Shadow Optical Illusion: Are Your Eyes Deceiving You? (VIDEO, POLL)

This trick's been around for a long time as an image, but this YouTube video seems to bring the whole illusion to life.

The mind-blowing shade experiment is based off this template, which almost seems too simple to work. But if you watch the video below, we dare your mind not to be blown.

According to the YouTube posting the initial idea was brought to light by MIT professor Edward H. Adelson. The post's description also attempts to further explain the illusion, though it's still hard to believe, even when you know what's going on.

We think this illusion's a bit more believable than this one, whether or not you think it's real is your decision to make.

WATCH:

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Is this real or just incredible video editing?

Real!

It's all a lie!

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Comments

[rafaelrobyns]

10:42 PM on 08/27/2011

@canuknotusa: you seem to be trying to hard to provide a proof against something that isn't claimed. The only claim is that the squares are the same color. If this fact is easily demonstrated in Photoshop, then it wouldn't be necessary for them to fake anything. Why would they?

[Canuknotusa]

05:25 AM on 08/28/2011

Yes - I seem to be obsessed with this… Sorry! I just don't agree that nothing was 'faked' in this video.

The squares actually AREN'T the same colour, because they are part of a checkerboard grid. What would the floor look like of the barrel were removed? Would the two squares be the same colour?

They only have the same APPARENT colour if the light one is in the shadow and the dark one is in the light.

[rafaelrobyns]

11:45 PM on 08/28/2011

I see your point. But the lighting in the shot makes me think that there isn't really a shadow, but rather a shadow pattern incorporated into the tiles. When the video starts you can see that the side of the barrel away from the bright light is actually well lit by a light from above. You can also see that there is no equivalent heavy shadow cast by the barrel from the light above. I think the illusion happens because your eye is tricked into thinking there is a shadow when there isn't, not that they have faked something during the video.

[Canuknotusa]

07:39 PM on 08/26/2011

The illusion here is that the two different coloured squares in the grid (one is ACTUALLY light grey and the other is ACTUALLY dark grey) become the same colour when one square is in the shadow.

This doesn't appear to be true, but if you take a PHOTO of the scene and cut out everything but the two squares, you can see that they are indeed the same colour. The illusion is created by our brains being fooled by the SURROUNDING squares.

BUT…

In this video, the two squares are NOT compared with one being in the shadow and one not.

The square in the shadow is MOVED into the light, where it is compared with the other square. The squares are compared when BOTH are in the LIGHT.

Since the two squares are ACTUALLY DIFFERENT colours in the grid (see the first sentence), they CANNOT be the same colour when compared in the LIGHT.

Therefore the video is faked.

To confirm this, just take the shadow away and look at the two squares that were compared. They would NOT be the same colour when the shadow it not there, as log as the grid is composed of alternating light and dark squares.

You figure out how they did it. I have my own theory.

[Nelle]

04:58 PM on 08/26/2011

Whoa, Nelly!!!

[lmab]

01:22 PM on 08/26/2011

Now I understand the whole C l a r e n c e T h o m a s thing.

[Canuknotusa]

08:44 AM on 08/26/2011

Fourcents,

I apologize for losing my patience with you. I was rude.

Sorry!

[duca argento]

10:21 AM on 08/26/2011

From 0:57 through 1:09 all of the "shadow" which is apparently being cast onto the checkerboard has been PREPAINTED ONTO THE TILES. The entire floor is evenly illuminated from above. The tile is not being moved out of the "shadow" into the light.

[Canuknotusa]

10:28 AM on 08/26/2011

Yes - that was my observation a few days back.

But whatever the method, the fact is that the video does not represent a true, unaltered version of this well known - and perfectly legitimate - illusion.

[Fourcents]

01:09 PM on 08/24/2011

Me again. Too curious to let it go. Looked it up in Wikipedia.

The two square are EXACTLY the same color. Moving the card produces the optical illusion. In the Wikipedia video they take the scene and erase everything gradually leaving only the two squares and they are the same color.

This is the "grey card" effect I referred to in my earlier post. I know it looks impossible but check the Wikipedia they are exactly the same color. That 17% grey card compensates for the human eye's ability to adjust and be disceived. Most pro photographers should get this one right.

