Have you ever seen the Pigeon Neck illusion?

[beschizza]

Originally published at: Have you ever seen the Pigeon Neck illusion? | Boing Boing

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[anothernewbbaccount]

Less ‘pigeon neck’ illusion and more ‘shake a tail feather’ illusion.
It looks like it’s the way the stripes come off the back of the bird that creates the effect.

[cannibalpeas]

[capnjimbo]

Embed on Bach’s site didn’t load for me, but the link to youtube (which I assume is the same thing) is this.

Pigeon-Neck Illusion

[NukeML]

In summary, human eyes have difficulty with low-contrast images.

[knoxblox]

[leicester]