Zapruder's Jiggles -- Did Marilyn Sitzman have a bad case of the hiccups?

[Tom Graves]

Did Marilyn Sitzman have a case of the hiccups?

Given the fact that Oswald's first, missing-everything, shot was at hypothetical Z-124 (half-a-second before Zapruder resumed filming -- after a 17-second pause -- at Z-133), how are we to explain Zapruder's camera's jiggling all over the place other than the possibility that the gal who was holding onto vertigo-plagued Zapruder, Marilyn Sitzman, had a real bad case of the hiccups?

If so, were they so loud that they caused some witnesses to believe that the shots were coming from the bushes?

[Duncan MacRae]

Did Marilyn Sitzman have a case of the hiccups?

Given the fact that Oswald's first, missing-everything, shot was at hypothetical Z-124 (half-a-second before Zapruder resumed filming -- after a 17-second pause -- at Z-133), how are we to explain Zapruder's camera's jiggling all over the place other than the possibility that the gal who was holding onto vertigo-plagued Zapruder, Marilyn Sitzman, had a real bad case of the hiccups?

If so, were they so loud that they caused some witnesses to believe that the shots were coming from the bushes?

[John Corbett]

Did Marilyn Sitzman have a case of the hiccups?

Given the fact that Oswald's first, missing-everything, shot was at hypothetical Z-124 (half-a-second before Zapruder resumed filming -- after a 17-second pause -- at Z-133), how are we to explain Zapruder's camera's jiggling all over the place other than the possibility that the gal who was holding onto vertigo-plagued Zapruder, Marilyn Sitzman, had a real bad case of the hiccups?

If so, were they so loud that they caused some witnesses to believe that the shots were coming from the bushes?

It is not a given fact that the first shot was fired at virtual Z124. That is your conclusion and you are entitled to it just as I am entitled to my belief the shot was fired at actual Z148. Neither of us has proof positive of what we believe but I'm sure I feel as strongly about my scenario as you do of yours. We both can't be right but it's possible we could both be wrong.

[Tom Graves]

It is not a given fact that the first shot was fired at virtual Z124. That is your conclusion and you are entitled to it just as I am entitled to my belief the shot was fired at actual Z148. Neither of us has proof positive of what we believe but I'm sure I feel as strongly about my scenario as you do of yours. We both can't be right but it's possible we could both be wrong.

ME: Explain in 100 words or less how Roselle and Scearce determined that the first, missing everything, shot occurred about half-a-second before Zapruder resumed filming at Z-133.

Thought for 7s

GROK: Roselle and Scearce (2020) used human reaction-time science on the silent Zapruder film to time the first (missed) shot.

acsr.org

They distinguished fast involuntary startle reflexes (e.g., ~0.06–0.2 sec flinch) from slower voluntary “surprise” reactions (conscious head turns/looks to locate the sound source). Using brake perception-reaction time (PRT) models from traffic studies—adjusted for total surprise—they estimated median perception time to initiate voluntary movement at roughly 0.5–1+ sec (varying with expectancy).

https://d7922adf-f499-4a26-96d4-8ab2d521fa35.usrfiles.com/ugd/d7922a_e280e26982b44f2c97c6e6e27026e385.pdf

In early frames, they identified near-simultaneous voluntary reactions by 7 witnesses (JFK, Jackie, the Connallys, Kellerman, Hickey, Rosemary Willis) starting ~Z140–Z150 (e.g., rapid leftward head turns then right). Subtracting typical surprise PRT placed the gunshot sound ~½ sec earlier—at hypothetical Z-124, just before Zapruder restarted filming at Z-133 after his ~17-sec pause.

jfk-assassination.net

This fits eyewitness timing, earwitness patterns, and a pre-tree miss. (≈85 words)

. . . . . . . .

