PetaPixel

Amazing Optical Illusion Shows That Our Eyes Are Horrible Light Meters

Here’s a mind-bending video in which someone created the famous checker shadow illusion in real life. The optical illusion takes advantage of the way our brains process lighting and shadows.

As with many so-called illusions, this effect really demonstrates the success rather than the failure of the visual system. The visual system is not very good at being a physical light meter, but that is not its purpose. The important task is to break the image information down into meaningful components, and thereby perceive the nature of the objects in view. [#]

Interesting huh? Our eyes aren’t very good as a light meters, since they’re easily deceived by context.

Here’s the same optical illusion as a graphic:

The squares labeled A and B are exactly the same color (use the color-dropper tool in Photoshop if you don’t believe it).

(via Gizmodo via Strobist)


 
  • http://twitter.com/jeffreyremick Jeffrey Remick

    With brightness turned all the way up:

  • Anonymous

    what was the point of that? The two squares are still the same colour…

  • http://profiles.google.com/n1ghtcr4wl N1ght Crawler

    I want to see the board in the video without the cylinder.

  • http://profiles.google.com/n1ghtcr4wl N1ght Crawler

    I want to see the board in the video without the cylinder.

  • Tsalonia

    If you look closely, the last time she moves it, you can see that the tile is translucent, allowing the color of the tile beneath it to show through. Scam!!!

  • Tsalonia

    If you look closely, the last time she moves it, you can see that the tile is translucent, allowing the color of the tile beneath it to show through. Scam!!!

  • http://twitter.com/ScottGroller Scott Groller

    You’ve been duped. It’s a manipulation.

  • cruddy

    It is not translucent moron, obviously your eyes are not the same amazing machines that this article is describing.

  • cruddy

    It is not translucent moron, obviously your eyes are not the same amazing machines that this article is describing.

  • Ilikesprite

    How is it a scam; it’s an optical illusion, for Christ’s sake.

  • Ilikesprite

    How is it a scam; it’s an optical illusion, for Christ’s sake.

  • kendon

    plus one for the board with the cylinder removed. i know this effect, and it actually does work this way, nevertheless the video looks fake.

  • kendon

    plus one for the board with the cylinder removed. i know this effect, and it actually does work this way, nevertheless the video looks fake.

  • fd

    I have to agree, the change in shade when she moves it doesn’t seem real. I know this optical Illusion and on paper it does work. So it would be much nicer to see the removal of the cylinder instead.

  • fd

    I have to agree, the change in shade when she moves it doesn’t seem real. I know this optical Illusion and on paper it does work. So it would be much nicer to see the removal of the cylinder instead.

  • http://www.facebook.com/profile.php?id=1618462537 Michael Mark

    Using the large image above and some cut up sticky notes, Cover Up all the non-A and non-B squares.  NOW… YES, they’re the same “color”.  They’re both gray.  Different Shades of gray, not at all the same in side-by-side comparison, but both gray.

    That’s not an optical illusion.  That’s a word play.

    Stupid.

  • http://www.petapixel.com Michael Zhang

    http://en.wikipedia.org/wiki/File:Same_color_illusion_proof2.png

    They’re actually exactly the same shade of gray. You can use any color checker to verify it

  • http://www.petapixel.com Michael Zhang

    http://en.wikipedia.org/wiki/File:Same_color_illusion_proof2.png

    They’re actually exactly the same shade of gray. You can use any color checker to verify it

  • http://www.petapixel.com Michael Zhang

    http://en.wikipedia.org/wiki/File:Same_color_illusion_proof2.png

    They’re actually exactly the same shade of gray. You can use any color checker to verify it

  • Paul

    If it was translucent.. you would see the lines between the squares through it. It’s not a scam.

  • geust

    I KNOW it’s fake, because my eyes can’t possibly be tricked by an optical illusion!!!1!1!!1!

