Here are some information about the shadow illusion, also called the checker's shadow. This subject is related to the optical illusions. The brain could be tricked to perceive things that aren't there. Below is an example. It's amazing how the psychology of the mind works. To see other examples check our Brain Tricks main page.
Tips for the shadow illusion: You will, in all likelihood, perceive the above picture as a 3-dimensional scene, where a greenish cylinder stands on a checkered plane; light comes from top left.
Now try the first button (“Question 1”) on the top right. Two patches will be indicated, and you are asked to compare their relative brightness. I think we can all agree that the top one is darker.
A second later a yellow mask will appear. Now you can compare the two patches without the 3-dimensional context. Now the brightness will be identical. The luminance is identical at all times, but the brightness (=apparent luminance) differs, depending on context.
Notes: When interpreted as a 3-dimensional scene, our visual system immediately estimates a lighting vector and uses this to judge the property of the material.
Trick of the Day: The moon when close to the horizon looks bigger than when it's in heart of the sky. That's because when it's close to the horizon, your eyes sees it in comparison to other parts of the horizon, such as trees, mountains and houses, and that's what makes it look bigger. For more tricks of the day check Tricks of the Day.
Other than the shadow illusion trick, the mind can be fooled in different ways within the subject of the optical illusions. It's no longer accurate to say "what you see is what you get". Now choose a related page, or simply click on previous/ next.