I know you love jiggles, John Corbett, so just for giggles I'd like to share with you what someone by the name of Herb Huskr just posted:

Three synchronized film clips:

1) Elsie Dorman

2) Secret Service reenactment

3) Zapruder clip

Shown with three dubbed-in gunshot sounds at the following times in the three different montages:

Montage 1:  "Z-107" Z-219 and Z-310

Montage 2:  "Z-124" Z-219 and Z-310

Montage 3: Z-160 Z-219 and Z-310

When we watch and listen to montage 2, we see that Dorman, who at a distance of 35 feet was subjected to about 135 dB from the muzzle blast of Oswald's Carcano (whereas Zapruder, at 275 feet, was subjected to only about 119 dB, and Phil Willis at 130 feet was subjected to about 125 dB), was so startled by the sound of the first shot at "Z-124" that she stopped filming altogether (her finger slipped off the button). Then she resumed filming a couple of seconds later and at approximately Z-222 jiggled her camera like all get out and stopped filming again. Interestingly, she doesn't jiggle her camera at right after the Z-313 head shot. Could it be due to her having become habituated to the nearby muzzle blasts? Seems logical to me.


The Three Montages:

https://www.facebook.com/groups/553546571932211/user/100003268844965

[John Corbett]

ME: Explain in 100 words or less how Roselle and Scearce determined that the first, missing everything, shot occurred about half-a-second before Zapruder resumed filming at Z-133.

Thought for 7s

GROK: Roselle and Scearce (2020) used human reaction-time science on the silent Zapruder film to time the first (missed) shot.

acsr.org

They distinguished fast involuntary startle reflexes (e.g., ~0.06–0.2 sec flinch) from slower voluntary “surprise” reactions (conscious head turns/looks to locate the sound source). Using brake perception-reaction time (PRT) models from traffic studies—adjusted for total surprise—they estimated median perception time to initiate voluntary movement at roughly 0.5–1+ sec (varying with expectancy).

https://d7922adf-f499-4a26-96d4-8ab2d521fa35.usrfiles.com/ugd/d7922a_e280e26982b44f2c97c6e6e27026e385.pdf

In early frames, they identified near-simultaneous voluntary reactions by 7 witnesses (JFK, Jackie, the Connallys, Kellerman, Hickey, Rosemary Willis) starting ~Z140–Z150 (e.g., rapid leftward head turns then right). Subtracting typical surprise PRT placed the gunshot sound ~½ sec earlier—at hypothetical Z-124, just before Zapruder restarted filming at Z-133 after his ~17-sec pause.

jfk-assassination.net

This fits eyewitness timing, earwitness patterns, and a pre-tree miss. (≈85 words)

This reminds me of the so called acoustics experts who convinced the HSCA that there was a second gunman and a fourth shot. Their findings were never peer reviewed. Has anybody peer reviewed this study.

. . . . . . . .

I know you love jiggles, John Corbett, so just for giggles I'd like to share with you what someone by the name of Herb Huskr just posted:

Three synchronized film clips:

1) Elsie Dorman

2) Secret Service reenactment

3) Zapruder clip

Shown with three dubbed-in gunshot sounds at the following times in the three different montages:

Montage 1:  "Z-107" Z-219 and Z-310

Montage 2:  "Z-124" Z-219 and Z-310

Montage 3: Z-160 Z-219 and Z-310

When we watch and listen to montage 2, we see that Dorman, who at a distance of 35 feet was subjected to about 135 dB from the muzzle blast of Oswald's Carcano (whereas Zapruder, at 275 feet, was subjected to only about 119 dB, and Phil Willis at 130 feet was subjected to about 125 dB), was so startled by the sound of the first shot at "Z-124" that she stopped filming altogether (her finger slipped off the button). Then she resumed filming a couple of seconds later and at approximately Z-222 jiggled her camera like all get out and stopped filming again. Interestingly, she doesn't jiggle her camera at right after the Z-313 head shot. Could it be due to her having become habituated to the nearby muzzle blasts? Seems logical to me.

Apparently Zapruder hadn't become habituated to the muzzle blasts.