NB this animation will currently not run with some browsers and systems – fix on the way. Animations in earlier posts should run on most systems
Here’s a copy with slight variations of a stunning new animation of the Ebbinghaus Illusion, by Christopher Blair, Gideon Caplovitz and Ryan E.B. Mruczek. Their version won the Best Illusion of the Year Competition in 2014, a few weeks ago. It’s a brilliant competition whose lead organiser is Susanna Martinez-Conde, and is accumulating a fascinating illusion resource as the ten finalists are added each year.
In the movie, as the figure moves up and down the screen, all the circles seem to change size. Yet objectively only the outer ring of circles do so: the central circle remains exactly the same size throughout. It’s so vivid it’s hard to believe, but I’ve just added some yellow rails as a track for the central circle. You can see that the circle always just fits the rails – and they don’t change size.
For more info and links on the Ebbinghaus illusion (aka Titchener Circles) see our earlier post on the traditional, static version.