Jump to content

Talk:Persistence of vision

Page contents not supported in other languages.
From Wikipedia, the free encyclopedia

Article

[edit]

How have psychologists and physiologists rejected its significance? Do you mean that they have shown the phenomenon doesn't exist? Don't we in any case need an explanation for why we perceive things the way we do? I'm confused. Vivacissamamente 04:52, 31 October 2005 (UTC).[reply]

This needs lots more work. We need to distinguish more clearly between flicker fusion and the illusion of flow, and discuss temporal aliasing a lot more. -- The Anome 09:46 7 Jun 2003 (UTC)

In respect of this note, I have tried to sort out a few issues here but the fact remains that neither persistence of vision not phi phenomena explain how human being perceive apparent motion (or any kind of motion for that matter). The issues involved here are the fact that there is a threshold of vision where really fast moving objects (airplane propellers for example) are not perceived at all. Thus the blinking of the eye is simply not perceived, and you don't need a theory to explain the absence of a blackout in terms of an afterimages being held on the retina. A plausible explanation for humans seeing apparent movement is that in nature, things do not disappear and reappear in another place. However, some things like predators do move really fast, so the eye (or rather the brain) has evolve to perceive things that jump from one position to another as moving at speeds above the threshold of vision..... Whether an entry on persistence of vision should strive to explain the perception of motion is another matter. I'm not sure what articles that are better placed in an entry on flicker-fusion are doing in an entry on persistence of vision. Furthermore, I'm not really sure what the passage on LED monitors is trying to say. In respect of screen flicker (or no screen flicker), the fact remains that all moving pictures are constructed out of still frames whether the medium is flick-books, strips of film or Quicktime video and other digital formats on LED monitors. At its heart there is a troubling contradiction in this article. There are those contributors (like me) who are at pains to point out that the original persistence of vision theory does not explain apparent motion and there are others who seem to want to use this article to serve as validation for this theory. what is needed is for someone to sort out the mess--Rodmunday (talk) 08:23, 8 June 2009 (UTC)[reply]

"Persistence of vision was based on the assumption that biochemical transmission of nerve responses hysteresis is much slower than the light transmission." I have removed the this sentence. The claim seems to presuppose that we can perceive light through in some immediate way that does not involve 'nerve responses' which is nonsense. Therefore the fact that light travels faster than the biochemical nerve responses is irrelevant.--Rodmunday (talk) 08:23, 8 June 2009 (UTC)[reply]

cartoons

[edit]

someone might want to mention in the animation section that some cartoons simulate motion blur in the drawings, because you can't actually get that in 2-D animation. (might be easier to mimick now w/ CGI cartoons and stop-motion animation, but in the old fashioned animation they had to actually draw the blur into the actions)

Blinking LED

[edit]

A fast bliking LED will produce a snow flake, plaid or Persian rug like pattern in the eye, especially with the eye closed and the light passing through the eyelid. Which theory dose this support? Is this the scan pattern of the eye? Is the pattern the same in eveyone or not? It is said that some people have trouble reading due to the letters blurring and changing color as they are scanned.

  • I don't think this has anything to do with persistence, but I may be wrong. I had an impulse to remove that section from the article, but I'll leve that to others... --Janke | Talk 08:11, 29 November 2005 (UTC)[reply]
I went ahead and removed the LED section. We need a reference that proves it belongs here. --Janke | Talk 11:08, 1 January 2006 (UTC)[reply]

Persistence of Vision as a myth.

[edit]

How should http://www.uca.edu/org/ccsmi/ccsmi/classicwork/Myth%20Revisited.htm affect the article? Should "Persistence of vision" be categorized as pseudoscience? [http://en.wikipedia.org/w/index.php?title=Talk:Persistence_of_vision&action=edit Editing Talk:Persistence of vision - Wikipedia, the free encyclopedia[User:Hackwrench|Hackwrench]] 21:41, 29 May 2006 (UTC)

Interesting... As the wiki article says, there is a division among scientists and film scholars. I have inserted a note about it being considered a "myth". --Janke | Talk 07:00, 30 May 2006 (UTC)[reply]

Talk of pseudoscience is besides the point, the persistence of vision is a theory that has been called into question that's all. Theories are only useful to the extent which they can accurately predict and explain phenomena. Examining the usefulness (or otherwise) of theories part of the systematic approach that can be said to be characteristic of both good natural sciences and good film criticism. --Rodmunday (talk) 17:21, 2 July 2010 (UTC)[reply]

