Thread 12—Don't analyze Z-film objectively

Thread 12—Don’t analyze Z-film objectively

 

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M

Don’t analyze Z-film objectively.

      The single message in Thread 12 really bothered me, in a way that many of the other messages here didn’t. I think it’s because this one was at once so blatantly antiintellectual and nonsensical as to hearken back to the dark ages before science:

A: [Quote from outside this discussion] The problem with this is that the "obvious" movement isn't nearly as high in magnitude as it would appear from the Z-film. Both Art Snyder and J, independently from each other, have demonstrated that blurring during the 312-314 sequence makes the backward movement seem much greater [ SNIP]

Hi A, When the head-shot strikes, the president’s upper body is thrust backwards as far as possible against the car seat, and then rebounds sharply in the opposite direction. I’d caution against trying to over-interpret the photographic evidence with frame by frame analysis and “objective” measurements. The human visual system is remarkably adapted to accurately interpret natural images. Our understanding of how it does this is rudimentary at best. If you want to understand the Zapruder film, watch it in slow motion a couple of times - you really can’t do better than that.

Edwin Land was a pioneer in the study of the human visual system. invented both the “retinex” theory of color vision and the Land camera. He was fascinated by the stability and reliability of our peception of color in the face of multiple fluctuating light sources. He gained insight into how this works with a series of carefully devised experiments in which he recorded people’s subjective color sensations under laboratory conditions in which he could precisely control and measure the wavelengths of the light that reached their eyes. Sometimes the subjects would ask him how they did - what the colors “really” were. His standard answer was, “the color was whatever you thought that it was - you have the world’s most sophisticated vision system inside your head - these banks of sensors and processors are extremely primitive by comparison”.

      The antiintellectual parts are mostly in M’s first paragraph, where he actually urged A to avoid the most revealing frame-by-frame measurements because they are “objective.” After all, M said, the human eye can do better than that with these “natural images.” Play it a couple times in slow motion and let it go at that. M all but called people who strive for objectivity “pointy-headed intellectuals.”
     
M made my point when he described JFK’s motion after the head hit as “being thrust backwards as far as possible against the car seat, then rebounding.” Since he never watched the film frame by frame, he was unaware that the backward thrust was actually the third motion—it was preceded by a quick snap forward and a quick snap backward. Only then did M’s large-scale backward motion begin, and it eventually accelerated rearward as gravity kicked in. But M didn’t want to know these things because they evidently didn’t qualify as “natural motions.” I suppose that M would also have us avoid using a telescope to observe the moons of Jupiter because the human eye isn’t adapted to see these “unnatural motions.”
     
M’s nonsensical points appeared mostly in his second paragraph, where he carried on about colors being whatever we think they are, a legitimate topic in its own right but utterly unrelated to JFK and the Zapruder film. The only possible connection could be the quote from Edwin Land in the last part of the last sentence, to the effect that our head contains “the world’s most sophisticated vision system.” But even this connection is a stretch that I consider unjustified. I guess everybody else did, too, for no one answered.

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