Excellent...and very interesting! Thank you for posting!

I've seen this multiple times before; it still breaks my brain every time. So much of our conscious reality is just not quite what it seems to be. Love this!

@DrAndrewSteele

3 жыл бұрын

That is EXACTLY how is makes me feel. Deliciously unsettling! And thanks!

I might be wrong, but this illusion seems to be due to an "afterimage" produced by our vision , rather than chromatic adaptation. Afterimages are known to be of a color opposite to the color seen, i.e. if one look at a bright orange patch and then look away, one will slightly perceive for a bit the same patch, but blueish. Kinda similar to the color reversal in this illusion. Otherwise, this is cool, never seen before!

@DrAndrewSteele

3 жыл бұрын

I'm not an expert on vision, but this paper makes it sound like these are much the same effect? onlinelibrary.wiley.com/doi/abs/10.1002/col.22207 If you (or anyone else!) knows better very happy to stand corrected. And thanks!

@user-rf5le6ul9m

3 жыл бұрын

​@@DrAndrewSteele If Im not mistake, this effect is not related to the brain, but to the retina. I don't know what it is called in English. I would translate (from my language) this term as "consistent color contrast" as opposed to "simultaneous color contrast". There is also a term like "Retinal Fatigue". www.xrite.com/blog/color-perception-part-3 So we don't have to worry about a broken brain ;-) It seems that this effect is due to a decrease in the amount of photopsin in the cones during prolonged exposure to light. In a certain way, this is due to the color constancy.

@Francois_Dupont

Жыл бұрын

@@user-rf5le6ul9m that is what i was also thinking. it "burns" the sensitivity in the eye to certain color. it is like a self adjusting system. if you are in a red tent, and everything is tinted red, your eyes will "burn" the red receptor so the color red is less important. it is like muscle fatigue, but with the different color receptor.

This was awesome Andrew! I thought I knew what it would entail based on the little preview on Instagram, rods and cones and whatnot, but this was much more interesting and so beautiful to look at, like your other videos. Such a pretty place in gorgeous light.

@DrAndrewSteele

3 жыл бұрын

Thanks dude! Interesting and beautiful is what I aspire to :)

Highly underrated channel!!

Thanks, I found this channel! London in infrared light, radio telescope and optical illusions - all that I love the most

I notice that if I _don't_ look at the dot once the image goes grayscale, there's no color effect -- until I look back at the dot. When misaligned, I can see a faint haze of afterimage, but it doesn't really "interact" with the image information. Once I look back at the dot, the color snaps into place. I think this means there's something beyond just the afterimage effect -- perhaps there's also a top-down process of what we expect to see.

Excellent! I made my own images with circles and colors... for example I made a row with three red circles, and underneath I made a second row with three cyan circles... when I changed the first image for the second one (it is the same but in white), my brain thought the colors were reversed

Great video, Dr. Steele! Brilliantly explained, as always. You are my son's (MonkeyFish09) hero... thank you for your kindness and for sharing your love of science and engineering with him! 😊

@DrAndrewSteele

3 жыл бұрын

Thank you! And very happy to share my excitement. :) I still remember writing a letter to UK astronomer Patrick Moore when I was about his age and how excited I was to get a reply!

What's also interesting is that if I get back to staring at the black dot even after I saw that the image was black&white I begin to see the colours again. Not as saturated as the first time, but still.

@DrAndrewSteele

3 жыл бұрын

Me too! I don't know exactly what causes that effect. My total guess is that maybe the brain is more tolerant of the nonexistent colours if they line up with objects that could be that colour in reality…

Excellent video! So clearly explained, high quality. I love it, your channel deserves more views

@DrAndrewSteele

3 жыл бұрын

Thank you!