I'm sorry if this is harsh, but I just gotta say it: I find it mildly amusing that a little bit of insight into neurology and physics could have prevented this entire doomed branch of film theory from ever having sprouted (well, continued anyway). It might as well be astrology. So, yes, I guess you could say persistence of vision is pseudoscience (even though it's a pretty harmless phrase), but the Andersons' paper is full of a whole bunch of unnecessary (at best) or irrelevant (at worst) counter-argument. Skip the psych experiments and just extend the concepts of high school science. For example, what the Andersons' (and others) refer to as "real motion" doesn't even exist. All motion is merely "apparent". How could it be any other way, given that your eyes are connected to your brain by neurons, which are discrete conductors of information (see Refractory_period#Neurology_refractory_period)? On top of that, the photons hitting the retinas are discrete, whether they're coming from a movie screen or your hand waving in front of you. There's nothing essentially different about seeing pictures as moving and seeing "real objects" as moving. If what you're really interested in is what the thresholds for perceiving motion are, then study psychophysics. Otherwise, you're attempting to answer the binding problem. --MilFlyboy 02:52, 1 October 2007 (UTC)[reply]

If persistence of vision is a myth in regards to our perception of motion, why does the rest of the article go on to refer to film, video, and animation? If the theory is not applicable, shouldn't these sections be stricken from the article entirely? Persistence of vision doesn't really apply to these areas at all. 209.6.170.107 (talk) 23:49, 23 September 2008 (UTC)[reply]

You have a very good point! Persistence of vision is such a commonly encountered theory in film literature that is needs to be actively 'debunked.' The motion of animation and film can be explained by phi phenomen & beta movement. Whether these items should be moved to the relevant is indeed moot! --Rodmunday (talk) 15:45, 26 July 2009 (UTC)[reply]

Some of the above conflates 2 independent concepts: (1) does POV have anything to do with how we percieve a motion picture (2) is POV of the eye a real physical phenomenon. The former question is outside my expertise. the latter is absolutely yes. See: http://webvision.med.utah.edu/photo2.html --Dgold (talk) 08:51, 6 December 2009 (UTC)[reply]

PLEASE NOTE POSSIBLE INACCURACY HERE "Persistence of vision should be compared with the related phenomena of beta movement and phi movement. A critical part of understanding these visual perception phenomena is that the eye is not a camera: there is no "frame rate" or "scan rate" in the eye; instead, the eye/brain system has a combination of motion detectors, detail detectors and pattern detectors, of which each output is combined to create the visual experience. "

Actually recent research has shown that some kind of frame mechanism may exist in perception, as evidence by the fact that a great many people report seeing the wagon wheel illusion in real life. In a lecture I took, I polled a class of some 80 students and about half has reported seeing this effect. In one UK study (Purves, Paydarfar and Andrews 1996) researchers at the university of Durham set up a rotating wheel, viewed in continuous light by twelve subjects. Of the twelve, eleven reported seeing the wagon wheel illusion under these conditions. —Preceding unsigned comment added by Rodmunday (talkcontribs) 12:01, 7 June 2009 (UTC)[reply]

Eye is not a camera

[edit]

Well, it's not, but this: "the eye is not a camera: there is no "frame rate" or "scan rate" in the eye: instead, the eye/brain system has a combination of motion detectors, detail detectors and pattern detectors, the outputs of all of which are combined to create the visual experience." does not really work well. For one, it being a combination of such detectors does not necessarily mean it is not discrete. Something else should be used as justification for the non-discrete nature of the eye's processing than that. mike4ty4 08:46, 8 May 2007 (UTC)[reply]

IMO this should become 2 separated articles

[edit]

I believe there should be one article about whatever makes we see motion in sequences of images, and one article about the afterimage effect, with an disambibuation page for "persistence of vision" summing up the differences. --TiagoTiago (talk) 07:49, 16 December 2009 (UTC)[reply]

Lilac chaser

[edit]

The explanation for the lilac chaser is totally wrong. No dot is moving, just switched on/off. The green dot, not the absence of a dot (gray) is an illusion. Stop the animation (take a screen snapshot) and you'll see. --Janke | Talk 20:30, 16 October 2010 (UTC)[reply]

This article is nothing but confuse!

