The main goal of this project is to show the Muller Lyer illusion using video and sound: the visual part enhance the experience with the audio illusion while the audio part provide a more concrete experience of the visual part. We animated the "arrows" so that they seem to be shrinking while moving upward. In order to deepen the experience of the illusion, we made a Shepard tone that the pitch of the tone seems to be moving upward forever.
We selected the Muller Illusion as our main topic of the project. Basically, Muller Illusion consists of s set of arrow-like figures with fins pointing inward or outward. Although the straight line segments are of the same length, people tend to think that the arrow with fins pointing inward is longer. This s because our visual system judge the depth and distance of things we see constantly. Our subconscious makes us to believe that line with fins pointing inward is farther away and therefore longer.
Another perceptual illusion we use is the Shepard tone (also called the Shepard scale). The Shepard tone trick listeners to believe that the tone is continually ascending in pitch, although in fact the tone does not get any higher. This illusion is achieved by combining a higher tone and a lower tone into one. When the pitch goes up, the lower tone becomes louder and louder and eventually superimpose the higher one. Therefore the overall pitch of the tone seems to be going upward forever.
We first came up with the idea of the Shepard tone. And the fact that the pitch of a Shepard tone is constantly going upward lets us think about making a sequence go images moving up. First we considered using the image of the mug, however a moving mug does not really qualify as "poetic" or "beautiful". Thus, we reconsidered and decided to use the Muller Lyer illusion, which was actually the topic of Fred's last project.
For the visual part, we first tried to use Photoshop, which turned out to be more complicated than expected. So we changed to use Python. We were afraid that the "shrinking" effect won't be too obvious since the straight lines are close to each others and a viewer can easily compare the lengths. Fortunately it worked in the way that the lines do look like shrinking. Finally we made little adjustments to make it simple but still elegant. To illustrate the effect online, we used quickTime player to take screen video and then add sounds on it.
For the sound part, we searched on the Internet on how to construct a Shepard tone. We tried several times to construct one on our own but all failed. So we took several video/sound trek from youtube and used Adobe Premiere to chop off the sound and adjust it to more properly fit our need.
We are quite satisfied with our final outcome. It is beautiful because of its simplicity and continuity. We definitely achieved our goal to trick the viewers to believe that the arrows are shrinking in length while the pitch of the tone is going upgrade forever. This video can be played forever. There is a minor issue: while the visual part (the arrows) is moving smoothly, the sound trek is not. Other than this, we think we've created a interesting and poetic piece of work.
The three of us collaborated well on this project. It's harder than we thought to turn a illusion into video motion though. And in order to achieve the effects we want, we had to made tons of adjustments. Through this project, we get to explore more the general concept behind the Muller Lyer illusion and learn how to utilize what we learn to build our own preceptorial illusion.
Actually, it's quite interesting to combine images and audio because before I didn't expect that the effect of combination is not just to add them together. If we choose audio and video with similar effects properly, we can have much stronger effect on people because our brain does not process images and sounds separately. Instead, we sense things using sounds and images together.
Reference any sources or materials used in the documentation or composition.
https://en.wikipedia.org/wiki/Shepard_tone
https://en.wikipedia.org/wiki/Müller-Lyer_illusion
http://ideate.xsead.cmu.edu/gallery/projects/penrose-triangle
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