OPTICAL PRINTERS, MATTES AND THE Z FILM

[Chris Bristow]

I would like to start with some questions about using separate mattes for the limo movement and the background movement(camera panning) in order to remove a limo stop. The only way we know the limos speed or lack of it is the how the background moves by. So by altering the speed of the background with a separate matte for the background and the limo you could remove the limo stop all together. Here is a list of problems that would need to be addresses to accomplish such an edit.
1. If the limo completely stopped for 2 seconds there would 36 frames that have to be completely removed(This is assuming Zapruder would stop panning and stay fixed on the limo which would stop the background from moving across the frame). If the printer was capable of frame by frame compositing then you would stop the process and do a fast forward through the background  that was not moving then restart the process of compositing the 2 mattes into one film after forwarding past the background stop. Maybe those stopped frames would be removed on the background copy before combining the two elements in the printer. Does anyone know the method that would be used with an optical printer?
2. Would it be more difficult to handle the slowing of the limo to a stop and the acceleration from the stop than just taking out the fully stopped frames? Lets say the limo slowed very quickly from 8 mph to 4 mph in a single frame(Maybe not possible but it simplifies this thought experiment). You could take out every other frame starting at the 4mph transition frame and the limo would double it speed and continue at what looked like 8 mph. That works out fine. But what if the limo slows from 8 to 4 mph for 9 frames before changing speed again? Now I have to double the speed but I don't have an even number of frames. How do I remove half of 9 frames? I can't just run one of the mattes a little faster because the film is just a series of single photos strung together. Each frame of the mattes has to be married to another single frame.  Even a single extra frame would cause a momentary jerk of the motion. How would the edit be accomplished?
3. I have seen theories in which the limo movement was re timed from a point well before the slowing or stopping like when it was behind the Stemmons or just after. Would changing more of the limos timing down Elm help in dealing with the limo stop?
If it was re timed that early it also presents some new problems that more mattes may have fixed. A big problem is the reflections from the limo's trunk show Brehm and a  very tiny and distorted but identifiable para-style behind him. It later shows Mary Ann Moorman and Jean Hill and the same para-style around them. Altering the limo's position on Elm more than maybe 4 feet would create a big mismatch of the trunk reflections. Would that require another matte for the trunk?
changing the limos position on Elm would also create incorrect lines of sight through the limo like where the rear handholds on the trunk line up next to JFK, Jackie and the side windows too. Rotating the image of the limo in the matte can give the impression that the limos was facing the correct direction as you look at it's angle down Elm. But the rotation will not correct the lines of sight through the limo. If a rear handhold is sticking of out of JFK's ear rotating the image will not change those relative positions of JFK to the handhold.
 

[Chris Bristow]

 Below is a crop of fr359 and a blurry image that looks like a blue arrow or wedge icon. It is just to the left of the comp icon I inserted. It looks like it has a white border around it. The question is do modern optical printers place icons on the screen that do not appear in the final product?

Note; after posting the image it looks much worse than on my PC.

 

Edited September 7, 2021 by Chris Bristow

[Eddy Bainbridge]

Hi Chris, you are proposing, what appears to me at least, a complex process. I beleive there has been frame removal, I doubt 36 frames. I think Chris Davidson's work suggests less frames. Around extant Z313 frame removal is aided by the fact the camera direction forms approximately a 90 degree angle with the limo direction, and we highly suspect a slowing of the vehicle that has been removed. My wild estimate is around 18 frames that have not all been removed in a sequence. They have been removed to hide a hard braking, a pause,a second frontal head shot a rapid acceleration (at least more rapid then we now see).

In my view the use of a matte to cover the rear headwound is pursuasive, and is seen before the wound is actualy produced. I'm not pursuaded by the use of any other mattes, thus far.

[Chris Bristow]

12 hours ago, Eddy Bainbridge said:

Hi Chris, you are proposing, what appears to me at least, a complex process. I beleive there has been frame removal, I doubt 36 frames. I think Chris Davidson's work suggests less frames. Around extant Z313 frame removal is aided by the fact the camera direction forms approximately a 90 degree angle with the limo direction, and we highly suspect a slowing of the vehicle that has been removed. My wild estimate is around 18 frames that have not all been removed in a sequence. They have been removed to hide a hard braking, a pause,a second frontal head shot a rapid acceleration (at least more rapid then we now see).

In my view the use of a matte to cover the rear headwound is pursuasive, and is seen before the wound is actualy produced. I'm not pursuaded by the use of any other mattes, thus far.

I am not attempting to be an advocate or a critic for the process just wondering how it could have been achieved. I used 36 frames simply because I am assuming a 2 second stop for the sake of argument. It is one of those unknowns that make it hard to create a model. Many witnesses said 'The limo stopped or almost stopped' it makes me think it may have just slowed to such a crawl that it was hard for people to quickly assess whether it fully stopped.
 I like the matte theory but am not sure just how complicated it might get.