Castle Optical Afterimage Illusion

Zeuzzz · 23rd June 2012, 10:02 AM

Full screen it.
http://www.youtube.com/watch?v=w6ccBwnc5KU

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I AGREE

Is this a visual effect from the colors used pre transition being implanted in our memory and transferred to the black and white image? Or is it just our brains applying the colors we usually associate with a castle to it?

Its weird that if you keep your eyes focussed on the dot the colors stay just as vivid, but as soon as you move them its instantly black and white.

Explanation and links appreciated

EHocking · 23rd June 2012, 10:11 AM

Originally Posted by Zeuzzz

Full screen it.
http://www.youtube.com/watch?v=w6ccBwnc5KU

YouTube Video This video is not hosted by the JREF. The JREF can not be held responsible for the suitability or legality of this material. By clicking the link below you agree to view content from an external website.

I AGREE

Is this a visual effect from the colors used pre transition being implanted in our memory and transferred to the black and white image?

No. It is a physiological, not psychological, effect.

Quote:

Or is it just our brains applying the colors we usually associate with a castle to it?

No. It is a physiological, not psychological, effect.

Quote:

Its weird that if you keep your eyes focussed on the dot the colors stay just as vivid, but as soon as you move them its instantly black and white.

Explanation and links appreciated

Negative afterimages.

It is a physiological, not psychological, effect

Professor Yaffle · 23rd June 2012, 10:13 AM

It's more a phenomenon of the eye than the brain.

Quote:

Negative afterimages are caused when the eye's photoreceptors, primarily those known as cone cells, adapt from the overstimulation and lose sensitivity.[1] Normally the eye deals with this problem by rapidly moving small amounts (see: microsaccade), the motion later being "filtered out" so it is not noticeable. However if the color image is large enough that the small movements are not enough to change the color under one area of the retina, those cones will eventually tire or adapt and stop responding. The rod cells can also be affected by this.[citation needed]
When the eyes are then diverted to a blank space, the adapted photoreceptors send out a weak signal and those colors remain muted. However, the surrounding cones that were not being excited by that color are still "fresh", and send out a strong signal. The signal is exactly the same as if looking at the opposite color, which is how the brain interprets it.[citation needed]

http://en.wikipedia.org/wiki/Afterimage

fuelair · 23rd June 2012, 10:16 AM

It is first seeing colors that are negative to the positive colors you are meant to perceive (you can do the same by staring intently at a picture and then closing your eyes - you will see the negative colors if you look at a positive image and vice-versa.

Sorry, I was last to see this before responses came in!!(eta)

Skeptic Ginger · 23rd June 2012, 10:41 AM

Originally Posted by Zeuzzz

....
Its weird that if you keep your eyes focussed on the dot the colors stay just as vivid, but as soon as you move them its instantly black and white.

Explanation and links appreciated

The nerve impulses which originate from every individual receptor on the retina become attenuated, so when the image changes back to black and white the receptors send a 'negative' signal so to speak. The minute you move your focus, now receptors are receiving different light frequencies and that frequency is not attenuated in that receptor.

Wiki explains it fairly well in simple terms: Afterimage

Skeptic Ginger · 23rd June 2012, 10:43 AM

Explaining the Breaking Curveball is trickier. It involves more brain (perception) and less direct nerve impulse.

For even more fun, click on "reversal" and play with the tone changer on the right.

EHocking · 23rd June 2012, 10:44 AM

Originally Posted by EHocking

...Negative afterimages.

It is a physiological, not psychological, effect

Originally Posted by Professor Yaffle

It's more a phenomenon of the eye than the brain.
http://en.wikipedia.org/wiki/Afterimage

Originally Posted by fuelair

It is first seeing colors that are negative to the positive colors you are meant to perceive (you can do the same by staring intently at a picture and then closing your eyes - you will see the negative colors if you look at a positive image and vice-versa.(eta)

Originally Posted by Skeptic Ginger

...Wiki explains it fairly well in simple terms: Afterimage

Wow. Talking about afterimages....

Skeptic Ginger · 23rd June 2012, 10:52 AM

OM-FSM, this is the weirdest one I've ever seen:

When Pretty Girls Turn Ugly: The Flashed Face Distortion Effect

Sorry, hope I'm not jacking the thread. I've never seen anything like this illusion.

Skeptic Ginger · 23rd June 2012, 10:53 AM

Originally Posted by EHocking

Wow. Talking about afterimages....

Well, you know, we get excited sometimes. Ooh, Ooh .. I know I know.

Farsight · 23rd June 2012, 11:35 AM

When I first saw the Big Spanish Castle it totally blew me away. I showed it to other guys who insisted the image was changing and I had to really work hard to get them to believe what they were seeing, or not, as the case may be.