    Eesh people, relax

  • Epe

    Try sticking your finger in between the squares (assuming your screen and finger are of such a size that your finger overlaps both squares slightly). You can much more easily see that they’re the same shade if you obscure the space between them. Works for both the static image and the video.

  • Arthur Vandelay

    Michael Mark, kudos to you for signing your post quite honestly: “stupid”…

  • Walter

    Agree with you Michael Z. I suspected shenanigans, so I took the image above, put it into Photoshop, cut out the B square and moved it up next to the A square. They really are EXACTLY the same shade and colour, identical in a side by side comparison. It bends your brain as you move it back and forth, giving exactly the same effect as in the video.

  • http://www.fatphotographer.net Ashley Beolens

    Optical illusions are great, can’t believe people think this is fake!!

  • James Rise

    People who believe everything their eyes show them get so upset when it is demonstrated how wrong they are. I assume that these people are suffering from the same sort of delusion as those who believe everything they read in tabloids.

  • Piet de Vries

    In reality the squares can’t possibly be of the same color. If they were, the outcome of a color picker tool would differ due to the different light conditions they’re exposed to. So it is a bit of a trick imo.

  • Rich Boakes

    Use a color picker on the original image and you’ll see that they are the same color.  The light grey square, when in shadow, is as dark as the dark grey square that is in the light, but it is surrounded by darker squares, so appears lighter.  A color picker can show this perfectly well.  In the video however, the light grey tile in shadow is moved into the light so it should become lighter, but it stays the same colour, which is not possible, so some trickery is used.

  • http://harveynick.wordpress.com/ HarveyNick

    In the video she moves the square out of the shade and its apparent shade shifts. Therefore, the apparent colour of the two squares is not actually the same in the initial configuration. The video is not a completely accurate reproduction of the optical illusion.

  • Anonymous

    I did it in PHOTOSHOP…and that worked. Unbelievable!

  • DanH

    @HarveyNick:disqus:  I agree.  The point of the optical illusion is that you take two squares of different color (one dark, one light) and light them differently (dark gets more light, light gets shadow) so that they appear to be the same apparent shade.  Our brains ignore the shade matching basically and interpret them correctly as being of different color under similar lighting conditions.  If you were to swap the two squares then the dark would get darker and the light would get lighter.  They would no appear to be the same shade. 
    The video illusion would have been more cool had the light really been fake and not making a shadow at all but the checkerboard been ‘painted’ to appear that the light had been making a shadow.  But observing the video the moving square appears to receive the edge of the shadow as it  is moved.  The ‘reveal’ in the video is not as impressive.

  • Mikko M

    It can be tested without photoshop: Just put your fingertips against and top of the image so that you can see only A and B.

    They are same color and shade. Cool. but not that surprising.

  • Jjoseph H

    If you dont believe it then this will surely do. Download the picture and cut out the two boxes and place them side by side and you will see that they are indeed the same shades of gray

  • Spareuser

    The shaded area is infact very well lit from the right (look at the shadow below her hands and arms) – the checkerboard around the moved tile is painted to make the illusion. It’s still an illusion and it is not ‘fake’ as such.

  • Adrian

    I totally understand the optical illusion.

    What I don’t understand is how does a light colored square (from the cylinder shaded area) turn into a dark square (from the area outside the cylinder shaded area).
    The square in the center of the board is “light” colored , and the square that it’s compared to (near the outside of the board) is “dark” colored.

    I would have thought that if the piece of paper in the shaded area was
    light colored, it would only be lighter outside the shaded area(since
    there’s more light hitting it), not darker.

    When she moves the piece of paper, from the center of the board, the paper is the color of the light colored square. Then she moves it to the dark square near the outside of the board, and it’s now a dark color???

    What am I missing here?

  • ihatemorons

    Hey all you skeptics. Its the same color! You can easily prove it by taking a screenshot of the video, opening the image into a Photoshop and taking a pixel sample using the eyedropper tool. Easy. And its definitive proof its the exact same color.

