Cool Optical Illusion

[Matty]

http://www.markbarry.com/puzzles/illusion4.jpg

[ThaSaltCracka]

old.

[Matty]

Sorry, I haven't been keeping up with my subscription to Popular Optical Illusions.

[ThaSaltCracka]

someone posted it on here like 4 months ago.

[YourFoxyGrandma]

That is sweet though.

[ThaSaltCracka]

yeah it is pretty cool though.

[Leo99]

I don't get it. How come they look very different on my screen?

[ThaSaltCracka]

printscreen it and edit it in paint or something. You'll see that they are indeed the same color.

[Matty]

http://web.mit.edu/persci/people/adelson/checkershadow_description.html

[YourFoxyGrandma]

Dude, I have no idea. Maybe your monitor is broken or something. It could be that it's an

OPTICAL ILLUSION!!

(although unlikely) It's probably just your monitor.

[YourFoxyGrandma]

For the lazy folks...

http://www.rit.edu/~emr3008/illusion4corrected.jpg

[Blarg]

This is the coolest one I've ever seen!

The guy in the post right above me providing a bar linking the two squares helped a lot. I had to put my hands to the screen and block out everything but the two squares to really believe they were the same color. Very good!

[Ponks]

We talk about this kind of stuff in my psychology classes all the time. Pretty cool stuff.

Ponks

[tyfromm]

The original Shades of Grey thread with a poll (http://forumserver.twoplustwo.com/showflat.php?Cat=&Board=exchange&Number=905318&For um=,,,,,All_Forums,,,,,&Words=&Searchpage=4&Limit= 25&Main=905318)

[tyfromm]

For those who missed it a few months ago (old timers, don't give away the answer), here is a tough one:

http://img.photobucket.com/albums/v107/xdrzaiusx/optical.gif

[ThaSaltCracka]

first time I have seen this, how is this suppose to be considered tricky and/or hard?

[tyfromm]

[ QUOTE ]
first time I have seen this, how is this suppose to be considered tricky and/or hard?

[/ QUOTE ]

Some people have a hard time figuring it out, where the extra square comes from. If you have the answer, please reply in white text.

[spamuell]

I think that triangle one is pretty tricky, I asked about it in 2+2 irc the other day, I had to get someone to explain it to me, I just didn't get it at all.

[jdl22]

This too is old. Somebody posted the optical illusion above and then there were a flurry of these kind of things. Both of these are very good and I won't spoil the surprise for those that haven't seen them and don't remember.

[tyfromm]

I know it's old, I posted it months ago, but there are a lot of new posters now who haven't seen it.

The other old one I posted is this. I still can't solve this one. /images/graemlins/tongue.gif

http://www.bobandtom.com/gen3/6cover_img/optical_illusion2.jpg

[ThaSaltCracka]

to be honest with you, I misred the thing the first time I looked at it. I have no idea how there is a hole there. Please explain, perhaps via PM?

[jdl22]

This one is easy. Her hair is a metaphor for a waterfall. How do I see this? Well it's wet firstly, as is her shirt. Secondly you can see that her head is tilted in such a way so as to appear to be falling straight down as if a waterfall.

[kyro]

TSC,

I remember staring at this for at least an hour before I either finally got it, or someone gave me a hint and it dawned on me. It's pretty neat.

If tyfromm hasn't pm'd you yet, let me know and I will.

[Number4]

There's a waterfall?

[ThaSaltCracka]

yeah he told me. Pretty damn tricky, not sure how I would have gotten it if he hadn't told me.

[Lazymeatball]

Spoiler
Ok. I think I got it. The answer lies in the fact that the two triangles do not have the same slope. The red triangle has a slop of 3/8 = 3.75, while the green triangle has a slope of 2/5 = 4. This difference is farily undetectable neglecting the use of the grid pattern, so most people just assume they are the same. Do I have to explain further for full credit?

[Leo99]

I got the triangle illusion right away but even with Granny's hint I still had to print it and get scissors and cut it out. I still can't believe it.

[LondonBroil]

I would also like someone to pm me the answer to the triangle one, or at least post the reason in white.

[tyfromm]

Here is the original thread with several explanations in white text. (http://forumserver.twoplustwo.com/showthreaded.php?Cat=&Number=904539&page=&view=&sb =5&o=)

And here's another subtle optical illusion:
http://img.photobucket.com/albums/v292/myxlipsxrxtoxic/ha.gif