The optical illusion above was created by using a filter moving across a composite image. The video below shows you how to create this type of illusion.
Illusions tell us something about how our visual systems process the world around us and can help us to understand conditions where vision doesn’t work properly (e.g perceiving moving objects when there are none). The illusions above are interesting in that the brain perceives a rotational movement as the filter moves sideways.
The illusion reminded me of the zoetrope. The movement in the illusion above occurs because the sheet moves across the stationary image whereas in the zoetrope the images are moving in space. However there are filters in both cases that order the images across time to create the illusion. Recent examples of zoetropes use stroboscopic lighting in place of the line filters.
How to Create a Zoetrope
The BRAVIA-drome – An Example of a Zoetrope
The zoetrope is similar to films. Films and moving images are now pervasive. Considering the illusions above reminds us that when we watch a film we are using a technology which works because of our biology. Developments in the field of psychophysics contribute to film and television. The above illusions give us an insight into the building blocks of our biological visual motion processing.
Earliest Film (1888)
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