Sensation and perception are always happening. Our eyes are constantly sensing the light energy, transducing it in the retina, and sending these neural messages up to the brain. From there, perception always happens. Both binocular and monocular cues are used throughout sensation and perception. The most important two monocular cues are motion perception and the Phi Phenomenon. Motion perception is the perception that larger objects appear to move slower than smaller objects. The Phi Phenomenon is the illusion of movement when two adjacent lights blink on and off, as illustrated below.
In the case of moving pictures, images are drawn as if motion was occurring. If you flipped through the images slowly, it wouldn't seem like the picture was moving. As the video emphasized, the thing that allows us to perceive moving animations is the rate of frames per second. When the rate of the images shown is between 8 and 12 frames per second, consistent motion can be perceived. At 24 frames per second, the motion seems fluid and, most importantly, real. This optical illusion has been in use since the early days of moving pictures. Images captured on film were played back at around 24 frames per second so that the pictures looked like they were moving. How cool is that? In time, the technology and understanding of this optical illusion seemed like common sense, so we didn't think about it as much. Next time you watch an animated movie or even a regular movie, take a moment to think about what your brain is sensing and what you are, in turn, perceiving.
I like what you said about frames per second. Were you keeping up with this stuff when they were making the Hobbit? The big deal there was that the hobbit was shot in 48 fps, which is double the normal rate. The goal was to make it super clear. There wasn't much of a consensus as to whether it really worked for it, or whether it was too much. What do you all think?
ReplyDeleteRachel, I obviously was keeping up with the making of the Hobbit! :) I actually totally forgot about the whole 48 fps deal. When I watched the movie, I actually felt that the 48 fps, 3-D filming, and excess amount of CGI made the movie look like a video game. Adding more frames per second just made the whole movie seem a lot less real. Regularly, the eye takes in about 20 images per second, but this number can increase to 60 fps if the person is in the midst of a fight-or-flight response. Honestly, it was a little unnerving to be shown so many frames per second. I couldn't just sit and enjoy the movie because there was so much going on and so many images to take in.
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