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By on March 5, 2008, with 28 Comments

Do you remember one of our first posts, and probably the most famous optical illusion of all time? Back then we called it “Colored Squares Illusion“, not knowing true history behind it. Investigating a little, I found out that it was originally called “Checkershadow Illusion” and that this famous optical illusions was created way back in 1995 by Edward H. Adelson, who is working as Professor of Vision Science on MIT University. Today I bring you new version of the same effect, which looks more real-life, even though it was probably digitally created as well. In short: color of the A square on this chess board exactly matches color of the square B. Use Adobe Photoshop (or any other image editing tool) to prove this yourself! What is your opinion on this? Because of the color depth, it’s difficult to follow the directions given to prove the illusion, so I added another simple animation which shows you what happens when you reverse colors. An animated .gif has less color depth, and same letters are used for both examples. The letters, the orb and it’s shadow are the only elements which don’t reverse colors.

  • Blah

    And as most people have noticed by now, this is a chess board, not a checkers board. But I like this illusion better than the other illusions similar to this one since it is in a “real life” setting, not a fake one.

  • mike

    i like it, but its an “a” and a “b”, not “a” and “a” like you have :P

  • Anonymous

    i dont get it….

  • Jeremy

    i tried both in photoshop, but only the one with the green cylinder works. the “a” and “b” on the chess board do not match!

    • MM

      the green cylinder is an illusion featured once in DiscoveryBox. It works for me too

  • MadTurki

    Actually Blah, it is a checkers baord… someone accidentally stuck chess pieces on it ;)

  • Spare Head 3

    I wonder if anyone noticed that the ONLY chess piece that can move on that chessboard is one of the Knights?

    When setting up a chessboard, the rule I always remembered was “queen on color”; which meant that the white queen started on a white square and the black queen started on a black square.

    In the image, the pieces are set up on the wrong sides of the board- which means all the pawns have just one square to advance to before being “queened” (the white pawns are advancing “south” and the black pawns are advancing “north”), but they are blocked.

    As the only chess pieces that can “jump” over others is the Knight, that’s currently the only chess piece that can move.

  • Trey

    problem is what you say is not true i did check it in photoshop and the colors do not match so something is wrong you tell me

  • Anonymous

    mmmh sorry but photoshop says that they are different :p

  • Anonymous

    Photoshop is wrong. The illusion is correct.

    • MM

      yeah, I tried it with paint too but the big fat A and B is messing it up!!! suggestion: DONT MAKE THE A AND B!!!

  • Brian

    In Corel Photopaint there was a very slight variation between the two squares depending on exactly what pixel you were on, but if you copy a little bit of the A square and paste it onto the B square you’ll see that it really is the same color, it blends right in.

  • Anonymous

    I’ve cut it up and put it back together here:


    The illusion is correct!

  • Anonymous

    …just get the queens on the right color!

  • Dr. Evil

    Soooooooo.. i might be hopelessly wrong, but it the square with the B is the same shade as the A square, then the squares adjacent to the B should be of a darker shade than all of the other shades… but since those squares, particularly the 4 dark adjacent squares appear to be of same shade to square A, then this should in theory be a multi-illusioned illusion. same mechanism, but still. baffling stuff.

    again, i might be wrong… or psychotic. so shoot me.

  • Répondez

    OK, the board is the correct way round but the queens are definitely wrong for chess but more importantly there is no illusion. An illusion needs to be an illusion when viewed naturally not when an artifical filter of some software or whatever is used to confuse the issue. I’ve not tried it in Photoshop or any other software for that is artificial. If it needs software to show the illusion who is to say that the software is not the illusion and the diagram is correct?!!


  • Anonymous

    ‘A’ and ‘B’ are not the same: if you do a simple walk-through from square to square, ‘same’, ‘different’, ‘same’, ‘different’, you’ll see that you land on ‘different’ when you get to ‘B’…

    Sorry, but ‘B’ should have been placed on any one of its adjacent squares…

  • -IAn

    But square and and square be are inverse. How can they be the same shade?

  • Reade

    Anonymous, the whole point of the illusion is that even though ‘A’ is a black square and ‘B’ is a white square, they are still the same colour. Cut and paste in paint.

  • Anonymous

    Tu pinche pagina apesta…

  • uvalntine

    I love this illusion. What a classic

  • Dandelion

    I found another way to proof that this illusion is correct.
    Take a piece of paper. (not to thin) Place it in front of the picture on your screan and draw a circle around the A and the B.
    Take small scissors and cut two holes on those places.
    Place the piece of paper in front of the picture on your screan again, and you will see the background colour of the A and the B are exactly alike.

  • Anonymous

    I think the best thing about this illusion is that it is so good that even when explained, several people fail to see what is happening. btw, photoshop isn’t to see the illusion, it’s to see the truth, that square A and B are the same shade.

  • Anonymous

    Pretty darn cool. I did have to cut/paste the squares side by side before I could believe it. BELIEVE IT!

  • David

    Maybe the illusion is wrong. But the one and only sure thing is the illusionist didn´t know how to play chess

  • Jeremiah K Garrett

    I opened it in Photoshop, cut and pasted the squares. Even immediately side-by-side they do not look anywhere near similar.

    If you take color selector, they are both similar colors, but not the same. If you are using web based colors only, they will show up to be the exact same. Whoever created this was using an outdated color wheel it seems.

    However, although it can be “disproven” that they are not the same, the illusion still is ingenious. Most likely back in 2008 when this was written, Photoshop wouldn’t have been able to tell the difference.

  • joseamd


  • anonyMOUSE

    i SO dont get this!! it just looks like a chess board wif a shadow over it! D; plz help!!!