The persistence of vision is the phenomenon of the eye by which an afterimage is thought to persist for approximately one twenty-fifth of a second on the retina. This phenomena is what allows us to see things like movies which appear to be fluid motion, and not the sequence of individual pictures that they actually are. There are a number of devices that take advantage of this to show motion. These include flip books, zoetropes, film projectors and thaumatropes to name a few.
The human eye sees around 50-60 frames per second. In film, it was scientifically determined that a frame rate of less than 16 frames per second caused the mind to see flashing images. The industry standard for film is 24 frames per second. Films have been shot in 24 frames per second since 1920. With the widespread use of 3D in films, a higher frame rate has become desirable. This higher frame rate helps to reduce the flicker seen when watching a 3D video.
I have always been interested in the early forms of animation. One of the most basic being the flip book. The flip book, and many of these other early animation devices are great at learning how animation works. You’re able to clearly see each frame that goes into the making of the final animation.
The thaumatrope was popular in Victorian times. It features an image on either side of a card. The card has two pieces of string which you can spin. When spun it gives the illusion of a single combined image.
Another interesting device is the zoetrope. A zoetrope is a cylinder that houses a piece of paper that has each frame drawn out on it. On the cylinder, there are slots that help to create flickering so you’re able to see the animation. Without the slots the animation would appear as a blur due to the drum moving too rapidly. Pixar has a really amazing 3D zoetrope built similarly to the Studio Ghibli one. Instead of a drawing or picture, each frame is represented by a sculpture.
Understanding these older forms of animation helps us better understand what is possible. A really interesting animation was done by Scott Benson called “We Always See It Too Late.” He took the concept of the zoetrope and built one digitally. The combination of old analog technology with new computer technology is really exciting and inspiring.