If you haven't seen it, you will not believe it...

[Bob Hubbard]

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

 

[Obliquity]

I can see it if I squint just right.

 

[MBuzzy]

I can see it if I put it in paint and erase everything other than those two squares....That one is crazy!

 

[Makalakumu]

Heh. That is cool. Thanks Bob. I'm going to use this in my physics class when I talk about color. Basically, the way our eyes evolved doesn't allow us to see the full spectrum of colors. We only have sensory cells that pick up photons in the green, blue, and red wavelengths. So, how do we "know" what the other colors really look like? Our brains are just estimating. Further, why did the colors that we can't "see" come to look like they do?

These are pretty provocative questions.

 

[Sukerkin]

I see we frequent some of the same websites, Bob {as well as this one I mean :lol:}.

I've been fascinated by 'perception' and visual illusions for quite some time, an interest possibly sparked by my lack of 20/20 vision .

Because of a childhood illness, I see more red with one eye and more blue with the other, which makes it difficult debating what shade something purple, violet or lilac something is! Another side effect of the illness is that I'm blind (well, shortsighted) as a bat, with a focussing distance of about six inches.

These handicaps mean that I actually get to 'see' a broader spectrum of some of the visual illusions, especially those involving colour induced phantom movement.

One odd little factlet is that those trained for awareness and observation, such as martial artists, see more of the movement illusions too, as your eyes are subconsciously scanning more than normal.

A great site for all manner of illusions (and links to explanations) is at www.ritsumei.ac.jp. Have a look around for Akiyoshi's illusion pages. They're wonderful (but beware that some phantom motion illusions can make sensitive people feel ill).

 

[Sukerkin]

Here's a passle of links to other illusion sites:

http://www.brl.ntt.co.jp/IllusionForum/basics/visual/index-e.html
http://www.lhup.edu/~dsimanek/3d/illus1.htm
http://homepages.inf.ed.ac.uk/amos/visualillusion.html
http://www.kyb.tuebingen.mpg.de/bu/demo/
http://web.mit.edu/persci/
http://www.optillusions.com/

 

[jdinca]

I love stuff like that.