This WILL do your head in !

[VladTepes]

Checkershadow Illusion (http://web.mit.edu/persci/people/adelson/checkershadow_illusion.html)

[DEFENDERZOOK]

once i saw the second picture......it started to make sense.......
then i tried to read the explanation.........



and now im in a padded room and wearing a fancy jacket.......

[superquag]

Dunno if all is right in mine,.....

Squint a lot and look at it... NOW it appears the same shade or Density as the A dark square, due to the shadow getting lost or integrated.
This is raw data.

When viewed normally your brain correctly interprets the square as being lighter (less Dense) than the obviously dark one, even though the light falling upon it is much less...
'
Its the Proof and Explanation that does my head in !:eek:

I'm cheating a bit.... Used to be a Photo Lithographer.

[alittlebitconcerned]

Head done in. :eek:

[Lotz-A-Landies]

I did Psychology 101 in 1985, I don't want to sit through it again in 2011! :(:(

[abaddonxi]

Try cutting a couple of holes in a piece of paper that match the squares.

[uninformed]

If you can view it on a smart phone, bring the phone up to eye level and tilt it flat/level and view across the screen. It will show you they are the same shade. It's quite simple really, the shades of the squares in the shadowed area have been darkened to give the impression of the shadow from the cylinder. As the dark is darker and also the lighter squares, it still shows up in our mind as a checker patern. It just so happens that the amount they darkened them up was equal to the difference between the non shaded dark and light squares.

[zuno555]

lol, nice try but it aint so. they are different shades. the so called "proof" bars are light at the bottom and dark at the top.

Downloaded the "proof" file, hold up paper either side of the grey proof bars, different.

This is about the same level as the stupid magic card tricks that I had to explain to people haha :)

[mojo]

They are the same colour. I tried the suggested "paint dropper" test in an image editor, and they are identicle. Bloody weird!

[Scallops]

lol, nice try but it aint so. they are different shades. the so called "proof" bars are light at the bottom and dark at the top.

Downloaded the "proof" file, hold up paper either side of the grey proof bars, different.

This is about the same level as the stupid magic card tricks that I had to explain to people haha :)

Looks like this illusion caught you twice! :D

[austastar]

Hi,
copied and pasted the 2 squares out on to the background in Photoshop.

They are the same shade.

cheers

[ramblingboy42]

If you can view it on a smart phone, bring the phone up to eye level and tilt it flat/level and view across the screen. It will show you they are the same shade. It's quite simple really, the shades of the squares in the shadowed area have been darkened to give the impression of the shadow from the cylinder. As the dark is darker and also the lighter squares, it still shows up in our mind as a checker patern. It just so happens that the amount they darkened them up was equal to the difference between the non shaded dark and light squares.

hmmm, I tried it on an old rotary dial telephone, couldnt see a thing, no matter what angle I held it at......
its doing my head in.....

[ramblingboy42]

Hi,
copied and pasted the 2 squares out on to the background in Photoshop.

They are the same shade.

cheers

I tried to do that too, but got the squares all stuck to my fingers and wiped them on my shirt...more mess.....then I knocked the jar of paste over.......its doing my head in

[Sleepy]

lol, nice try but it aint so. they are different shades. the so called "proof" bars are light at the bottom and dark at the top.

Downloaded the "proof" file, hold up paper either side of the grey proof bars, different.

This is about the same level as the stupid magic card tricks that I had to explain to people haha :)

Now this explains your funky paint job on your Disco, zuno555. You bought three cans of white paint right? :p

[Blknight.aus]

you're all missing the point.

you need to fire the guy who put the tiles down... one of the tiles should be white and the other black. All hes done is stuck a 44 gallon drum so that it casts a shadow over his cock up.

He should have paid for quality tiles and discarded any that werent right, hows it going to look tomorrow morning when the suns on the other side?

[austastar]

but got the squares all stuck to my fingers and wiped them on my shirt...more mess.

Hi,
yep, but I use a wireless mouse, so nothing in my hand actually touches the computer or screen.

cheers

[DiscoMick]

No they're not. I don't believe it. In the second pic B is still a lighter shade than A.

[VladTepes]

Told you it would do your heads in !

[Scallops]

No they're not. I don't believe it. In the second pic B is still a lighter shade than A.

:D Love it - this IS the best illusion ever! :D