This might be a good way to get another black guy elected President? We need a replacement Dem. IMHO (^_=)

[Canuknotusa]

02:32 PM on 08/24/2011

Nor sure what you're getting at with the 'grey card' discussion…

But I agree that the two squares are the same shade of grey - and nothing would be wrong with this video if they left them in place.

But as soon as they MOVED one card out of the shadow and into the light, the validity of the video vanished. It essentially showed that a light grey square in the grid was the same colour as a dark grey square in the grid when both were viewed in the light.

That's why the video has to be faked.

[Fourcents]

02:48 PM on 08/24/2011

That is where your eye gets fooled and my grey card reference. Go to the Wikipedia site. Hard to explain. If you look at the pic you can almost imagine reality. Human eyes adjust to compensate and we cannot stop them from doing so. Check Wikipedia they show another video of the same scene but it reveals the illusion. If you took a pic and erased all but the two squares in question they are identical. It is the act of crossing the shadow line that you eye fools you not the video. We have met the culprit. It is us!

[Fourcents]

12:26 PM on 08/24/2011

I could be wrong. Best guess: This reminds me of the 17% grey card in photography.

It is a neutral color that reflects true colors in sunlight and shade. Here the card is moving from shade to light which is that 17% difference? In the light it is 17% brighter? Pretty sure because it looks just like my Grey Card used to set light compensation/dark compensation in my digital camera.

Buy that? ...........I don't blame ya, LOL

p.s. Put "grey card photography" into Google. They explain better than me.

[alamacTHC]

07:49 PM on 08/23/2011

Oh how stupid. A clear piece of plastic gets laid over two different colored squares and--surprise!--it takes on their colors. The shade has nothing to do with it.

FAIL

[Canuknotusa]

03:42 AM on 08/24/2011

The video is faked, but you need to think your explanation through a bit. If the plastic was transparent, it would have been obvious when the girl moved it across different shades of tile.

[Blakguy]

07:48 PM on 08/23/2011

The moving shadow by her leg blew the camera tricks.

[Mark Herrmann]

05:55 PM on 08/23/2011

This is fake, even though the "light" tile within the shadow and the "dark" tile within the light ARE the same value.
If you moved the "light" tile in the shadow into the light, then it would match the value of the "light" tile in the light, not the "dark" one.
Also, if you look closely around 1:06, you can see that as she moves the tile into the shadow, it gets a little darker (as it should) but THEN a little LIGHTER as it still goes further into the shadow.

[Canuknotusa]

06:07 PM on 08/23/2011

"If you moved the "light" tile in the shadow into the light, then it would match the value of the "light" tile in the light, not the "dark" one."
-----

BINGO!

[Canuknotusa]

04:23 PM on 08/23/2011

Thank you

[Canuknotusa]

08:25 AM on 08/23/2011

The video is FALSE for the following reasons.

1. The two tiles compared occupy a LIGHT and a DARK position on the checkerboard grid. The tiles themselves CANNOT be the same colour when viewed under the same lighting conditions, otherwise the checkerboard pattern would not be possible.

2. The illusion this video is trying to demonstrate is that the *apparent surface shade* of these two different tiles is the same when one is in shadow and the other is not. Although the illusion is correct, it cannot be shown by moving both tiles into the same lighting condition.

3. The girl physically MOVES the tile from the shadow into the light to compare it with the other tile. This puts both squares into the SAME lighting condition and shows that the ACTUAL colour of these two tiles is the same.

4. Therefore, the floor grid would have 'dark' tiles next to each other in the area covered by the shadow. The illusion of the checkerboard floor must be maintained by placing a third, DARKER shade of tile next to the 'lighter' tiles in the shadow. This is the only way for the floor to appear to be a checkerboard pattern.

This video is NOT repeatable with a standard, true checkerboard grid that consists of only two shades of floor tile and using a real shadow to illustrate the illusion - therefore it is FAKE.

[Fourcents]

01:33 PM on 08/24/2011

Canuknotusa my friend, you have gone to considerable trouble "exposing" this "trick". Take a little time to look it up in Wikipedia. They have a video of this scene.