  • ihatemorons

    Hey all you skeptics. Its the same color! You can easily prove it by taking a screenshot of the video, opening the image into a Photoshop and taking a pixel sample using the eyedropper tool. Easy. And its definitive proof its the exact same color.

  • ihatemorons

    Hey all you skeptics. Its the same color! You can easily prove it by taking a screenshot of the video, opening the image into a Photoshop and taking a pixel sample using the eyedropper tool. Easy. And its definitive proof its the exact same color.

  • SAN

    No need for a color picker. I just copied and pasted the image in paint, cut the B tile and moved it near A, the color changed (or rather it showed the real color).

  • SAN

    No need for a color picker. I just copied and pasted the image in paint, cut the B tile and moved it near A, the color changed (or rather it showed the real color).

  • Archer

    For the non-believers: Copy the image to your desktop. Open it. Print it. Then go old-school with a pair of scissors. It’s a great way to win a bet (the one that you just lost).

  • Archer

    For the non-believers: Copy the image to your desktop. Open it. Print it. Then go old-school with a pair of scissors. It’s a great way to win a bet (the one that you just lost).

  • http://twitter.com/Soiden Sebastián Soto

    It amazes me now many people didn’t know about this optical illusion. I’ve known about it for, like, 12 years.

  • Ricky

     People are skeptical of this because it is not what the actual optical illusion as seen in the 2d drawing represents.  The purpose is to show that, when separated, and light differently, different shades actually appear to be the same.  In a 2d drawing, and an actual light meter will show they are the same shade but does that mean the paint is the same? No.  The whole purpose is to show they look different, because they are (showing the magic of our eyes) YET a light meter or photoshop will show you they are the same color.

    This video is faked, as are ALL of this users videos, he specializes in camera tricks and games.  He changed what the original illusion claimed and reversed it, saying they look different under different lighting conditions but are the same paint.  When in the history of ever has something gotten darker when put into light?  If this were true, that would mean it upper square is also the same color as the ones diagonal to it, which are clearly darker (in shade) to the movable one.

    The illusion is true (but only when the squares are separate under different lighting) the video is faked, but he has bastardized it and ends up saying, without the light, the entire board is the same color, and the light magically creates a checker board.

    The give away is the diagonal squares between them.  When it is moved up top, it is supposedly the same color as the diagonal ones (which are partially in light and partially out) notice, how the part that is in the dark is dark, and the part that is out is lighter (duh, like light behaves) but yet his magic square changes colors.

    He has faked a real illusion.  ironic.

  • Ricky

     People are skeptical of this because it is not what the actual optical illusion as seen in the 2d drawing represents.  The purpose is to show that, when separated, and light differently, different shades actually appear to be the same.  In a 2d drawing, and an actual light meter will show they are the same shade but does that mean the paint is the same? No.  The whole purpose is to show they look different, because they are (showing the magic of our eyes) YET a light meter or photoshop will show you they are the same color.

    This video is faked, as are ALL of this users videos, he specializes in camera tricks and games.  He changed what the original illusion claimed and reversed it, saying they look different under different lighting conditions but are the same paint.  When in the history of ever has something gotten darker when put into light?  If this were true, that would mean it upper square is also the same color as the ones diagonal to it, which are clearly darker (in shade) to the movable one.

    The illusion is true (but only when the squares are separate under different lighting) the video is faked, but he has bastardized it and ends up saying, without the light, the entire board is the same color, and the light magically creates a checker board.

    The give away is the diagonal squares between them.  When it is moved up top, it is supposedly the same color as the diagonal ones (which are partially in light and partially out) notice, how the part that is in the dark is dark, and the part that is out is lighter (duh, like light behaves) but yet his magic square changes colors.

    He has faked a real illusion.  ironic.

  • Ricky

     People are skeptical of this because it is not what the actual optical illusion as seen in the 2d drawing represents.  The purpose is to show that, when separated, and light differently, different shades actually appear to be the same.  In a 2d drawing, and an actual light meter will show they are the same shade but does that mean the paint is the same? No.  The whole purpose is to show they look different, because they are (showing the magic of our eyes) YET a light meter or photoshop will show you they are the same color.

