persistence of vision

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.

The myth of persistence of vision is the belief that human perception of motion (brain centered) is the result of persistence of vision (eye centered). The myth was debunked in 1912 by Wertheimer but persists in many citations in many classic and modern film-theory texts. A more plausible theory to explain motion perception (at least on a descriptive level) are two distinct perceptual illusions: phi phenomenon and beta movement.

A visual form of memory known as iconic memory has been described as the cause of this phenomenon. Although psychologists and physiologists have rejected the relevance of this theory to film viewership, film academics and theorists generally have not. Some scientists nowadays consider the entire theory a myth.

In contrasting persistence of vision theory with phi phenomena, a critical part of understanding that emerges with these visual perception phenomena is that the eye is not a camera. In other words vision is not as simple as light registering on a medium, since the brain has to make sense of the visual data the eye provides and construct a coherent picture of reality. Joseph Anderson and Barbara Fisher argue that the phi phenomena privileges a more constructionist approach to the cinema (David Bordwell, Noël Carroll, Kirsten Thompson), whereas the persistence of vision privileges a realist approach (André Bazin, Christian Metz, Jean-Louis Baudry).

The discovery of persistence of vision is attributed to the Roman poet Lucretius, although he only mentions it in connection with images seen in a dream. In the modern era, some stroboscopic experiments performed by Peter Mark Roget in 1824 were also cited as the basis for the theory.

how animation works

The very basics of animation are the same on all media. The first step is to show an image. All following steps include minor changes to the previous image. When shown one after the other relatively quickly, the image can appear to be animated.

Animation is a series of many, many pictures shown in rapid sequence to simulate movement. For example, Mickey Mouse appears to be moving because a picture is drawn of each tiny movement he "makes" in the scene. Hope that helps.

Visual Processing and Film 

Whether you're talking animation or live action photography filming, the basic science of moving pictures is the same. When a person views a moving object in real life, the human brain retains the image of a moving object for longer than that image is actually present. This creates an opportunity to convince the brain's image processing centers that a series of fast, still images are actually moving pictures. While live action filming takes a series of still, chronological images of moving objects to be played back in sequence, animation synthesizes this process through the creation of individual frames by artists. The human brain will perceive motion when watching a series of moving images presented at a speed as slow as 10 frames per second, but the motion will appear jerky. A rate of 16 images per second creates an impression of a moving image virtually indistinguishable from live motion.

Traditional Animation

Traditional animation is created when an animator, or group of animators, makes a series of still images which are photographed and used to create film, or played in a sequence using a computer program. Each individual drawing represents a fraction of a section of the progress of a moving image. The art of animation drawing is therefore highly complex because it requires not only the skill of drawing, but the skill of observing and capturing very gradual changes in movement and lining up each drawing accurately with the last. The process of hand animation is usually streamlined through the use of animation cells. An animation cell is a sheet of clear plastic which is laid over a finished drawing. The finished drawing contains the background of the animated scene and any objects that won't be moving during the scene, while a series of cells are painted with the progressive images of the characters and moving objects. This saves time by requiring the animator(s) to only draw multiple images of the few moving objects rather than the entire scene. It also keeps the background consistent.

theatre optique

In 1876, Reynaud, a French inventor, had created the Praxinoscope, an improvement of the Zoetrope. The Praxinoscope replaced the narrow viewing slits of the Zoetrope with an inner circle of 12 mirrors (equal to the number of images), allowing a clearer and less distorted view of the moving image. Several people could watch the performance at the same time. After Reynaud licensed his invention in 1877, it sold well in a number of the large Paris department stores.

In 1878 Reynaud produced the Praxinoscope Theatre. This improved version included a glass viewing screen which allowed the moving image to be superimposed over a changeable background. He continued to improve the design and in 1880 created the first projection version. The Projection Praxinoscope used a lantern to project the moving images onto a small screen, allowing a larger audience to view it, but was still limited to 12 images.



Poster advertising Reynard's first Théâtre Optique show

In 1888, he perfected a large scale projection version, that was similar in design to the projectors that would be used for cinema projection a few years later. Glass plates, individually painted by Reynaud himself, were mounted in leather bands. Each of the bands were connected by a metal strip with a hole through it which allowed it to locate on a pin on the rotating drum and align the image with the projecting lantern. By mounting the connected image strips on a pair of wheels similar to modern film reels, Reynaud was able to create a continuous series of moving images rather than restricting himself to 12 images, as had been the limit previously.


Pauvre Pierrot (1892) On 28 October 1892 he gave the first public performance of a moving picture show at the Musée Grévin in Paris. The show, billed as Pantomimes Lumineuses, included three cartoons, Pauvre Pierrot, Un bon bock, and Le Clown et ses chiens, each consisting of 500 to 600 individually painted images and lasting about 15 minutes. Reynaud acted as the projectionist and the show was accompanied by a piano player. Although the films shown by the Lumière Brothers in 1895 eclipsed it, the show stayed at the Musée Grévin until 1900 by which time over 500,000 people had seen it.

difference between a praxinoscope and a zoetrope

kinetiscope

A kinetiscope is a device which allows people to view motion pictures. The kinetiscope was one of the first such devices widely developed and distributed, and while the design ultimately proved to be a failure, it clearly inspired other inventors, so it could be considered a landmark invention in the history of film. This device was invented in the laboratory of Thomas Edison, and as was conventional for inventions in his lab, the patent was taken out by Edison himself, making it challenging to determine precisely who worked on the project.

The design for the kinetiscope consisted of a closed cabinet in which the film was spooled. To operate the device, the user opened the top and peered through a small hole, and as the film was moved across a series of rollers, a back light would illuminate it, creating the illusion of a moving picture, as long as the film was rotated at the proper speed. When the kinetiscope was first shown to the public in 1894, it proved to be a big hit.

Kinetiscopes began to spring up all over the United States, commonly being found in kinetiscope parlors, which featured a row of the devices which users could operate by inserting coins into slots. In addition to short films, the kinetiscope was also used to display footage of things like sports matches, allowing people all over the United States to see events which they had not been able to attend.

kinematoscope 1861

The Kinematoscope (a.k.a. Motoscope) was patented in 1861 (United States Patent 31357), a protean development in the history of cinema. The invention aimed to present the illusion of motion.

The patent was filed by Coleman Sellers of Philadelphia, Pennsylvania as an "improvement in exhibiting stereoscopic pictures". Coleman applied stereoscopy to the existing principle of toy phantasmascopes using rotating discs.

A series of still stereographic images with chronologically successive stages of action were mounted on blades of a spinning paddle and viewed through slits. The slits passed under a stereoscopic viewer. The pictures were visible within a cabinet, and were not projected onto a screen.

early days of animation

zoetrope and spindle viewer drawings

zoetrope

Who invented the zoetrope and when?

William Horner invented the zoetrope in 1834 in England. He called it the ‘daedalum’ (the wheel of the devil). It didn’t become popular until the 1860’s when the makers in both England and America patented it. The American developer William F. Lincoln named his toy the ‘zoetrope’, which means ‘wheel of life’

 

William Horner                William F. Lincoln

 

What did the zoetrope do/how did it work?

The zoetrope worked on the same principles as the phenakistiscope, but the pictures were drawn on a strip which could be set around the bottom third of a metal drum. The drum was mounted on a spindle so that it could be spun, and viewers looking through the slits would see the cartoon strip from a moving image. The faster the drum is spun, the smoother the image that is produced.