By erasing everything in the picture gradually you will find that the two cards, one in light the other in shade, ARE EXACTLY THE SAME COLOR ALL THE TIME. It is our eyes that disceive us, honest, cross my heart, LOL

In photography we use a 17% grey card that allows the camera lens to adjust for existing sun in light and shade areas because our eyes are not capable of doing it so we can tell the camera. My grey card is the same color, not colors, as in the video. Notice the scene kind of looks like it might be in a photo-studio?

Your show a lot of potential for developing conspiracy theories, LOL Laugh with me and look it up in Wikipedia. It is weird watching all the other cards disappear until only those two are left and they are the same. (^-^) /

[Canuknotusa]

05:33 PM on 08/24/2011

For heaven's sake! I wasted a decent amount of time trying to find this 'video' because I thought it compared with the one in this article!

I've seen this illusion many times before - and TOTALLY agree that the two squares are indeed the same colour when compared IN PLACE.

My issue is with THIS video, which compares them after moving one of the squares out of the shadow and into the light!!

You haven't read any of my posts on this, have you!

[SLivermore]

06:53 PM on 08/22/2011

This story seemed pretty "meh" to me until I started reading the comments. Now I am increasingly convinced that the real story is the degree to which the anti-science movement has taken hold. :/

[Canuknotusa]

08:48 PM on 08/22/2011

It's not your lack of scientific understanding that is the cause of your confusion - it's your unwillingness to observe what is really going on and apply critical thought to it.

**The illusion is real** The two tiles appear different when surrounded by lighter or darker neighbors. That is undisputed - and was proved long ago when the 2D version of this experiment first made the rounds.

BUT - in this video, the two tiles taken from different places in the checkerboard floor are shown to be the SAME SHADE when seen under the same light. This is not possible unless the shaded tiles have been manipulated and a third, darker shade added to maintain the checkerboard illusion.

In an unaltered checkerboard floor, a simple shadow would not change the actual colour of any of the tiles.

[Mark Herrmann]

06:17 PM on 08/23/2011

I don't think that there is a 'third darker shade' but I do know that this is fake.
I think what they did is very slightly (nearly unnoticeably) alter the value of the moving tile in each frame as the girl moved it so it wouldn't appear to gain or lose value even though it should.

[Ganymede425]

06:48 PM on 08/22/2011

One way to defeat an illusion like this is to look at it without focusing your eyes on any of the geometry, as if you are actually looking at something a couple feet in front of it. It prevents the relative contrast boost that you get when you actively focus on the squares. Doing it this way, the two squares in question will share the same shade of grey.

[SLivermore]

06:43 PM on 08/22/2011

It's real. I have a 2-D picture of the same illusion, and you can take a card with a hole cut over one of the "light" spots and one cut over one of the "dark" spots, and you can see, once the surrounding shades are covered up, that the two are the same shade. The brain provides extra "contrast" when we see it all together.

[Canuknotusa]

06:52 PM on 08/22/2011

Yes - the 2D version is a legitimate illusion. But it is comparing surface shades between a tile in a shadow and a tile in the light.

This version actually MOVES the tile from the shadow and places it in the light to compare it with the other tile.

The comparisons in this video are completely different from what your 2D picture compares.

In order for this video version to work, there must be a third shade of grey - the dark tiles in the shadow - to make the grid appear like a checkerboard.

[SLivermore]

07:00 PM on 08/22/2011

The 2-D version is the same, dear - nobody said that there were only two colors on the board. The "dark" grey square in the light is the same as the "light" grey square in the dark, in both versions. Everything else is the result of our brains interpreting information.

[SLivermore]

09:27 PM on 08/22/2011

The illusion is the same in the 2-D and 3-D versions. In the 2-D version, the tile in the "light" area and the tile in the "dark" area appear to be of different shades, but they are not. They are the same shade. It's just as if they are the same tile. And the possibility of there being three or more different shades of grey in the picture is irrelevant. The illusion = tiles that are the same shade appear to be different shades. It is manipulation - of visual information - by your brain.