The Pacman Illusion is a cracker too. When I saw this one I said to myself Aw, you have just got to be ******* kidding.

Weak Kitten · 23rd June 2012, 11:50 AM

I remember after images being a part of my design classes in college. Mostly they were used to explain why certain color combinations seem to "pop" more than others and why you should avoid some color combinations.

You can really cause some eyestrain by making a complex pattern out of two colors that are afterimage opposites of each-other.

steve s · 23rd June 2012, 03:10 PM

Originally Posted by Skeptic Ginger

OM-FSM, this is the weirdest one I've ever seen:

When Pretty Girls Turn Ugly: The Flashed Face Distortion Effect

Sorry, hope I'm not jacking the thread. I've never seen anything like this illusion.

Thanks for the link. I've never seen that one before.

Steve S

jj · 23rd June 2012, 06:00 PM

The explanation cited above is ok, but uses a few judgemental words that it should not.

The generation of the pigment that allows us to see in the eye is about constant. It is degraded by light,which is how we actually detect light.

Since the rate is fixed, in a low-light situation, you have a lot more pigment, and therefore 10^3 to 10^6 times the visual sensitivity you have in bright light (give or take, I'm not going to figure it all out right now).

When you stare at something, the bright parts start to deplete in pigment, the dim parts get more pigment. Then when you look away,the part of the retina that was seeing the bright areas will show a bias toward the opposite color, etc.

It's not fatigue, per se, it's part of the natural method the eye uses to adapt to the huge variation in brightness between beach and starlight.

23rd June 2012, 10:13 AM	#3
Professor Yaffle Butterbeans and Breadcrumbs Join Date: Jan 2007 Location: Emily's shop Posts: 15,351	It's more a phenomenon of the eye than the brain. Quote: Negative afterimages are caused when the eye's photoreceptors, primarily those known as cone cells, adapt from the overstimulation and lose sensitivity.[1] Normally the eye deals with this problem by rapidly moving small amounts (see: microsaccade), the motion later being "filtered out" so it is not noticeable. However if the color image is large enough that the small movements are not enough to change the color under one area of the retina, those cones will eventually tire or adapt and stop responding. The rod cells can also be affected by this.[citation needed] When the eyes are then diverted to a blank space, the adapted photoreceptors send out a weak signal and those colors remain muted. However, the surrounding cones that were not being excited by that color are still "fresh", and send out a strong signal. The signal is exactly the same as if looking at the opposite color, which is how the brain interprets it.[citation needed] http://en.wikipedia.org/wiki/Afterimage
	__________________ I think you'll find it's a little bit more complicated than that. My blog "Well I think I've made it abundantly clear in this thread I have no idea what I'm talking about..." - truethat

23rd June 2012, 10:16 AM	#4
fuelair Cythraul Enfys Join Date: May 2006 Posts: 28,945	It is first seeing colors that are negative to the positive colors you are meant to perceive (you can do the same by staring intently at a picture and then closing your eyes - you will see the negative colors if you look at a positive image and vice-versa. Sorry, I was last to see this before responses came in!!(eta)
fuelair Cythraul Enfys Join Date: May 2006 Posts: 28,945	__________________ There is no problem so great that it cannot be fixed by small explosives carefully placed. Wash this space! We fight for the Lady Babylon!!! Last edited by fuelair; 23rd June 2012 at 10:18 AM.

23rd June 2012, 10:41 AM	#5
Skeptic Ginger formerly skeptigirl Join Date: Feb 2005 Location: Shifting through paradigms Posts: 40,576	Originally Posted by Zeuzzz .... Its weird that if you keep your eyes focussed on the dot the colors stay just as vivid, but as soon as you move them its instantly black and white. Explanation and links appreciated The nerve impulses which originate from every individual receptor on the retina become attenuated, so when the image changes back to black and white the receptors send a 'negative' signal so to speak. The minute you move your focus, now receptors are receiving different light frequencies and that frequency is not attenuated in that receptor. Wiki explains it fairly well in simple terms: Afterimage
	__________________ (*Tired of continuing to hear the "Democrat Party" repeatedly I've decided to adopt the name, ~~Pubbie Party, Repubs~~ "Republics" and Republic Party in response.)

