Amazing Brightness Constancy Effect

Look carefully at the saw-tooth wave patterns on this picture. Is the background of the picture uniformly gray or are there different shades of gray?

Kolozanges (2013-2021), © Gianni A. Sarcone

Brightness constancy makes some vertical strips look darker, when in fact the gray background is all the same shade of gray.

This op art work is available as prints and canvases from my official online Gallery.

Is Magenta a Real Color?

Most of us are familiar with magenta — it’s a kind of purplish-red that exists between blue and red on color wheels (color wheels don’t accurately represent the physics of photons, but they represent the philosophical reality: color is a human construct that helps us interpret wavelengths to better understand our world).

The odd thing about color vision is that magenta (or pink) color is not in the spectrum of colors, meaning it cannot be generated by a single wavelength of light. Our brains interpret the color sensation of magenta/pink as ‘absence’ of green.



You Can’t Possibly Color This!


An Impossible Optical Illusion Activity Book

No mere coloring book, You Can’t Possibly Color This! is an eye-spinning experience that will inspire and astound. That’s because you’ll be coloring in optical illusions — things that can only exist on the page. With a just a few tips, you’ll be coloring in things that will bulge, expand, and even rotate. Other objects will leave you confused as you try to figure out the “trick,” while mandalas, complex patterns, and labyrinths will mesmerize you. Also included are fun activities for drawing and creating your own optical illusions.

Continue Reading

Illusive Op Art Skulls

I am currently working on new “neon color spreading” effects. Have a look at the pictures below… Though you perceive fluorescent grinning skulls, the vertical white stripes don’t contain any color at all, they are uniformly white! The trick lies on the fact that some black lines have very thin color edges. This illusory shading effect is also known as “subjective transparency” or “Tron effect”.

The neon color effect was first observed by D. Varin in 1971. The human ability to perceive a neon effect may be a remnant of the development of our power of sight under water at extreme depths, where light is very poor.

My Op Art Skulls are available as prints and t-shirts from my online store.

Continue Reading

Different but Equal

It happens sometimes to read on a snack the following notice: “with chocolate taste”, written in uppercase. This statement tricks our mind! In fact, the vast majority of us think that such a snack MUST contain chocolate, no one thought however that a flavor is not a substance and most probably the snack we bit into contains only an ‘illusion’ of chocolate.

The same occurs with colors, our brain is easily tricked by them. Colors are just like ‘flavors’, they may smell, pardon… look like a specific color, but they are just an illusory subjective sensation, not an ‘external’ reality. Colors undoubtedly change depending on their surrounding or the context in which they are viewed. More mind-blowing still is the fact that colors that are identical may appear to be different under certain conditions, and colors that are different may look the same. Such a curious effect is called “color induction”. Continue Reading