[edit]

I am doing some reasearch for my master degree in visual arts and my main field is moving images. I am writing an article for a neuroscience subject and I have to confess that this wikipedia article was the worst about the theme I found on the web. It says that "A more plausible theory to explain motion perception (at least on a descriptive level) are two distinct perceptual illusions: phi phenomenon and beta movement", but right after this it says "Persistence of vision is still the accepted term for this phenomenon in the realm of cinema history and theory"? How confuse that can be? Of course the article about the myth have some gaps, but seems that it was just ignored. The way persistence of vision is described here take for granted every consideration made by the authors on how pesistence of vision has nothing to do with aparent movement. We´re not at all just passive viewers.fabs (talk) 10:48, 11 February 2014 (UTC)[reply]

  • Well, people in the film and video industry have gotten used to the name "PofV", and don't know anything about phi and beta... so it's still an accepted term, even though the theories behind it may have changed. Since you're doing a thesis for your degree, this would be an excellent opportunity for you to improve Wikipedia, do your research, find sources, and improve this article. In fact, you could even add an appendix to your thesis, showing the "before" and "after"of this article"! Good luck with your research! --Janke | Talk 12:03, 11 February 2014 (UTC)[reply]

Cleanup needed - What Is PoV is Not

[edit]

If there is another article on wikipedia that explains how the different pyscological and optical tricks combine to create all the effects covered under the umbrella of "Pesistance of Vision", then this article should point to it.

Otherwise, this article should focus on those things rather than debunking some victorian oversimplification that should not be dignified with the term "theory" (seriously IS it a theory? Can you give me an example of a reputable source talking about the mechanism, or is it just a strawman)

This whole article needs a complete re-write, breaking down the optics and neuro-psychology of vision into proper sections, rather than just repeating "the eye does not retain images" over and over and over... — Preceding unsigned comment added by 81.104.141.51 (talk) 01:18, 15 June 2015 (UTC)[reply]

Babies and bath water

[edit]

C'mon, folks, as the result of a well-intentioned crusade against a misconception, this article has become a serious educational hazard to the unwary passing reader.

Does persistence of vision explain why movies seem to move? No, despite what they taught me in fourth grade, it is now evident that it does not, although in the case of intermittent-display systems (traditional film projection, CRT video displays) it does provide some assistance to the illusion by suppressing the perception of flicker.

Does persistence of vision exist? Cover your eyes with your hands, face something brightly lit, uncover your eyes as briefly as possible, then observe how the "snapshot" persists strongly for a small fraction of a second before rapidly fading away. Yes, Virginia, persistence of vision DOES exist.

It is an absurdity for any part of this article to question or deny the very existence of persistence of vision, and mind-boggling for it to declare in its lede, as it now does, "The causes of Persistence of Vision is a combination of the phi phenomenon, beta movement, and Flicker fusion..." (bad grammar and capitalizations sic) and, later, that "the theory of persistence of vision is the belief that human perception of motion (brain centered) is the result of persistence of vision (eye centered)", etc., etc. Is this wretched verbiage the work of juvenile animation geeks with conceptual tunnel vision? Won't someone who can discern one topic from another kindly sweep this article clean of such atrocities? 66.81.221.218 (talk) 19:36, 30 September 2015 (UTC)[reply]

How is this disproved by "phi phenomenon and beta movement" if beta movement by its description is literally caused by persistence of vision?

[edit]

In article Beta movement it reads "This optical illusion is caused by the fact that the human optic nerve responds to changes in light at about 10 cycles per second".

How is it different from "narrowly defined" "persistence of vision (eye centered)"? --fireattack (talk) 05:08, 14 September 2016 (UTC)[reply]

Iconic memory qualified as potential myth

[edit]

The section "Other theories for motion perception in film" reads: "Some scientists nowadays consider the entire theory of iconic memory a myth", and links to https://www.jstor.org/stable/20687993?seq=1#page_scan_tab_contents - however, the source doesn't mention iconic memory at all (at least, the one page preview available doesn't - the other preview pages don't work).

Additionally, the article on iconic memory - https://en.wikipedia.org/wiki/Iconic_memory - presents no such myth aspect.

It's very unfortunate that these articles are not consistent, but I don't know how to rectify it.