I knew about that illusion for quite some time, but in the last example (with explanation), I noticed an interesting thing, which makes your explanation a bit incomplete or even not entirely correct. I stared at the dot whole time, and then it switched to b/w image the colors were much more vivid than on previous runs. So vivid, in fact, that I moved my gaze almost immediately, to check if is not a trick. It wasn't. I stare at the dot again and saw the colors but much fainter this time. And I did this again and saw the colors for the third time, really faintly. And then they have gone completely. To me, it looks like there's more than just brain adapting to change in lightning. I guess the oversaturation and depletions of receptors in the retina play a major role here. You basically burn a negatively-colored afterimage on your retina, and your receptors need time to recover. Normally brain just filters out that afterimage and smooth out colors across your field of view, but here just you reinforce that afterimage with a pretty strong signal. That's why it requires such perfect alignment. ...but it's just a guess. And I did this in a pretty dark room, that probably enhance the effect.

@laierr

3 жыл бұрын

And I guess it also explains blue/orange example, as you oversaturate your cones, and they just react less intensely to those colors, as there are less red and blue receptors available to kick in, after the change of the scenery.

@laierr

3 жыл бұрын

Oh, damn, now I'm hooked up on that. I guess I know what I'm going to research tonight. Thank you for a fascinating video!

@danc1873

3 жыл бұрын

Thanks for writing it down, I was about to argue precisely on these terms. There's this old belief that we see colors in a bw image after being presented a negative image because etc etc BUT it's obviously a mere negative of what saturated our cones for a while. The funny side of this is that even photographers, which for decades worked in camera oscura, seem not to catch what's going on here. Moreover, if there were really a constant, independent white-balancing of each cone (what??), it would mean that in a few seconds while staring at a painting, we would see its colors evaporate, which doesn't happen. Otherwise, there wouldn't be any needs for museum curators of putting those comfortable sofas in front of art masterpieces

@DrAndrewSteele

3 жыл бұрын

Haha, what a funny and terrifying idea that everything we looked at for any length of time would slowly desaturate in colour and vanish! I'm not an expert on this by any means so happy to stand corrected, but this paper argues that the effect is mainly in the brains rather than the cones: www.sciencedirect.com/science/article/pii/S004269890000050X And I think this paper suggests that 'afterimages' are much the same kind of effect as chromatic adaptation: onlinelibrary.wiley.com/doi/abs/10.1002/col.22207 (Just intuitively, and again as a non-expert, I find it hard to imagine how you'd draw a hard line between these two phenomena!) Really interesting though, and gets very knotty very fast from what I found when reading about this… 'Eyes and brain together' was my attempt to gloss over all of this without committing myself to anything. :)

@laierr

3 жыл бұрын

@@DrAndrewSteele I'm not an expert either, I'm just a colorblind guy who went into the rabbit hole of color perception once, and still see no bottom of it. Well, first of all, obviously, we do not preserve raw output straight from the retina. It's more of a composite and processed image, stitched from multiple samples, filtered, normalized, denoised, and so on. So there's no hard line between eyes and brain, as a raw sensor data is simply inaccessible to us. Yet, there are technics to glitch out that post-processing, and that's how most of the optical illusions work. Secondly, light receptors do need some time to relax after firing. Normally it's not a problem, as we do not stare at one point for any significant amount of time. We constantly do micro-movements with our eyes. So sensors deplete and recharge more or less evenly across your field of view. But yeah, the second option I see is that it really has to do with residual excitation in the visual cortex. And, probably, both things play the role here. But the thing that trips me off is that you need to use bright complimentary colors and stare at the spot for a long time. So, my thinking goes that you create that 'depletion mask' of complementary colors, in the retina and, giving the fact that we look at it on the RGB monitors, "normal colors" signal (which is there, look at the subpixels) became relatively stronger and we perceive that image as color one. But as soon as it not aligned perfectly, "depletion mask" got filtered out as noise.

Very well done video on an amazing subject, perfect work, thank you!

If you have ever worn tinted glasses, you will know that when taking them off after some time, everything looks tinted the opposite colour for a few minutes. This is the same effect. For example when using Orange tinted skiing goggles, everything looks blue when removing them.

