🏻😀
Love your videos. Gentle British humour and a relaxed presentation. It's like drinking a really nice cup of hot chocolate, but far more interesting.
Keep it up. Thank you!
“I thought I was wrong, but as it turns out, I was mistaken.
No one talks how at 0:40 the video wasn't fully made in Premiere Pro, now that's not a bad thing, I really appreciate all the effort you and your team puts in for these videos.
at 10:46 here's how you can clearly see how green a fluorescent bulb is: pick two rooms with windows. Light one with fluorescent bulbs and the other with incandescent. From outside, at night in my case, one window appeared quite orange, and the other quite green, though they were all painted the same off-white. I think that the brightness of such lights, when in that environment, causes our eyes to do an auto color correct and perceive it as white. But seeing these windows from outside gives us more perspective to compare them, and we notice the colors.
The same effect is apparent with our ears at loud concerts. Even if the singer is beyond being able to perform as they once did, setting the volume level to something that overwhelms our perception makes them sound fantastic. Listening later to a recording of that concert reveals the glaring flaws that the high volume had hidden during the show.
I want to learn more about that second bump in the red cones, where should I look for this info?
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@Samuel Martins Try looking up the color matching functions
Also how far into the near UV do the red and blue cones extend (after cataract surgery to remove the lens)?
Was it an experiment at 13:40? Not many people comment about you showing ”your” credit card number, which means that people probably don’t watch the part “This video was sponsored...”
I hope so.. the address is fake unless he lives in paramount building
That is probably a video clip provided by the sponsor themselves.
He also shows a few Gmail email addresses at 12:25 and at 12:26, probably not intentionally.
Yeah, it's a sponsor video clip haha.
Don't be silly, that's Robert Stewart's credit card number, from Broadway New York.
Our beloved CZcamsr is called Steve... _unless....._
To check your lights without a spectroscope, just use a CD. A radio engineer taught me that. The fine tracks on a CD act as a diffraction grate to split the spectrum the same way as a spectroscope. Try it on all your lights, especially on old fluro lights, it really does work!
Beautiful, just beautiful. Thanks )
My goodness! I was wrong once myself, I know what it feels like 😁
Coming up next the moon pictures look terrible with a digital camera
It's basically the brightness sensor which can only be one of three options usually, that can't adjust for a really bright spot in the middle, which makes it harder to focus and then even if you get your exposure down to see the details, it probably won't be focused, that with stability, specially with zoom, worst yet digital zoom(when your camera stops turning the lenses and making that zoom noise) gives you terrible moon pictures
@@Ewr42 huh, I got good moon pics with low exposure, long shutter time, and a tripod. Maximum optical zoom, later cropped the photo much more on the computer. Like ten years ago. On a point and shoot (albeit one with a bigger lens and probably bigger sensor than its contemporaries. The RX100 line easily matches or exceeds the camera I took blood moon pics with ten years ago) Agree it's basically impossible on a phone though.
@@kaitlyn__L most cameras with manual focus can actually take a decent photo if you're patient to figure out the exact exposure and shutter time, but it's near impossible with autofocus, and in my experience you need a good lens or binoculars/telescope to get a good photo from a phone/cheap camera
@@Ewr42 yeah, it wasn't exactly a cheap camera. It was like a mid range point and shoot. The lens was almost DSLR-bundled-lens sized. It didn't collapse like most point and shoots, just had a cap. It was a smaller res sensor than a £100 cheaper compact point and shoot from the same manufacturer, but I suspect it was a larger sensor as well, not just larger pixels in the same size. I actually don't remember if it strictly had manual focus, or if I just turned the exposure down enough that the edge detection could see the moon's craters. The sky was really dark in those pics. But the orange of the moon came out really well. Either way, that camera did low light waaay better than the more compact camera it had replaced. Whether it's just from a bigger lens, or also a bigger sensor.
7:08: No, if you take out the word "experience", you are right (that's the version that is usally told: you can't recreate violet). But the very same thing is true for all other wavelengths except the three specific wavelengths that the screen can generate.
Could you explain the following effect:
When you look into a bright light source (sun or lamp) for a short moment and then look away and close your eyes you see the shape of the light source in green, cyan or blue.
Does this have to do with shortly but not permanently damaged cones?
And how does only the intensity of light play a roll in the effect or also the wavelength?