In the image below, are the blocks A and B the same colour and shade, or different?

(The actual blocks, not the letters)


http://homepage.powerup.com.au/~boldajis/images/optical.png

nope
i even cut them both out and i say no

no..

some optical illusion. you are probably going to say that we are wrong but i still say NO.

fairly old, they're the same colour

look at it with a hazed vision and you'll see

yeah, ive seen this before. they are the same... crazy.

what are you guys on about ?

Pull out your favourite painting program and compare the colours (with eyedrop tool or whatever).

And yes it is old, but obviously not old for everyone.

What happens if you put square A on a treadmill? http://users.bigpond.net.au/ritsuko/emoticons/plane-treadmill.gif

they are not the same colour, you can tell just by looking.

I don't know what's going on, can someone please explain this to me?

This illusion is making no sense at all, surely it can't be real.

While I cbf doing the paint thing, they certainly don't look the same to me. But I'll take your word for it.

The Paint thing confirms that they are indeed the same colour.

Now I just want to know *HOW*?

Because a brain is not a video camera that sees things for how they are, most of what you 'see' right this second comes from estimates and memory that fit in with rough visual cues, there are many many mistakes your vision system makes that can be demonstrated through these excercises.

In this case you know that the squares are meant to be black, white, black, white, so that is what you see, I guess.

Your brain also compensates for off-coloured lighting, perhaps it compensates for shadow to help you see into darker areas.

last edited by Idol at 08:09:12 18/May/07

Yeah they're the same colour. I even tried this with photoshop colour picker and I was shocked to see that they're the same.

what about all the other blocks in the picture?

This is so f***ing old, i cannot believe you fags haven't seen it before.

That's your comment to everything tho casa.

they are not the same colour, you can tell just by looking.
QFT

Man in Black: All right. Where is the poison? The battle of wits has begun. It ends when you decide and we both drink, and find out who is right... and who is dead.
Vizzini: But it's so simple. All I have to do is divine from what I know of you: are you the sort of man who would put the poison into his own goblet or his enemy's? Now, a clever man would put the poison into his own goblet, because he would know that only a great fool would reach for what he was given. I am not a great fool, so I can clearly not choose the wine in front of you. But you must have known I was not a great fool, you would have counted on it, so I can clearly not choose the wine in front of me.
Man in Black: You've made your decision then?
Vizzini: Not remotely. Because iocane comes from Australia, as everyone knows, and Australia is entirely peopled with criminals, and criminals are used to having people not trust them, as you are not trusted by me, so I can clearly not choose the wine in front of you.
Man in Black: Truly, you have a dizzying intellect.

^^^ Well done, "Princess Bride". Classic movie.

casa's sandy vagina washer is broken. give him a break.

obes is old, and thats the truth!

that's freakin cool, I didn't believe it until I checked the colours with a colour picker

Your brain also compensates for off-coloured lighting, perhaps it compensates for shadow to help you see into darker areas.

Thats probably the most relevant thing to this optical effect. A human knows that a surface colour is continuous regardless of the different 'colours' (i.e. shades) that the retina is picking up.

last edited by 3dee at 11:45:51 18/May/07

they are not the same colour, you can tell just by looking.

i guess that is what makes it an optical illusion :P both blocks are #787878.


obes : nah casa's comment to everything goes more like this ...
*whine*bleat*bleat*bleat*cry*dive* ... at least that's all i read it as ;D

For ppl who just dont get it and the non-believers :)

http://members.optushome.com.au/nickr/images/optical.png

They are.

Cut out a bit surrounding the A and the B and paste them next to each other on white background.

this forum has been infiltrated by wizards! get... out...of ... my... head

Here:

http://i182.photobucket.com/albums/x31/Hogfather_UTC/optical1.png

holy f***

now you have just coloured it all in. this is getting ridiculous.

what the hell is going on here?!

While I'm at it ...

http://homepage.powerup.com.au/~boldajis/images/stereo.gif

it's a shark!

i just found out i have epilepsy. thanks.

Carcharodon carcharias, 26years old and measuring 4.8m long weighting 1590kgs. Has scar on the left side of the dorsal fin and three teeth missing.

i could never do those things :(

i agree wtih casa

u guys all sux at the intenets

emo fanboi^^

As soon as I saw it I instantly knew they were the same.

If it's a trick then maybe I have super vision :O oooH!

last edited by Marty at 13:18:34 18/May/07

Explanation:

The visual system needs to determine the color of objects in the world. In this case the problem is to determine the gray shade of the checks on the floor. Just measuring the light coming from a surface (the luminance) is not enough: a cast shadow will dim a surface, so that a white surface in shadow may be reflecting less light than a black surface in full light. The visual system uses several tricks to determine where the shadows are and how to compensate for them, in order to determine the shade of gray "paint" that belongs to the surface.

The first trick is based on local contrast. In shadow or not, a check that is lighter than its neighboring checks is probably lighter than average, and vice versa. In the figure, the light check in shadow is surrounded by darker checks. Thus, even though the check is physically dark, it is light when compared to its neighbors. The dark checks outside the shadow, conversely, are surrounded by lighter checks, so they look dark by comparison.

A second trick is based on the fact that shadows often have soft edges, while paint boundaries (like the checks) often have sharp edges. The visual system tends to ignore gradual changes in light level, so that it can determine the color of the surfaces without being misled by shadows. In this figure, the shadow looks like a shadow, both because it is fuzzy and because the shadow casting object is visible.

The "paintness" of the checks is aided by the form of the "X-junctions" formed by 4 abutting checks. This type of junction is usually a signal that all the edges should be interpreted as changes in surface color rather than in terms of shadows or lighting.

As with many so-called illusions, this effect really demonstrates the success rather than the failure of the visual system. The visual system is not very good at being a physical light meter, but that is not its purpose. The important task is to break the image information down into meaningful components, and thereby perceive the nature of the objects in view.

http://bjo.bmj.com/content/vol86/issue2/images/medium/01465.f1.gif
This Sight has an easier explanation along with some animated gifs showing the illusion in action.

last edited by Tollaz0r! at 13:41:28 18/May/07

You dumb bastard, it's not a schooner, It's a sailboat.

http://www.guzer.com/pictures/male_optical_illusion.jpg

Here is an illusion that was brought to my attention. The effects of which some people claim still haunt them days, weeks and, on another forum I visit, even a year later.
CAUTION IS ADVISED

It still works on me a few months after I first saw it :(

that was s***

this is a much better colour illusion and it doesnt take minutes of staring at s***

http://www.johnsadowski.com/big_spanish_castle.php

thats neato ^^

cool - im impressed.

that was s***

this is a much better colour illusion and it doesnt take minutes of staring at s***

http://www.johnsadowski.com/big_spanish_castle.php

lol.

It's not an optical illusion, it just looks like one.