Talk:Beta movement

phi

I am baffled. How are phi and beta different? " an apparent movement caused by luminous impulses in sequence, (that is to say, it is lights going on and off at regular intervals), whereas the beta movement is an apparent movement caused by lights that do not move, but seem to" -- The first go on and off, but in the example of the red circles, aren't they also going on and off?211.225.33.104 (talk) 10:40, 4 June 2013 (UTC)

I agree this needs to be cleared up - I have worked in computer animation for 15 years, understand English perfectly, and still can't understand the difference, in fact I'm sure these two are the same, the only difference is that, at least in the example, PHI movement is construed by 'empty' space "moving", and beta is construed by the light itself "moving" - in both cases there are static lights that go on and off. It might be that our mind perceives the two movements in a different way, but that's beside the question.

81.198.216.220 (talk) 03:42, 12 August 2013 (UTC)

Agreed, I wrote the same in the Talk page for Phi phenomenon: the supposed "difference" is actually the same thing stated with slightly different words. Can someone who actually understands both phenomena explain the difference? 200.0.230.234 (talk) 12:03, 2 October 2013 (UTC)

Discussion of beta movement in relation to film may suffer from semantics/splitting hairs

I think that the current discussion of beta movement in relation to film may suffer from semantics/splitting hairs.

First, I am referring to the second paragraph of the current Wikipedia article: "The illusion of motion caused by animation and film is sometimes believed to rely on beta movement, as an alternative to the older explanation known as persistence of vision. However, there are notable differences between the short-range apparent motion that occurs in film (with little differences between successive images) and the long-range apparent motion originally described as beta movement (with bigger differences between positions of successive images).[1]"

Second, I am referrring to the first sentence from the Confusion about phi phenomenon and beta movement section of the current Wikipedia article: "Wertheimer's pure phi phenomenon and beta movement are often confused in explanations of film and animation, but they are quite different perceptually and neither really explains the short-range apparent motion seen in film.[1]"

Although it is true that phi phenomenon and beta movement are often confused (and the subsequent distinction between the two that is provided is sufficient), in both instances in making the case that beta movement is notably different from or does not really explain the apparent motion seen in film, I believe that this is more about semantics/splitting hairs than it is a truly adequate argument against film not being an example of beta movement in principle. For both quoted statements above, the following article is currently cited: [1] Anderson, Joseph; Anderson, Barbara (1993). "The Myth of Persistence of Vision Revisited". Journal of Film and Video. 45 (1): 3–12.

In reading the cited article[1], however, it states the following on page 6: "In a series of experiments, Wertheimer isolated what he considered three primary stages of apparent motion: (1) beta movement (the object at A seen as moving across the intervening space to position B)..."

The cited article[1] also states the following on page 10: "The changes from frame to frame in live-action cinematography are small--not an instance of experimental apparent motion as it is usually presented."

Thus, according to the cited article itself[1], the frame-to-frame changes in film that give the perception of apparent motion essentially fit the definition of beta movement but differ in that the frame-to-frame positions of the objects in film are small compared to "experimental apparent motion [e.g., beta movement] as it is usually presented" (such as relative to Wertheimer's original experiments related to phi phenomenon and beta movement that he conducted in 1912). This seems to be a matter of a quantitative difference (i.e., Wertheimer having used larger spaces between the successive positions of objects in his original experiments) rather than a qualitative difference (i.e., apparent motion in film not really being an example of beta movement in principle/by definition).

I recommend that the information contrary to film potentially being an example of beta movement either be removed or be reworded in order to loosen the language, which if reworded, would be done in such a manner that clearly conveys that one perspective on film (i.e., film being an example of beta movement) is being opposed by another perspective on film (i.e., that the short-range apparent motion in film should not be considered beta movement due to the original or typical experiments with beta movement involving more space between the successive positions of an object), rather than making it seem as the Wikipedia article currently does that it is a matter of fact that film is not an example of beta movement. Criado Fiel (talk) 21:43, 9 February 2024 (UTC)

The more important conclusion of the Andersons:

"The human visual system can (and does) distinguish between long-range and short-range apparent motion, but it seemingly cannot distinguish between short-range apparent motion and real motion. To the visual system, the motion in a motion picture is real motion."

Their article cites plenty of academic research papers indicating that the neurological process for long-range apparent motion (as in beta movement) is entirely different from that for the close-spaced stimuli of motion in film (indistinguishable from real motion). Isn't that beyond hair-splitting?

I changed the lines on the page to better reflect the neurological aspect, rather than just the distance between stimuli.

It would be interesting to see other reliable sources supporting different explanations for the motion illusion of film. Are there any scholars who have investigated the relevant visual processes and have concluded that the apparent motion of film can be explained as beta movement? Or could it be that only people in film studies have come up with that theory and never backed it up with proper research? Joortje1 (talk) 05:54, 10 February 2024 (UTC)

Thank you for your response. After doing additional literature review, it does appear that vision researchers have tended to maintain the distinction between beta movement as being an example of long-range apparent motion versus the apparent motion involved in film (in most cases) being an example of short-range apparent motion.

My point was that, based on the definition of beta movement offered in the Andersons' article (i.e., beta movement, "the object at A seen as moving across the intervening space to position B"), an "intervening space" could be exceedingly small, as is the case with objects depicted by a rapid series of still images constituting a film. Thus, apparent motion in film potentially could still be explained/described as beta movement if the "intervening space" could vary to the point of being extremely small.

However, what I did not properly understand is with beta movement as originally specified by Wertheimer, he more specifically was referring to apparent motion that was produced by still images presented in succession which necessarily used wider "intervening spaces" between objects than would normally be used across frames in cinematography (which as has been noted, more closely mimics the perception of a visual scene in real life). Criado Fiel (talk) 21:40, 10 February 2024 (UTC)

I think I understand your point, but to me it seems like you're turning the problem into something like Zeno's paradoxes. You seem to want to turn the amount of intervening space that defines one variation of a motion illusion so small that it becomes another variation, while there are very good reasons to make a distinction between the two.

Walking and running are basically the same sort of action at different speeds, but the physiological aspects vary enough to realise that they affect the body in very different ways. In a similar fashion it makes more sense to treat short-range and long-range apparent motion as very different things.

The most striking finding in Wertheimer's 1912 publication was the difference between illusions with relatively slow tachistoscope frequencies (later dubbed beta movement) and the seemingly objectless motion seen at very high frequencies (the pure phi phenomenon). The latter was deemed much more interesting than the possible significance of beta movement in film theory.

Wertheimer and his colleagues may have drawn some comparisons with film and the relatively smooth animation at certain frequencies (it may be interesting to look up their exact quotes on this), but their conclusions probably were very nuanced and more complicated than just saying the illusion of film would be a form of beta movement; the experiments started further research into the complex ways in which the whole of visual configurations get processed rather than just the individual elements (see: Gestalt psychology). Joortje1 (talk) 07:09, 11 February 2024 (UTC)