Sunday, November 09, 2008

Optical Brightness Illusions, and Hazyness

These optical illusions are so great that they have the privilege of gracing my new wall.

The gray Diamonds are all the same shade of brightness.
Note the much stronger effect in the upper one.

The gray rectangles inside are the same shade of brightness.

Below is my current all time favorite.

The two inside diamonds are identical.

Unlike the normal illusions of brightness, this time one of the diamonds appears "Hazy" quite an impressive feat. It takes some nuance to explain why this happens (E. H. Adelson 2000), but the other illusions are easily explained by the similar illusion below:

If you were to see this in real life, the actual reflectance of B would be lighter than A, and so your brain computes this and tells you that its brighter even though on the screen they have the same brightness.

These are fake-motion drawings:


  1. Am I the only one who finds the phrase "current all time favorite" amusing and somewhat contradictory? Perhaps it's just an illusion.

  2. Just wondering, what did you do with your old wall?

  3. i stand by my statement that this *is my current all time favorite :)
    I have a small number of "old walls" in various places around the world

  4. Like you have "old rooms" in various places all over the house.