Wow! That's amazing information! Great delivery too!

This is amazing! Bravo!

So cool! I've noticed similar effect wth ski goggles before: if they have a red tint, once you put them on everything looks reddish for a while, but after a couple of minutes everything looks as usual. Then once you take them off, everything looks blueish. Nice to see this effect maxed out and explained!

@DrAndrewSteele

3 жыл бұрын

I've noticed that too with the yellow glasses I sometimes wear for cycling!

This was the most beautiful example of straight forward, clear science communication I have ever seen

@DrAndrewSteele

3 жыл бұрын

Thanks so much Tom! :D

Very interesting! Excellent!!

Super video! Big LIKE and thanks for sharing.

@DrAndrewSteele

2 жыл бұрын

Thank you :D

Building three dimensionality from stereo pairs is my favourite - but done with naked eye, without lenses. That is a real marvel.

This is brilliant!

This was amazing will the trick only work for a small black dot or would it also work if it were for a person wearing all black apparel?

@DrAndrewSteele

3 жыл бұрын

It works with anything that keeps you staring at the same spot and it doesn't need to be black, so feel free to be creative!

Agradables e interesantes ejemplos. Nice and interesting examples.

This is really interesting! My brain is actually breaking. By the way i dont want to make you rush your video making, but when are you making another astronomy video?

@DrAndrewSteele

3 жыл бұрын

Thanks! And good question! I've got a few lined up but it might not be for a month or two as I've ordered a low light camera which I'm hoping to put to use filming some actual live astro stuff! So watch this space, but you might have to put up with a bit of other science in between. :)

@subagaming2075

3 жыл бұрын

Thats great! I can wait :D

Very interesting and cool illusion. However, I wouldn't agree that this is an example of 'Colour Constancy', which is a phenomenon that occurs in the brain, and explains why bananas generally look yellow in the face of changing light condition. Rather, this illusion is due to the combined effects of photoreceptor saturation and colour opponency, both of which occur within the eye itself, at the level of the retina.

Hi Andrew. Do you ever fool around with colored shadows. I've seen them but I'm still suspicious. Are the shadows really colored or is that just how we percieve them due to the collored background?

Knew that trick before but always love it.

Please tell bro how did you make these illusions😭😭😭

what do u use to change the color?

@DrAndrewSteele

2 жыл бұрын

You can do it in any photo editing app by altering the hue/saturation sliders to rotate the hue by 180° :)

Interesting, thanks. The optical illusion(s) didn't really work with me, though. I'm fairly sure it's because of my colour-sight. I am a partial dichromat (weakness in red-green spectrum). My interpretation of colours in this spectrum depend a great deal on the lightning available. I have excellent night-vision, but distinguishing certain colours with limited light is nigh impossible.

@DrAndrewSteele

3 жыл бұрын

Sorry to hear it didn't work, but interesting… In another comment, @laierr who is also colourblind can see it! kzread.info/dash/bejne/g39hm8ObmKrLqLQ.html&lc=UgyM6cmoBZOhEaZymqh4AaABAg I wonder if it might work for you with something that very strongly stimulated the 'yellow' cones and the 'blue' ones and had slightly less subtle colour information in the red/green.

Very cool!

Very interesting, thanks for sharing!

@DrAndrewSteele

3 жыл бұрын

You're welcome!

Would that mean that the brain also reduces the saturation of light sources, pushing them towards white? e.g. a blue light source might be classed as under blue light, so the brain would attempt to compensate for those lighting conditions by making it appear less blue.

@DrAndrewSteele

3 жыл бұрын

I think so, yes! I think at least some of the processing is done in the eye itself, but where eye finishes and brain starts is all a bit academic anyway… :)

That's just amazing!

