Here's one:



Examine the squares with an RGB colour checker. They really are the exact same shade of grey!

That is too cool.

I love this kinda stuff. Like the image that looks like three bars of colour that are each going from dark to light - except that the middle bar is actually the same colour the whole way through.

That is amazing.

I'm not buying it...

Why, when I cover the green entirely, does B not appear darker?

I'm sure it has to do with how the mind processes information from the eyes (why B doesnt appear darker to you, but if you have Paint Shop Pro or Photoshop or the like, you can prove it to yourself.

Yes, I'm sure the color checker will confirm they are the same. But for an illusion that is dependent on the the green cylinder to affect how the eye views the squares, the absence of said cylinder should revert the squares to the same color.

It's still comparing with the darker squares, which also got darker due to the shadow falling across them and that lighter gray square.

It's not the green cylinder that causes the problem. It's the shadow and the persistence of the checkerboard pattern in your mind.

When I cut out two little squares and lay the paper over the checkerboard, they're still different colors.

I don't know what you're doing, John, but they just aren't different colors. Here are A and B cropped right around the letter (for the best effect, as the squares RGB value varies as it heads toward the edges).

Thanks, James

It isn't the green that throws you. The change in the surrounding squares is what really makes the difference.



Great optical!

not to mention the change in colours of the letters 'a' and 'b' - that is throwing you as well

There's a whole bunch more at this site:

http://www.echalk.co.uk/amusements/Opti ... ption.html

Obviously, the problem was in the gray matter used.

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Wow... I made it into the top 20 posters. I sure talk alot.

(or as my shop teacher used to say...)

McConnell, you have diarrhea of the mouth and constipation of the brain.

Freaky!

I think that one works much the same way as staring at a US Flag, and then looking elsewhere and seeing a flag colored green, black and orange.

Ow! My eyes! The burning!

Cool

Cool...

Time to bring the kids over and have them amazed!

Neat-o!