The Commuter Challenge

2 September 2013

The September 2013 Challenge

by CC @ 11:20

Create and submit an optical illusion. You may submit it in any format you like (drawing, photo, video, etc). There is no extra specification/constraint. A completely original optical illusion is preferred, but derivative and/or homage submissions are also acceptable.

The Results

Ryan Finholm

Impossible Crate


Three Balls

Brian Raiter

Impossible board(s)

Ambiguous Pyramid

Similar to a Necker cube, this figure displays an ambiguous pyramid. It can be seen either as a square pyramid viewed from above, or as a tetrahedral pyramid viewed from alongside, looking at one of its edges.

Clicking on the image will add shading that helps clarify each of the possible viewpoints in turn.)


  1. My “impossible board” is a minor variation on the famous impossible widget. The impossible widget can’t be rendered as a photograph because it relies on solid section turning into spaces (and vice versa). I wanted to create a version in which the “spaces” could still be represented by solid sections, and thus be possible to render photographically (with editing). Unfortunately, I picked a bad photo for my raw materials: the lighting is too even, making it hard to see some of the edges. Unfortunately I didn’t leave enough time at the end of the month to try again with another photograph.

    My second entry, the ambiguous pyramid, is technically not a legal submission, because I didn’t create it during this month. In fact, I invented it back in the fifth grade. I was very proud of it at the time, though. So I felt I owed it to my younger self to include it in this month’s submission.

    by Brian — 1 October 2013 @ 21:19

  2. Neither of my submissions are completely original ideas. The Impossible Crate is a very common image as optical illusions go, but most (if not all) of the other examples you’ll find are illustrations, or photoshopped to give them their ‘impossible’ quality. The image I submitted is an undoctored photograph (though I dinked with the brightness and contrast a nominal amount — all of the other Commuter Challenge entries that I submitted as photographs have had significantly more image correction than the photo I submitted this month). The crate is made out of old business cards I cut up, and I suspected that it wouldn’t work at all until I actually saw the photo. I was surprised at how much skinnier the ‘impossible’ vertical section (pasted to the upper front horizontal bar) had to be to make it blend with the back vertical bar just a few inches behind it.

    The Three Balls is my take on a forced perspective illusion, and is at least a little more original than the Impossible Crate. The blue ball is about half of the size of the other two balls, held in midair by a length of straightened clothes hanger wire. The wire is directly behind, obscured by the ball, and attached to the chair beside the table. There is another, full-size blue ball right where the front ball actually appears to be; that was done in order to provide a shadow in the correct place for where the ball is supposed to look like it actually is, and also to make it look like there is a hook attachment on the smaller ball, when that area is actually facing opposite the camera (because that is where the opening for the hanger wire is – no Xmas decorations were harmed during the filming of this illusion). You may or may not have noticed that Andrei’s pinkie finger appears to go in front of the hook attachment but behind the ball.

    The first attempts at shooting the video were at night, and it was a real headache getting the lighting right to avoid the shadows that might give away the illusion. It was much better in the daytime, because the lighting just looked better, and because there was so much ambient light around that most of the shadows were gone anyway.

    Special thanks to my talented and patient hand model Andrei.

    by RyanF — 1 October 2013 @ 22:59