Great video mate :) auto brain balance perfectly presented

@DrAndrewSteele

3 жыл бұрын

Thank you! :)

I used to pull this trick on my 5th grade students. I constructed an American flag with black stars and orange background and black and green stripes. I would have them stare at it for a minute, then look at the blank white board. They were so impressed seeing the flag in its true colors.

@palestar828

3 жыл бұрын

So it's this really real? Like he didn't just edit the video to make this happen?

@kenttm42

3 жыл бұрын

@@palestar828 try it. Stare at a colored paper for at least 30 seconds, then look away at a blank wall (preferably white) and in a moment you will "see" a rectangle of the opposite color. Your eyes become fatigued by the monochrome overload and compensate by imaging the opposite.

Whats even more crazy is that if you keep one eye closed while looking at the black dot, after it changes 1 eye will see colour and the other eye if you swap will see black and white! So the brain must be processing the image from each eye independently then?! I wonder how much further these crazy illusions could be taken if you were to play around with which eye is seeing what?!

@DrAndrewSteele

Жыл бұрын

Haha I’d never even thought of trying that! Amazing!!

It was so awesome. It mean that our brain often lies to us. I guess what are the other mysteries that our brains can do.

So good

It's awesome 😍❤️

That wus so coooool :o It’s so cooool

DIDN'T work on (for) me! Once he turned the first image into black and white it remained so until he turned it back into color. Also the paper on the left remained blue and on the right orange. Finally, the dress always looked blue and black (it's REAL and TRUE colors) to me, not white and gold (it's IMAGINED by MOST people colors).

Tired Eyes make fun colours! Is it the brain or photopsin depletion?

@DrAndrewSteele

3 жыл бұрын

That's basically the whole video in five words!

@DrAndrewSteele

3 жыл бұрын

Just saw your edit! This isn't my expertise so if anyone knows better please chime in, but this paper seems to suggest it's largely brain-based www.sciencedirect.com/science/article/pii/S004269890000050X

such a lovely channel

@DrAndrewSteele

3 жыл бұрын

Thanks :)

Here before this goes viral. Awesome video!

@DrAndrewSteele

3 жыл бұрын

Thank you! And I hope your prediction is correct :)

You're my favourite KZreadr ❤️

@DrAndrewSteele

2 жыл бұрын

Thank you!

any way how i can make the same pictures from my own photos?

@DrAndrewSteele

3 жыл бұрын

Yes! Open it in a photo editing program, use hue and saturation to change the hue by 180 degrees and turn the saturation right up, and then make a black and white version too. Then make an animated GIF or video, and you're done!

@user-sw4tu8qj5f

3 жыл бұрын

@@DrAndrewSteele awesome! thank YOU

@dustinrabin

3 жыл бұрын

@@DrAndrewSteele hi, Andrew! I've tried several times and it works BUT none of them are as stunning as your example. It looks like you added some kind of filter to make the colour image more painterly. Does this have something to do with it, and if so which filter is it in Photoshop? Thanks!

@DrAndrewSteele

3 жыл бұрын

@@dustinrabin Hi Dustin! It’s all about turning the saturation RIGHT up… I also ‘posterised’ the image, simpifying it to fewer colours, but that’s not strictly necessary…it’s just because the footage was a bit noisy and I wanted to cover the grain! The key thing is to make sure those colours are offensively bright. :) Good luck! And love to hear that people are trying this at home!

@dustinrabin

3 жыл бұрын

@@DrAndrewSteele Thanks, Andrew!

Amazing Video! do you happen to know if it has a name, suck as "the _____ effect'?

@DrAndrewSteele

2 жыл бұрын

Thanks! And I'm afraid if it does have a name like that I don't know what it is, and didn't come across it during my research for this video. Let me know if you find anything!

Okay that last time I was convinced you had thrown in an actual colour image just to screw with us, but no.

doesn't work for me

Maybe in your next video you can explain how 3 strip Technicolor got colored movies from black and white film.

Wow its realy!!

