Checkershadow: cool optical illusion

[Vay]

web.mit.edu/persci/people/adelso … .html?gray

I didn’t believe it at first. Check the proof and explanation below the picture.

[Chicken]

Wow. Just fricken wow. The pop-up with movies of others was wow too. Wow X 2.

[Rascal]

Cool stuff.

[Lord_Lucan]

Stool cuff.

[cfimages]

It says that the RGB values are 120-120-120 in both squares. But, just because I can, I discovered that this is not actually true - they are 120-120-120 in most of the square, but range between 119 and 122 in parts of the square (although both squares show the same values in the same places). So they match, but the grey is not constant over the whole square.

[twocs]

@cfimages

It says that the RGB values are 120-120-120 in both squares. But, just because I can, I discovered that this is not actually true - they are 120-120-120 in most of the square, but range between 119 and 122 in parts of the square (although both squares show the same values in the same places). So they match, but the grey is not constant over the whole square.

I don’t believe you are correct in saying that the gray is not constant over the whole square. For the squares A and B, the color does not vary at all except where the letter is printed. To do my test I used Colorzilla, a color tester available for Mozilla Firefox. You can get it at http://www.iosart.com/firefox/colorzilla/. Then you will see that the RGB values are actually constant in both of the two squares.

[cfimages]

@twocs

[quote=“cfimages”]It says that the RGB values are 120-120-120 in both squares. But, just because I can, I discovered that this is not actually true - they are 120-120-120 in most of the square, but range between 119 and 122 in parts of the square (although both squares show the same values in the same places). So they match, but the grey is not constant over the whole square.

I don’t believe you are correct in saying that the gray is not constant over the whole square. For the squares A and B, the color does not vary at all except where the letter is printed. To do my test I used Colorzilla, a color tester available for Mozilla Firefox. You can get it at http://www.iosart.com/firefox/colorzilla/. Then you will see that the RGB values are actually constant in both of the two squares.[/quote]

I opened in Photoshop and used the eyedropper tool and watched the RGB values. They changed a little. It could be because my monitors are color calibrated which ensures accuracy, whereas most people’s aren’t.