Best ever optical illusion

[Mirc]

Edit:Crosspost with Rambuchan.

 

[Heretic_Cata]

Holy crap
The "+" dissapeared. I found mine too.

BTW - nice site mirc.

 

[Mirc]

Hey I see the other ones!

Crosspost. Thanks! And congrats for your 600th post (which will come soon)

 

[Chukchi Husky]

I don't see anything.

 

[Mirc]

You didn't stare enough.

 

[Chukchi Husky]

I stared for one minute.

 

[Mirc]

Do you use the Modern CFC skin?

 

[Heretic_Cata]

Hey, i've been staring at the red heart and when i looked on the right i could see a cyan heart. Strange. And also - when i was staring at the red heart it seemed to be turning darker.

Also - 600 posts

 

[Chukchi Husky]

I opened the image in a new screen.

 

[Rambuchan]

Explanation of the colour theory based trick for those who don't want to check the link:

Basically the three colours I made those hearts are the three primary colours: YELLOW, RED and BLUE.

If you have those three (pure) pigments you can create any other colour in the visible spectrum. Now these colours all have their opposites, as follows:

Red - Green
Blue - Orange
Yellow - Purple

You are wondering how you can make the colour grey from Red and Blue and Yellow right? Well, if you mix up the opposing colours in the following ratios, you will end up with a perfect midtone grey (must be pure pigment though)!

Red - Green ~ 1:1
Blue - Orange ~ 2:1
Yellow - Purple ~ 1:3

This weird logic is what is happening in the illusion too. So you should end up seeing hearts of the OPPOSITE COLOUR on the white side after your staring session. How so? It's the way the retina and brain processes colours, click the link previously provided for more.

This is why putting green up against red in a painting, adverts, movie or whatever guarantees you attention from the human eye. A nice pair of boobies helps too

 

[kingjoshi]

But while Red, Yellow and Blue are considered the primary colors, the eye's three primary colors are red, green and blue. The cones in the eye measure spectrum in the visible light for those three colors. And there is a intertwinement of red and green from the "seeing" part to the "perceiving" part. That's why some people are red/green colorblind.

 

[Rambuchan]

Can you elaborate a little more please joshi? Anything on why such colours are opposites?

 

[kingjoshi]

Ram, if you're interested in art (which it appears so), you really should study a lot about human vision and psychology. My friend just graduated from an art school and he was required to take "intro" courses on it.

I've forgotten so much of what I've been taught, I can't give a fair shake without relearning some of the stuff. And right now, I become lazy..

But quick idea is simple. You have three types of receptors (for Red, Green, Blue). There are millions of them in each eye. So they determine how intense each color is. It's similar to how the colors work on a computer screen with RGB. The way to get an "opposite" color is to reverse the values.

So pure red is intense red (value of 255 out of 255) and absense of green and blue (each 0 out of 255). The Opposite color would be no red and instense green and blue (0,255,255). That color is cyan.

That's basically how humans and computer screens operate. But art has been using Red Yellow and Blue as the primary colors for a long time. And publishing does the opposite. They use cyan, magenta, yellow and black. It's called a subtractive model while RGB is an additive model. That's because publishing and art is done on white and you need to get darker colors to view it, while the additive method, you add colors and arrive at white (RGB values of 255,255,255 is white).

Also an interesting note, what color you see is actually the color the object reflects. Or in essance, it's the exact opposite color of the object.

 

[Kal'thzar]

Possibly due to the overlap of said cones.
EDIT: well nm then

 

[Rambuchan]

kingjoshi: Thanks a lot. That's all very fascinating and informative. FYI: I spent a lot of time (and money!) studying art as a whippersnapper. It was at school that I learned the colour theory stuff (15yrs old) and it was at uni that I learned more about absence of colour (when using filters in photographic darkrooms to get the right balance on colour prints). Man did I spend a lot of time in those darkrooms!! But I never really went into the biology or physics of the eye, we were too busy looking at the chemistry behind paint and celluloid. Plus the psychology of imagery association, oh and all that gaseous art history stuff, of course!

 

[Mathilda]

Hmmm.. I stared at the blue one, looked to the right and saw the yellow one

 

[Mirc]

I knew that television uses Red, Green and Blue, while the human eye is better and it can make all the colors out of 2, not 3.

 

[kingjoshi]

Hmmm.. I stared at the blue one, looked to the right and saw the yellow one

The visible light spectrum goes like this:

In the absence of blue, we have both red and green. That creates yellow. The "opposite" of blue.

BTW, there is no "true" red, green or blue wave. So different cones in the eye detect different waves but within some degree of red, green and blue.

 

[Rambuchan]

So where does this idea of "pure pigment" meet with the physics and biology of those cones?

 

[kingjoshi]

Doing a search for "visible light spectrum" sheds some light on the issue.

Here is another imsage of the same information. I assume the most practical way to get a "pure" color is by taking something in the middle of the range. For example, blue has a range of 450 to 500 nanometers. Might as well take 475 nm as "pure". If you're designing a monitor and your device that does the emission is off every now and then, then that room for error would be helpful.

EDIT: That image doesn't really show cyan very well.

You can always go to wikipedia for help. They have info on the visible spectrum.