I just noticed that the flipped color pallet was used in Part 4 of JoJo's Bizarre Adventure for all the scenery.

wao, un life hack saludos desde Bolivia

@DrAndrewSteele

3 жыл бұрын

Saludos mi amigo! :)

So you basically get a pale French flag from a white paper.

@DrAndrewSteele

3 жыл бұрын

Haha you make it sound so underwhelming!

I also like this optical illusion, it's on youtube: "see The Starry Night come to life and unravel"

@DrAndrewSteele

3 жыл бұрын

That is good! Starry Night is such a good subject for that illusion.

Will this Mack me loos Color for ever !

Это как жизнь в России, вроде все красочно и красиво, а на деле мрак

@pavelgorokhov2976

3 жыл бұрын

* Рашка приплетена *

@user-wl1tm9cs5y

3 жыл бұрын

Вы тоже после статьи?

Witchcraft!!

I watched til 0:38 (and skipped ten secs from the beginning), so I saw less than 30 seconds of this 4:18 length video and I am 100% sure I missed nothing. Cool effect tho.

@DrAndrewSteele

3 жыл бұрын

Try watching the rest, you might like it!

Круто!

всё это чушь для наркоманов, но лайк поставлю

So what you're really saying is that our brains have the most awesome Auto White Balance!

@DrAndrewSteele

3 жыл бұрын

That is exactly it!

very cool short man make video good thank

what would people who have specific color blindness see on the illusion that is what I am thinking about at the moment.

@DrAndrewSteele

3 жыл бұрын

I think they'd see a similar effect? Someone with red/green colour-blindness can effectively see 'red/yellow/green' and 'blue' only, but their 'red/yellow/green' cones would dial down due to the bright orange sky just like someone with full-colour vision would. Any colour-blind viewers able to confirm?

Кто тут ещё с Медузы пришёл??

But, all what you are doing is you switch the complementary colors and stick a dot. So you are basically giving my brain the colors data to auto color a black and white photo. But if you gave me a wrong data, my brain will color the photo in a wrong way too.

My teacher made me watch this

Didn't work on me

@vinathebeagle2627

Жыл бұрын

Me neither. Once he turned the first image into black and white it remained so until he turned it back into color. Also the paper on the left remained blue and on the right orange. Finally, the dress always looked blue and black (it's REAL and TRUE colors) to me, not white and gold (it's IMAGINED by MOST people colors).

So that's why your hair matches your t-shirt? 😉

I am from argentine (argentina)🇦🇷i speak spanish no i speak english you appearend to in Google

_th_

२४INDIA BICH ISIS IMIM IAIA BSE ESE BSF EX SERVICE MAN २१

Тоже искал комментарий на русском языке?)

@PoznajuschijAbsolut

3 жыл бұрын

Да)

@SVlad_667

3 жыл бұрын

Что-то у меня эффект слабый и меньше секунды держится.

@topy2688

3 жыл бұрын

Нет

@user-nt4zm2ql2e

3 жыл бұрын

@@SVlad_667 Домики вроде как чёрно-белые, а трава всё равно зелёная

_the_

Hey man, you are the aging guy, right?

@DrAndrewSteele

3 жыл бұрын

Yes! :) (I mean, we're all ageing, but I have also written a book on it…)

This is fake. You see an ordinary cartoon. The colors change inside the video itself. You can download this video and move the slider in the player to check my words.

@DrAndrewSteele

3 жыл бұрын

No, it's real. There are no colours in the black and white photos. You can download this video and move the slider in the player to check my words.

@k39kUhmt2

3 жыл бұрын

@@DrAndrewSteele I did that before leaving the conclusion.

@k39kUhmt2

3 жыл бұрын

@@DrAndrewSteele I am sorry. My fault. It works.

@k39kUhmt2

3 жыл бұрын

@@DrAndrewSteele Good Job, nice effect!

@k39kUhmt2

3 жыл бұрын

@@DrAndrewSteele Please accept my apologies.

fake

doesn't work for me