23rd June 2012, 10:43 AM	#6
Skeptic Ginger formerly skeptigirl Join Date: Feb 2005 Location: Shifting through paradigms Posts: 40,576	Explaining the Breaking Curveball is trickier. It involves more brain (perception) and less direct nerve impulse. For even more fun, click on "reversal" and play with the tone changer on the right.
	__________________ (Tired of continuing to hear the "Democrat Party" repeatedly I've decided to adopt the name, ~~Pubbie Party, Repubs~~ "Republics" and Republic Party in response.) Last edited by Skeptic Ginger; 23rd June 2012 at 10:45 AM.*

23rd June 2012, 10:44 AM	#7
EHocking Illuminator Join Date: Apr 2004 Posts: 4,409	Originally Posted by EHocking ...Negative afterimages. It is a physiological, not psychological, effect Originally Posted by Professor Yaffle It's more a phenomenon of the eye than the brain. http://en.wikipedia.org/wiki/Afterimage Originally Posted by fuelair It is first seeing colors that are negative to the positive colors you are meant to perceive (you can do the same by staring intently at a picture and then closing your eyes - you will see the negative colors if you look at a positive image and vice-versa.(eta) Originally Posted by Skeptic Ginger ...Wiki explains it fairly well in simple terms: Afterimage Wow. Talking about afterimages....
EHocking Illuminator Join Date: Apr 2004 Posts: 4,409	__________________ "A closed mouth gathers no feet" "Ignorance is a renewable resource" P.J.O'Rourke Prayer: "a sophisticated way of pleading with thunderstorms." T.Pratchett "It's all god's handiwork, there's little quality control applied", Fox26 reporter on Texas granite Forum Birdwatching Webpage

23rd June 2012, 10:52 AM	#8
Skeptic Ginger formerly skeptigirl Join Date: Feb 2005 Location: Shifting through paradigms Posts: 40,576	OM-FSM, this is the weirdest one I've ever seen: When Pretty Girls Turn Ugly: The Flashed Face Distortion Effect Sorry, hope I'm not jacking the thread. I've never seen anything like this illusion.
	__________________ (*Tired of continuing to hear the "Democrat Party" repeatedly I've decided to adopt the name, ~~Pubbie Party, Repubs~~ "Republics" and Republic Party in response.)

23rd June 2012, 10:53 AM	#9
Skeptic Ginger formerly skeptigirl Join Date: Feb 2005 Location: Shifting through paradigms Posts: 40,576	Originally Posted by EHocking Wow. Talking about afterimages.... Well, you know, we get excited sometimes. Ooh, Ooh .. I know I know.
	__________________ (*Tired of continuing to hear the "Democrat Party" repeatedly I've decided to adopt the name, ~~Pubbie Party, Repubs~~ "Republics" and Republic Party in response.)

23rd June 2012, 11:35 AM	#10
Farsight Suspended Join Date: Mar 2008 Location: Poole, UK Posts: 1,956	When I first saw the Big Spanish Castle it totally blew me away. I showed it to other guys who insisted the image was changing and I had to really work hard to get them to believe what they were seeing, or not, as the case may be. The Pacman Illusion is a cracker too. When I saw this one I said to myself Aw, you have just got to be ****** kidding*.

23rd June 2012, 11:50 AM	#11
Weak Kitten Graduate Poster Join Date: Sep 2010 Location: Lost and lonely...will you be my friend? Posts: 1,726	I remember after images being a part of my design classes in college. Mostly they were used to explain why certain color combinations seem to "pop" more than others and why you should avoid some color combinations. You can really cause some eyestrain by making a complex pattern out of two colors that are afterimage opposites of each-other.
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23rd June 2012, 03:10 PM	#12
steve s Illuminator Join Date: Feb 2006 Posts: 3,661	Originally Posted by Skeptic Ginger OM-FSM, this is the weirdest one I've ever seen: When Pretty Girls Turn Ugly: The Flashed Face Distortion Effect Sorry, hope I'm not jacking the thread. I've never seen anything like this illusion. Thanks for the link. I've never seen that one before. Steve S
steve s Illuminator Join Date: Feb 2006 Posts: 3,661	__________________ "Nature abhors a moron." -- H. L. Mencken

23rd June 2012, 06:00 PM	#13
jj grumpy old skeptic Join Date: Oct 2001 Location: Deep in the rain Posts: 18,512	The explanation cited above is ok, but uses a few judgemental words that it should not. The generation of the pigment that allows us to see in the eye is about constant. It is degraded by light,which is how we actually detect light. Since the rate is fixed, in a low-light situation, you have a lot more pigment, and therefore 10^3 to 10^6 times the visual sensitivity you have in bright light (give or take, I'm not going to figure it all out right now). When you stare at something, the bright parts start to deplete in pigment, the dim parts get more pigment. Then when you look away,the part of the retina that was seeing the bright areas will show a bias toward the opposite color, etc. It's not fatigue, per se, it's part of the natural method the eye uses to adapt to the huge variation in brightness between beach and starlight.
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