# Amazing Optical Illusion **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [November 3, 2003, 4:45pm UTC](https://boards.straightdope.com/t/amazing-optical-illusion/211177 "2003-11-03T16:45:10Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Bob\_Lawblaw](https://avatars.discourse-cdn.com/v4/letter/b/6f9a4e/32.png) [@Bob\_Lawblaw](https://boards.straightdope.com/u/Bob_Lawblaw)\ **Post date:** [November 3, 2003, 4:45pm UTC](https://boards.straightdope.com/t/amazing-optical-illusion/211177/1 "2003-11-03T16:45:10Z")
Saw [this](http://www.ebaumsworld.com/checkershadow.html) on the weekend and just had to share. I compared the squares in MS Paint and sure enough they are the same shade. Amazing! ---
**Author:** ![Jackknifed\_Juggernaut](https://avatars.discourse-cdn.com/v4/letter/j/9de053/32.png) [@Jackknifed\_Juggernaut](https://boards.straightdope.com/u/Jackknifed_Juggernaut)\ **Post date:** [November 3, 2003, 5:13pm UTC](https://boards.straightdope.com/t/amazing-optical-illusion/211177/2 "2003-11-03T17:13:43Z")
Wow. That is pretty amazing. But I did notice that the letters “A” and “B” are different shades. I wonder how much that strengthens the illusion. ---
**Author:** ![TaxGuy](https://avatars.discourse-cdn.com/v4/letter/t/b19c9b/32.png) [@TaxGuy](https://boards.straightdope.com/u/TaxGuy)\ **Post date:** [November 3, 2003, 6:07pm UTC](https://boards.straightdope.com/t/amazing-optical-illusion/211177/3 "2003-11-03T18:07:10Z")
Damn, that’s cool. I bet if you were to ask a million painters to paint that little still life, only like 1% would paint those two tiles the exact same shade of gray. Hmmm, you know how some people have perfect pitch? I wonder if it’s possible for some people to look at the illusion and say “Well of course they’re the same shade, nimrods? What’s the trick?” meaning that the person isn’t affected by the shades around A and B, they can simply see A and B for what they really are. Or is perfect pitch and what I’m talking about not analogous at all? ---
**Author:** ![Improv\_Geek](https://avatars.discourse-cdn.com/v4/letter/i/b3f665/32.png) [@Improv\_Geek](https://boards.straightdope.com/u/Improv_Geek)\ **Post date:** [November 3, 2003, 6:18pm UTC](https://boards.straightdope.com/t/amazing-optical-illusion/211177/4 "2003-11-03T18:18:59Z")
I remember reading an article a few years ago concerning some women who apparently have a fourth cone in their eyes. Normally we have three, and they had four. And it somehow affected their interpretation of color towards more exacting matches. I bet they could see it. I can’t but it is damn cool ---
**Author:** ![Shagnasty](https://avatars.discourse-cdn.com/v4/letter/s/9dc877/32.png) [@Shagnasty](https://boards.straightdope.com/u/Shagnasty)\ **Post date:** [November 3, 2003, 6:38pm UTC](https://boards.straightdope.com/t/amazing-optical-illusion/211177/5 "2003-11-03T18:38:57Z")
I still choose not to believe it. I won’t even waste my time with Paint because I KNOW that it isn’t true. ---
**Author:** ![Ilsa\_Lund](https://avatars.discourse-cdn.com/v4/letter/i/a6a055/32.png) [@Ilsa\_Lund](https://boards.straightdope.com/u/Ilsa_Lund)\ **Post date:** [November 3, 2003, 6:48pm UTC](https://boards.straightdope.com/t/amazing-optical-illusion/211177/6 "2003-11-03T18:48:05Z")
> [@](#): > > \*Originally posted by Shagnasty \* > \*\*I still choose not to believe it. I won’t even waste my time with Paint because I KNOW that it isn’t true. \*\* WHOOSH? ---
