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Leaning Tower Illusion
The leaning tower illusion won the Best Visual Illusion of the Year Contest 2007 first prize. A simple illusion but strikingly novel. The two photos of the leaning tower of pisa are the same but one has the impression that the right side leans more.
Source: Neural Correlate
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December 13th, 2007 at 12:15 pm
Not that it would make much of a difference that I can tell, but those images are NOT identical. The tower on the left is taller by 1 pixel as I can tell. If you paste one image on top of the other using a blending using a difference mode, you can clearly find a line near the first set of arches that is different. The same effect coule have been demonstrated by actually using the same picture in the page source… this was just sloppy and calls into question if the result is valid or not.
January 18th, 2008 at 5:35 pm
The Leaning Tower pictures are NOT identical. Look at the arches along the very bottom of the frame. The pictures were either taken with a stereoscopic camera or were taken consecutively with slight camera movement. Defocus your eyes to merge the two images into a third image in the center and you will see a strong illusion of depth. If the images were identical the illusion would be much less. Defocus further to put the images slightly out of register, and you will see the differences in angle between features such as columns. This will be easier to spot with features closer to the camera.