The Optical Illusions Thread

[Fzero]

Linked this from reading New Scientist this morning.


Some really good ones on here, you can also click through to see the previous years' winners and contenders too.


If you like optical illusions you will probably like some of these, some you will of no doubt seen but there, I've seen plenty but were some on here I hadn't.


The 1st prize winner of 2012 [The disappearing hand trick] was a good one, there's a video of it in effect, you need sound to hear what it's about.


The 3rd prize [Colour wagon wheel] is also good though I still don't believe it is moving the direction it claims to be


Warning: Spending too long on this site will send you loopy - probably.


Check them out: http://illusionconte...lcorrelate.com/


...And add on any of your favourite illusions.

 

[Nintendo]

WOW! Those 3 are awesome!!! You should change your thread/topic title to, "The Optical Illusions Thread".

Spoiler

 

[diligentcircle]

ArtDawgs's "I refuse to show the image" image isn't much of an illusion, SONY.

 

[Fzero]

Title changed...


Re-link your one Sony, ...you bloody bandwidth thief you

 

[commander-beef]

one man.. grandfather of illusions: M. C. Escher

 

[diligentcircle]

The 3rd prize [Colour wagon wheel] is also good though I still don't believe it is moving the direction it claims to be

You don't believe it? It's an extremely simple concept. Remember that nothing is actually "moving" at all; the dot positions are changed and the screen refreshes. Perception of movement is simply a result of the difference between the two images.


Now, given that the dots are all the same appearance and spaced 30 degrees apart, think of what happens when they move 25 degrees (or any distance between 15 and 30 degrees, actually); the position change is that every dot is moved to a position just counterclockwise of the next dot, but since you don't actually see that movement, this is visually exactly the same as all the dots moving counterclockwise 5 degrees. Since the counterclockwise direction involves less movement, your brain perceives the change as counterclockwise.


I don't know much about CRT screens, but I believe that the line you see moving up the screen when recording one with a camera is a very similar effect.

 

[Fzero]

I love M.C. Escher prints


...and the FamGuy sketch, "walking up the sideway stairs"

...About that Colour Wagon Wheel;


It's not actually moving at all then, just my mind filling in the gaps as it were?


I sort of get what your saying i think.


I will take another look at it now, now I have lost my nausea from checking it earlier.


CRT screens via a camera effect is interesting, I did read up on how that worked years ago.


Same sort of effect yeah

 

[Binky]

WOW! Those 3 are awesome!!! You should change your thread/topic title to, "The Optical Illusions Thread".

http://www.thedawgpound.com/wp-content/uploads/2011/11/albert_einstein_marilyn_monroe_vision_test.jpg

 

[Nintendo]

Thanks, Binks.

Title changed...


Re-link your one Sony, ...you bloody bandwidth thief you

http://www.kulfoto.com/pic/0001/0018/i8gYm17399.jpg

 

[Fzero]

http://www.youtube.com/watch?v=UirpkTAq3uY

 

[Nintendo]

I found this one to be a little silly and misleading in it's agenda.


http://www.maniacworld.com/Hidden-Tiger-Optical-Illusion.jpg

 

[Fzero]

...took me a little minute that Tiger one.


I was looking around the background thinking I was meant to be seeing something there, and then I clocked it

 

[Nintendo]

It's a bit lame if you ask me. Hardly an illusion, really. <_<

 

[WizardStan]

My problem with #3 (the wagon wheel one) is that the actual illusion in real life involves a spinning wagon wheel with continuous motion: the illusion happens because the moving wheel is just a blur as your eyes adjust to it moving. This illusion presented here is discrete: the wheel didn't rotate through the full 25 degrees really fast, it jumped straight from 0 to 25. Due to perfect symmetry the exact same effect can be obtained by rotating at -5 degrees; you can't do that with the real life wagon wheel: while the wheel kind of looks like it is going backwards when it spins forwards fast enough, it wouldn't look exactly the same in reverse.

 

[Fzero]

Just watching Horizons on BBC4 now:


Blink: A Horizon Guide To The Senses


Available to watch on the old iPlayer, probably only in UK[?] here:


http://www.bbc.co.uk/programmes/b01kptcr


Some good stuff, I hadn't seen the selective attention test before and it got me. The one on the Horizons was better I think but this old one is good still, give it a go..


You have to concentrate and keep count, as explained at start of clip

https://www.youtube.com/embed/G-lN8vWm3m0?feature=oembed

This episode also covered synesthesia a little bit, which I think is amazing even though it's probably impossible to actually imagine how it really is for those who live it


Good watch for an hour I'd say

 

[ZXDunny]

Go download the blue dragon from here:


http://www.grand-illusions.com/opticalillusions/three_dragons/


And then cut-out and make it. You will not believe your eyes. Or rather, eye. Seriously.


D.

 

[Fzero]

I actually had printed out that dragon a few years back and had it on the shelf at work - will make a new one as it goes as that one went AWOL, very good illusion desktop model

 

[erico]

Not much an illusion but great none the less.

https://www.youtube.com/embed/ubNF9QNEQLA?feature=oembed