**Author:** ![idiotboy](https://avatars.discourse-cdn.com/v4/letter/i/b487fb/32.png) [@idiotboy](https://boards.straightdope.com/u/idiotboy)\ **Post date:** [November 3, 2003, 6:51pm UTC](https://boards.straightdope.com/t/amazing-optical-illusion/211177/7 "2003-11-03T18:51:07Z")
What? Like a fourth primary color? Like [Squant](http://www.negativland.com/squant/)?? ---
**Author:** ![Bear\_Nenno](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bear_nenno/32/3358_2.png) [@Bear\_Nenno](https://boards.straightdope.com/u/Bear_Nenno)\ **Post date:** [November 3, 2003, 7:04pm UTC](https://boards.straightdope.com/t/amazing-optical-illusion/211177/8 "2003-11-03T19:04:09Z")
I did waste my time with PAINT and I am still not convinced. I copied, pasted and then zoomed in. The tiles still appear to be different. What’s the deal? Maybe my PAINT is even confused! ---
**Author:** ![Bear\_Nenno](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bear_nenno/32/3358_2.png) [@Bear\_Nenno](https://boards.straightdope.com/u/Bear_Nenno)\ **Post date:** [November 3, 2003, 7:08pm UTC](https://boards.straightdope.com/t/amazing-optical-illusion/211177/9 "2003-11-03T19:08:50Z")
OK… I just played with the cut and paste. I pasted a piece of each square side by side in the white area. HOLY CRAP!! That’s scary. Can’t trust my eyes for anything now. ---
**Author:** ![Frank\_2](https://avatars.discourse-cdn.com/v4/letter/f/8c91f0/32.png) [@Frank\_2](https://boards.straightdope.com/u/Frank_2)\ **Post date:** [November 3, 2003, 7:13pm UTC](https://boards.straightdope.com/t/amazing-optical-illusion/211177/10 "2003-11-03T19:13:32Z")
> [@](#): > > \*Originally posted by Shagnasty \* > \*\*I still choose not to believe it. I won’t even waste my time with Paint because I KNOW that it isn’t true. \*\* [Still not convinced?](http://www.moderngroup.com/images/checkershadow.jpg) The squares are the same color: 107, 107, 107 in RGB format. ---
**Author:** ![missbunny](https://avatars.discourse-cdn.com/v4/letter/m/76d3ee/32.png) [@missbunny](https://boards.straightdope.com/u/missbunny)\ **Post date:** [November 3, 2003, 7:32pm UTC](https://boards.straightdope.com/t/amazing-optical-illusion/211177/11 "2003-11-03T19:32:11Z")
I don’t understand. They are saying that the dark gray A square is the exact same color as the light gray/white B square? Or that the letters inside are the same shade? ---
**Author:** ![Bob\_Lawblaw](https://avatars.discourse-cdn.com/v4/letter/b/6f9a4e/32.png) [@Bob\_Lawblaw](https://boards.straightdope.com/u/Bob_Lawblaw)\ **Post date:** [November 3, 2003, 7:39pm UTC](https://boards.straightdope.com/t/amazing-optical-illusion/211177/12 "2003-11-03T19:39:43Z")
The A square is the same shade as the B square. ---
**Author:** ![KidCharlemagne](https://avatars.discourse-cdn.com/v4/letter/k/ed8c4c/32.png) [@KidCharlemagne](https://boards.straightdope.com/u/KidCharlemagne)\ **Post date:** [November 3, 2003, 7:40pm UTC](https://boards.straightdope.com/t/amazing-optical-illusion/211177/13 "2003-11-03T19:40:06Z")
That’s fucked up. I agree that the A and B shading difference really strengthens the illusion. ---
