Checker shadow illusion

The checker shadow illusion is an optical illusion published by Edward H. Adelson, Professor of Vision Science at MIT in 1995.^[1] The image depicts a checkerboard with light and dark squares. The optical illusion is that the area of the image labelled A appears to be a darker color than the area of the image labelled B. However, they are actually exactly the same color.

This can be proven using the following methods:^[2]

• Opening the illusion in a image editing program and using the eyedropper tool to verify that the colors are the same
• Isolating the squares. Without the surrounding context, the effect of the illusion is dispelled.
• Using a photometer

Areas of the image A and B are the same color

A rectangle of the same color has been drawn connecting the two areas of the image

See also

• Chubb illusion
• Lilac chaser
• Psychophysics

References

1. ^ Adelson, Edward H. (2005). "Checkershadow Illusion". http://web.mit.edu/persci/people/adelson/checkershadow_illusion.html. Retrieved 2007-04-21. 
2. ^ http://web.mit.edu/persci/people/adelson/checker_more_evidence.html

External links

• A high resolution remake of the illusion
• Video proof
• Real-life Proof
• Explanation of the effect
• Illusion of colours
• Video animation
• Alternative animation of the illusion
• An interactive presentation of the effect
• An interactive click-and-drag demonstration of the effect