How long does it take to alter hundreds of frames of film?

[Ray Mitcham]

Another example of CTers entertaining multiple and sometimes mutually exclusive realities.  In some cases, they rely upon the Z-film as proof of a conspiracy (e.g. "back and to the the left").  In others, that the film is faked or altered to avoid showing evidence of a conspiracy.  The Alamo defense of all CTer claims ultimately boils down to suggesting that all evidence is faked or the product of intentional lies.  The Catch-22:  Any evidence of Oswald's guilt is suspect and dismissed for that reason alone.

Just tell us why the film we see is different to the one Rather saw.  (And don't say "prove they are different" because Rather saw the limo turn the corner into Elm Street,) or is he just mistaken, lying or crazy?

[Chris Davidson]

The only car close enough to the limo to fulfill Rather's description.

[Chris Davidson]

Except his reference is to the film he just watched, not what was viewed from where he was standing.

The white lead car most likely appeared in the same footage as the limo turn onto Elm St, which was eventually excised.

[Jack Trojan]

I already replied to this thread but it got wiped out by the LNers because I was getting too close to home.   

Chris Davidson is on the right track. There are only 2 questions needed to be answered to resolve this one:

1) Where is the "original" Z-film? Life got a COPY.
2) Why was the film "edited"?

There were at least 2 splices in the film, which the FBI must have created and they removed an entire section of the turn onto Elm. Zapruder said he never recalled letting his finger off the trigger at any time after he started filming. So why was this footage removed? And why are there splices in the film? And most importantly, where is the original film and why did the FBI keep it?

Any editing done to the film to remove contradictions to the LN scenario would have been done with an optical printer like they used for practically all movies at the time for FX. This would include:

1) Speeding the limo up by removing frames before and after the head shot. Easy peasy.
2) Blackening the back of JFK's head for a few dozen frames. Piece of cake.
3) Cut out the turn onto Elm where the limo barely navigated the turn. Just another splice, which they botched.

So to ans the OP of how long does it take to alter hundreds of frames of film is...a few hours max. Which is exactly what they did. Otherwise, why did they modify it at all?

[Joe Elliott]

Any editing done to the film to remove contradictions to the LN scenario would have been done with an optical printer like they used for practically all movies at the time for FX. This would include:

1) Speeding the limo up by removing frames before and after the head shot. Easy peasy.

Jack does not understand simple Physics.

The limousine can only slow down so much. It can only lose about 0.5 foot per second per frame.

So, a limousine is moving at 10 feet per second. It advances half a foot down the street from frame to frame.

Let?s take a theoretical example:

Frame 100: It starts to brake as much as possible
               ; I known, I chose 100 to make the math as simple as possible.
               ; And 20 Zapruder frames per second to, again, make the math as simple as possible.

Frames 100-120: It slows from 10 feet per second to zero feet per second.
               ; About half as fast as it could slow down (decelerate)

Frame 120: The limousine is stopped 5 feet further down the street from Frame 100.

Frames 120-140: Limousine stays stopped for one second.

Frames 140-160: Limousine accelerates back to 10 feet per second.

              ; The maximum acceleration would be something like this, at best.

Frame 160: The limousine is back at 10 feet per second, now 5 feet further down the street from Frame 120.


Remove frames 100 through 160? Removing the slowdown and stop? Easy peasy?

Except for one problem. The limousine would suddenly appear to leap 10 feet down the street between the now two consecutive frames.

And also, the problem that the occupants in the limousine, and the moving spectators, would also appear to suddenly move at an impossible speed.



If:

 limousines could suddenly start and stop. Accelerate and Decelerate at 6 G?s (as opposed to the more realistic 0.3 G?s)

and:

all people in the limousine and spectators froze and did not move a muscle while the limousine was stopped.

Then:

Yes, Jack?s method would work fine. There are no frames to remove during the deceleration and acceleration, because this was down instantly. Just remove the frames while the limousine was suddenly stopped. Easy peasy.

But this would not work in the real world.

[Bill Chapman]

1) How could Kennedy's hand be at the side of his head (as Rather reports) when I see both his hands rise up sharply from just below his chest as he emerges from behind the sign. Oh, wait... the Zfilm was faked. Right?

2) Did Connally say anything about being shot in the chest as he turned to the back (according to Rather) or did he say he felt like someone had punched him in the back?

[Jack Trojan]

Jack does not understand simple Physics.

I'm a physicist. 

The limousine can only slow down so much. It can only lose about 0.5 foot per second per frame.

snip..

Are you referring to the jump cut at the turn onto Elm? I agree that from all accounts the limo had to almost stop to navigate the turn, which is probably why it was cut wholesale from the film. Pls explain the splice at frames 154-158:




But I was referring to the head shot which is more complicated to speed the film up but easy peasy nonetheless. An optical printer can quickly decimate frames to smoothly speed up the limo enough to cover up a "near" stop. If you want to do this right you must redo your calculations to determine the frame frequency/de-acceleration and decimate frames accordingly.



Note that the "speed" of the limo is in photo-units. Track the rotation of the tires and their circumference for a photo-unit -> speed conversion. When I did this I found the limo slowed down to ~7 mph. Speeding up the limo any more than that would also speed up bystanders actions as well, which would raise suspicions. I am not convinced that the limo was sped up in the darkroom, but it certainly could have been done easy peasy. The real question is why did it slow down at all? And why did it slow down just before the head shot? It caused the trailing motorcycles to make complete stops and gave Clint Hill a chance to climb aboard.

Lastly, I have a problem with the following clip of frames 317 to 320:



This animated GIF is depicted in real time. All the motion seen in the limo happened in less than a blink of the eye (.17 secs). In particular, note how quickly William Greer turned face front after applying the breaks and looking back at JFK just before the head shot. Looks like it is missing a couple of frames to de-emphasize that Greer hit the brakes hard enough to throw Kellerman forward, almost into the dashboard.

Given the Z-film was clearly modified by the FBI and as far as anyone knows they still have the original film, how can anyone look at a copy of the Z-film and claim the original had not been altered?

[Chris Davidson]

Close to the 154-158 span

CE884 entries for Z161-z166

Using the lightpost and CRB corner from the extant Z background, plotting the limo via the WC final plat, the speed of the limo equals 13.44mph.

13.44 x 1.47(1mph) = 19.7568 ft per sec

19.7568 / 18.3fps = 1.0796 ft per frame

5 frames (z161-z166) x 1.0796 ft per frame = 5.4ft traveled

CE884 states .9ft traveled for 5 frames

6frames x .9ft (distance given for 5 frames traveled CE884) =5.4ft

CE884 distance reflects 1 frame traveled at .9ft with the distance of 5 frames traveling @ 13.44mph, missing.