**Author:** ![everton](https://avatars.discourse-cdn.com/v4/letter/e/ecb155/32.png) [@everton](https://boards.straightdope.com/u/everton)\ **Post date:** [November 3, 2003, 7:52pm UTC](https://boards.straightdope.com/t/amazing-optical-illusion/211177/14 "2003-11-03T19:52:03Z")
> [@](#): > > \*Originally posted by ronincyberpunk \* > I remember reading an article a few years ago concerning some women who apparently have a fourth cone in their eyes. Normally we have three, and they had four. And it somehow affected their interpretation of color towards more exacting matches. > > I bet they could see it. I can’t but it is damn cool In fact everybody has about [7 million cones](http://www.howstuffworks.com/eye2.htm), not three or four, but they usually contain [three different types of pigment](http://science.howstuffworks.com/eye3.htm) to enable them to specialise in detecting different ranges of the colour spectrum. In any case, the puzzle depends on a perception of tone rather than hue, so having superior colour vision might not be any help. ---
**Author:** ![Bruce\_Daddy](https://avatars.discourse-cdn.com/v4/letter/b/85f322/32.png) [@Bruce\_Daddy](https://boards.straightdope.com/u/Bruce_Daddy)\ **Post date:** [November 3, 2003, 7:55pm UTC](https://boards.straightdope.com/t/amazing-optical-illusion/211177/15 "2003-11-03T19:55:45Z")
> [@](#): > > \*Originally posted by Frank #2 \* > \*\*[Still not convinced?](http://www.moderngroup.com/images/checkershadow.jpg) The squares are the same color: 107, 107, 107 in RGB format. \*\* _That_ is equally screwed up. ---
**Author:** ![SmackFu](https://avatars.discourse-cdn.com/v4/letter/s/53a042/32.png) [@SmackFu](https://boards.straightdope.com/u/SmackFu)\ **Post date:** [November 3, 2003, 7:57pm UTC](https://boards.straightdope.com/t/amazing-optical-illusion/211177/16 "2003-11-03T19:57:29Z")
I agree, Frank’s picture is even more messed up. I would swear there is a gradient on that area connecting them. ---
**Author:** ![Herge](https://avatars.discourse-cdn.com/v4/letter/h/a183cd/32.png) [@Herge](https://boards.straightdope.com/u/Herge)\ **Post date:** [November 3, 2003, 8:13pm UTC](https://boards.straightdope.com/t/amazing-optical-illusion/211177/17 "2003-11-03T20:13:23Z")
Just shows how our eyes can deceive us. I never ever in a million years would have thought those tiles were the same colour. ---
**Author:** ![Thinks2Much](https://avatars.discourse-cdn.com/v4/letter/t/73ab20/32.png) [@Thinks2Much](https://boards.straightdope.com/u/Thinks2Much)\ **Post date:** [November 3, 2003, 8:35pm UTC](https://boards.straightdope.com/t/amazing-optical-illusion/211177/18 "2003-11-03T20:35:51Z")
I used Paint to remove the letters by pasting a copied section of the A block and that doesn’t help - if anything the difference seems greater without them. Too weird! ---
**Author:** ![criminalcatalog](https://avatars.discourse-cdn.com/v4/letter/c/e68b1a/32.png) [@criminalcatalog](https://boards.straightdope.com/u/criminalcatalog)\ **Post date:** [November 3, 2003, 8:53pm UTC](https://boards.straightdope.com/t/amazing-optical-illusion/211177/19 "2003-11-03T20:53:22Z")
bitchin’ illusion ---
**Author:** ![greck](https://avatars.discourse-cdn.com/v4/letter/g/7ab992/32.png) [@greck](https://boards.straightdope.com/u/greck)\ **Post date:** [November 3, 2003, 9:03pm UTC](https://boards.straightdope.com/t/amazing-optical-illusion/211177/20 "2003-11-03T21:03:42Z")
To me what’s amazing is the fact that our brains are so sophisticated as to understand context, and automatically adjust. Somehow we know that the square in the shadow is lighter and is made dark cause of the shadow. That our brain allows us to see the lighter square AND the shadow over it. [Next page](https://boards.straightdope.com/t/amazing-optical-illusion/211177.md?page=2)