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An optical illusion. Squares A and B are the same color.

8724. JJBiener - 12/10/2008 5:41:01 AM

Wiz - Please explain how A and B are the same color. B is in shadow and appears lighter in color than A which is not in shadow. What kind of optical illusion can do this?

8725. TheWizardOfWhimsy - 12/10/2008 4:50:55 PM

The optical illusion comes about through what is called simultaneous contrast of light and dark. (The light or dark, some times termed brightness, is called "value.") So you need to see it in terms of "value" not "color." The cast shadow from the green cylinder darkens all of the squares and the darker squares adjacent to "B" make it seem lighter--however it is the exact same value as "A" but because "A" is adjacent to lighter squares and the white background, "A" seems much lighter by contrast.

Here is a less confusing example that uses the same contrast principle. Note how the values change on the dots when you look at it directly and indirectly. The cones in you eyes are fooled because they work by means of contrasting light.



This one uses color and both center squares are the exact same value, but note how they appear darker or lighter because of the adjacent color field that surrounds them.

8727. anomie - 12/17/2008 5:40:15 PM

Wiz, I did not believe they were the same shade. I would have bet 10 dollars against it. Just for kicks, I copied and pasted a bit of each square in PS and compared the shades. I would have lost 10 dollars.

8728. TheWizardOfWhimsy - 12/17/2008 6:51:20 PM

It makes you wonder about the many illusions in existence that we never question.

As a wise man once said, anomie:

Life is a journey from the illusions of certainty to the certainty of illusions.

8729. anomie - 12/17/2008 7:04:43 PM

Indeed, the older I get, the less I know, and the wiser I am for it. For instance, ten dollars wasn't much to wager. Ha!

8730. David Ehrenstein - 12/25/2008 9:16:35 PM

Latest FaBlog: A Jewish Tailor's Son

8731. TheWizardOfWhimsy - 12/25/2008 10:43:50 PM

A good ethical man!

8732. David Ehrenstein - 12/25/2008 11:01:38 PM

Indeed. I'm sorry there aren't more clips from The Servant on You Tube. Pinter appears in the famous restaurant scene and his line deliver is the epitome of razor-sharp elegant wit.

8733. wonkers2 - 12/26/2008 12:12:43 AM

R.I.P. Eartha Kitt

8734. wonkers2 - 12/26/2008 12:14:09 AM

8735. David Ehrenstein - 12/26/2008 12:58:35 AM

Orson Welles called her "The most xciting woman in the world."

8736. David Ehrenstein - 12/26/2008 3:41:57 AM

Here's a clip of her in All By Myself -- a marvelous documentary portrait by Christian Blackwood made a number of years back.

8737. alistairconnor - 12/26/2008 10:11:11 AM

Harold Pinter is dead

A presence who had accompanied me throughout my adult life.
His Nobel acceptance speech from 2005 bears re-reading.

8738. David Ehrenstein - 12/26/2008 11:54:40 PM

Lates tFaBlog: Fait Diver -- Darkness at the Edge of Bruce.

8739. wonkers2 - 12/31/2008 6:26:00 AM

Somerset Clearance Portraits

8740. David Ehrenstein - 1/1/2009 4:45:16 PM

JERO on Kohaku2008

8741. wonkers2 - 1/1/2009 6:21:14 PM

Nice video. Interesting story. Jero Wiki

8742. David Ehrenstein - 1/1/2009 8:57:17 PM

MORE on Jero.

8743. wonkers2 - 1/2/2009 5:40:23 PM

The country would benefit if there were more "blended families."

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