    This video is faked, as are ALL of this users videos, he specializes in camera tricks and games.  He changed what the original illusion claimed and reversed it, saying they look different under different lighting conditions but are the same paint.  When in the history of ever has something gotten darker when put into light?  If this were true, that would mean it upper square is also the same color as the ones diagonal to it, which are clearly darker (in shade) to the movable one.

    The illusion is true (but only when the squares are separate under different lighting) the video is faked, but he has bastardized it and ends up saying, without the light, the entire board is the same color, and the light magically creates a checker board.

    The give away is the diagonal squares between them.  When it is moved up top, it is supposedly the same color as the diagonal ones (which are partially in light and partially out) notice, how the part that is in the dark is dark, and the part that is out is lighter (duh, like light behaves) but yet his magic square changes colors.

    He has faked a real illusion.  ironic.

  • Vikasmahalo

    Can someone tell what is the color of the surrounding four appearing-to-be-dark-grey boxes?

  • Vikasmahalo

    Can someone tell what is the color of the surrounding four appearing-to-be-dark-grey boxes?

  • Allen Forrest

     There is some confusion here, mostly semantically.  The illusion is not fake, it is well documented and OLD.  However, this video is partially demonstrating the real portion of the illusion as well as a a FAKED video trick which the uploader willingly admits.

    Understand there are three components to the visual color here:
    -actual painted color
    -color it appears to our eyes
    -color that would be read by a light meter, or photoshop color picker

       The two squares are painted differently, always were, always will be.  The original MIT illusion shows that when in shadow, the light color, when in shadow and surrounded by the dark squares becomes significantly darker.  It only claims that our eyes see them as two different colors, but they are actually not, still same paint color, the light just visually became darker as per a photoshop picker, if you screenshot it and photoshop it or print it and fold the paper you can see this is true.  Thats the ONLY thing the original illusion claims.  Our eyes still tell us that it is lighter that the outside one because it is surrounded by dark squares that got darker equally with the shadow.

       The part that has everyone is excited about and is in controversial is when the girl in the video moves the square out of the shadow and it magically gets darker (since when do things get darker when moved IN to light?).  This is faked, and the user admits this in the description on YouTube.  This is simply to show the color regardless of the light, however the video is very misleading and many people believe it actually appears that way.  This can be understood by comparing with the diagonal squares which lie in both light and shadow.

      Conclusion: the illusion is true.  this video implies a lot more which has people confused yet the poster admits is a trick.

  • Allen Forrest

     There is some confusion here, mostly semantically.  The illusion is not fake, it is well documented and OLD.  However, this video is partially demonstrating the real portion of the illusion as well as a a FAKED video trick which the uploader willingly admits.

    Understand there are three components to the visual color here:
    -actual painted color
    -color it appears to our eyes
    -color that would be read by a light meter, or photoshop color picker

       The two squares are painted differently, always were, always will be.  The original MIT illusion shows that when in shadow, the light color, when in shadow and surrounded by the dark squares becomes significantly darker.  It only claims that our eyes see them as two different colors, but they are actually not, still same paint color, the light just visually became darker as per a photoshop picker, if you screenshot it and photoshop it or print it and fold the paper you can see this is true.  Thats the ONLY thing the original illusion claims.  Our eyes still tell us that it is lighter that the outside one because it is surrounded by dark squares that got darker equally with the shadow.

       The part that has everyone is excited about and is in controversial is when the girl in the video moves the square out of the shadow and it magically gets darker (since when do things get darker when moved IN to light?).  This is faked, and the user admits this in the description on YouTube.  This is simply to show the color regardless of the light, however the video is very misleading and many people believe it actually appears that way.  This can be understood by comparing with the diagonal squares which lie in both light and shadow.

      Conclusion: the illusion is true.  this video implies a lot more which has people confused yet the poster admits is a trick.