Re: how much of what we see is black?

From: Jonathan Walley (email suppressed)
Date: Wed Oct 31 2007 - 05:39:25 PDT

I haven't had espresso (or expresso, as we say in the midwest), only a
slimfast shake, but here goes:

> On Oct 30, 2007, at 1:59 PM, Todd Eacrett wrote:The myth of
> persistence of vision was first debunked 30 years ago:
> Then explain to me the multiple examples of persistence of vision (or
> retinal burn, or flicker fusion, or... ?) demonstrated in Werner
> Nekes' "Film Before Film."

I haven't re-read the essay recently, but I think the "debunking" is of
the belief that persistence of vision is what produces the illusion of
movement in film, and/or the illusion of continuous light. Do the
authors actually say persistence of vision doesn't exist? Nobody is
saying that we don't see afterimages, only that these afterimages
cannot account for what we see when we watch a film. Flicker fusion,
that is, isn't caused by the image of "Frame 1" remaining on our
retinas long enough to be superimposed with "Frame 2," but by something
else. I know "something else" is vague, but my understanding is that it
has more to do with the brain's interpretations of light impulses than
with the physiology of the retina. Cognitive rather than physiological,
I guess.

> BTW, perusing the link you provided suggests to me little more than
> that the term "persistence of vision" is "inaccurate and inadequate."
> As an example of verbal shorthand, the term can be quite appropriate
> because, conceptually, the conjoined words makes sense (are even
> poetic in their implications), regardless of the scientific accuracy
> of the phrase. There are many examples of such shorthand expressions
> that abet communication among non-specialists. As a scientific
> explanation it probably is inaccurate and inadequate. But then I don't
> watch or discuss films (or videos) in labs or morgues.

Some people are interested in scientific accuracy, others in
explanations that are more "poetic." As a heuristic, "persistence of
vision" might be useful, but I don't think that warrants consigning
other types of explanations, particularly ones that aim at greater
accuracy, to the morgue.

> The real purpose of this article seems as much "political" as it is
> "scientific":
> "Not only must the mechanism of persistence of vision that purported
> to explain the illusion of motion be replaced by an accurate
> description of the illusion, but the concept of a passive viewer
> implied by the myth must be replaced by the viewer implied by an
> enlightened understanding of the illusion: a meaning-seeking creature
> who engages the film as actively as he engages the real world about
> him.  To reject the mechanism of persistence of vision is to reject
> the myth of persistence of vision and the passivity of the viewer it
> implies."
> To be forthright, I find their assertion that using the term
> persistence of vision automatically assigns a passive role to the
> viewer to be pretty effin dogmatic and I'm going to file the above
> paragraph away with the writings of Christian Metz (in the dustbin,
> where all "presupposing" theories belong).

I agree that the authors may have been trying to hitch their little
perceptual wagon to the big star of Grand Theory debates in film
studies. Still, I take their point to be that, as it is used (e.g. in
many film studies and production classes), the concept of "persistence
of vision" parallels the assumption in psychoanalytic film theory that
the viewer is passive. I don't take them as saying that everyone who
uses the term necessarily has that assumption, just that the two ideas
- persistence of vision and viewer passivity - line up with each other
in a general sense.

> On Oct 30, 2007, at 3:04 PM, Jonathan Walley wrote:Both essays
> demonstrate - pretty convincingly, I think - that persistence of
> vision cannot account for the appearance of continuous light in film.
>> It's important not to conflate two illusions: the illusion of a
>> consistent light source when it is in fact flickering (I understand
>> this illusion to be called "critical flicker fusion"), and the
>> illusion of movement on the screen, which I refer to as "apparent
>> motion" when I teach it - I've heard people call it the "phi
>> phenomenon," but this names a different kind of illusory motion
>> perception than the one produced by tiny increments of change in
>> "normal" cinema, which produces the illusion, for instance, of
>> someone walking from one end of the frame to another.
> This kind of explanation is a bit more comfortable for me than the
> "film v video" competition, AND it avoids the canary in the mineshaft
> quote of the Anderson's essay I chose to cite.



Jonathan Walley
Cinema Dept.
Denison University
email suppressed

> db
> (who had a four shot espresso this afternoon)
> __________________________________________________________________
> For info on FrameWorks, contact Pip Chodorov at <email suppressed>.

For info on FrameWorks, contact Pip Chodorov at <email suppressed>.