The Force Awakens tonight in the US, and if you are like me, you may have waited up to 32 years to find out what happened to the Republic and to our heroes Luke, Han and Leia after the death of Darth Vader and the demise of the evil galactic Empire. Now the wait is finally over, and in preparation for the celebrations, you and many of your Facebook friends may have updated your profile pictures with impressive looking blue or red lightsabers. Here’s mine:

Once I finished rejoicing in my newfound Jedi status, here’s what I noticed: the central part of the lightsaber looks much lighter than it should—lighter in fact than the white background (of the same luminance). This whiter-than-white seems to blind the viewer with the sheer power of the Force, which is clearly not possible. The white in the middle of the lightsaber can’t be any whiter than the white background that your screen generates.

Pending further research, the lightsaber illusion seems related to the Ehrenstein Brightness Illusion, as well as to some of the images devised by the Spanish artist Din Matamoro. Matamoro’s 2005 series “Solar Light” (from “Mental Images”) appears to portrait the sun coming out from behind the clouds, in magnificent brightness. The images, even in their printed version, make you want to squint your eyes in fear of pain. (A bit like you’d feel if you were facing the blaze of a lightsaber). 

Ehrenstein Brightness Illusion: The illusory circle in the center seems whiter than the background
Imágenes mentales, serie Luz solar, 2004, by Din Matamoro

These images, and the lightsaber illusion, may also be (more distantly) connected to the “Here’s the Sun” illusion, created by Alan Stubbs, and one of Top 10 finalists that competed in the 2006 Best Illusion of the Year Contest.    

                                             Here’s the Sun, 2006, by Alan Stubbs

To experience the “Here’s the Sun” effect, look at the center of the red-and-blue pattern (you can think of the colored rays as red and blue lightsabers, if you like). Then move your head closer to the screen. As the image approaches you, you will see that its apparent rightness increases. Now move your head back and forth a few times to make the brightness go up and down repeatedly. 

Enjoy the illusions, and may the force be with you!