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Fragment trajectories...


John Dolva
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If one accepts the sync of the Z and N as worked out in Nix topic, then one must accept that N23 came a very brief moment after Z313.

This helps to make a suggestion of the direction that the fragments took after leaving Kennedy's head.

Here's an attempt at understanding these trajectories.(updated image next post)

For both cameras to capture the fragments at almost exactly the same moment from almost directly opposit each other, but one considerably more elevated and closer, it seems to me that the fragments MUST travel south.

Any alternatives?

I can understand a reluctance to find that the trajectories are perpendicular to suggested shot trajectories, and they have covered this distance in less than 0.025 seconds, and therefore are likely to have a direct relationship to the direction the bullet came from, and not due to being propelled by the explosive cavitation. However, this is another issue that will not go away and needs a proper answer/understanding.

Edited by John Dolva
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Thanks to Don for base map

head 422,6

zcamera 435

ncamera 435

For those who are interested in checking for themselves here are some aids or suggestions of how to work it out (as I understand it.)

My findings are that the higher more visible fragment trajectory is a line that coincides almost exactly with a line from the collonade openings nine openings across from the western cupola.

EDIY::Forget about where you want the shot to be from. If someone presented you with the fragment trajectories (assuming theyre correct as worked out) where is it more likely the bullet came from?

Edited by John Dolva
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John, I'm very interested in this fragment trajectories analysis, but try as I might I can't seem to decipher your montage in this thread. Could you dumb it down a little and maybe take it in smaller, more incremental steps?

Ashton

OK, I was hoping by not detailing it someone might arrive at an alternative, or in working out what I've done, will pick mistakes. If you do what I have done I think you will simply arrive at the same result and that's fine but not as good as an independently developed answer.

What I've tried to do in that montage is to provide the necessary tools like rulers and models and a resizing of frames etc as best as I can. Any other attempt may find that useful.

Let me wait a while before detailing. Perhaps a hint. If the moments are near simultaneous, then the end of those trajectories inhabit the same area in 3D space, simply viewed from knowable points in space. The rest is just straight lines as light travels thus, and ...

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I'm still digesting this, too, Ashton. I do believe that understanding the fragment path is important to the overall understanding of the events. The problem is that we are dealing with three dimensions and a very short amount of time. Complicating matters is that our best view (the Z-film) is a 2-dimensional version of 3D events. The other 2D views available lack the detail of the Z-film. Further complication comes in the form of a moving limo...

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Guest Mark Valenti
I'm still digesting this, too, Ashton. I do believe that understanding the fragment path is important to the overall understanding of the events. The problem is that we are dealing with three dimensions and a very short amount of time. Complicating matters is that our best view (the Z-film) is a 2-dimensional version of 3D events. The other 2D views available lack the detail of the Z-film. Further complication comes in the form of a moving limo...

Frank,

Speaking of 3D, I was wondering if there might be a way to three-dimensionalize the Zfilm. This may be an extremely simplistic approach but I don't believe anyone has ever done it before and there may be some light shed on the movements.

Does anyone know of a simple software that can create a 3D effect? Not that I want to be seen looking at my computer monitor while wearing 3D glasses... :blink:

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I'm still digesting this, too, Ashton. I do believe that understanding the fragment path is important to the overall understanding of the events. The problem is that we are dealing with three dimensions and a very short amount of time. Complicating matters is that our best view (the Z-film) is a 2-dimensional version of 3D events. The other 2D views available lack the detail of the Z-film. Further complication comes in the form of a moving limo...

Frank,

Speaking of 3D, I was wondering if there might be a way to three-dimensionalize the Zfilm. This may be an extremely simplistic approach but I don't believe anyone has ever done it before and there may be some light shed on the movements.

Does anyone know of a simple software that can create a 3D effect? Not that I want to be seen looking at my computer monitor while wearing 3D glasses... :blink:

Mark,

The most common "3D" effect is an Anaglyph. This is the method that uses the good ol' Red/Blue (or Red/Cyan) glasses. Two images are filmed or photographed simultaneously with the lenses about as far apart as one's eyes. The images are filtered (different colors for left and right eye, essentially) and then combined into one image. The downside is a loss of some color, and typically brightness issues.

The result typically looks like:

There is a trick that can simulate the Anaglyph effect if the source is interlaced (such as an NTSC video camera). It involves creating the image pairs using the even and odd fields, applying the appropriate color mask, and the recombining the images together. The Z-source isn't originally interlaced, but the resulting DVDs and tapes are. I've made a version of the z-film using this method, but don't have any 3d glasses around to try it with... I have a few other ideas to try if this method doesn't work.

Of course, the original source was not filmed with 2 lenses, etc, so anything we do will produce a 3d effect, but the accuracy might be somewhat less than one would achieve from a true anaglyph source. Nevertheless, should be fun to try!

Now I just have to find some glasses. They are, of course, the kind of stupid things that I hang on to for years under the "I might use these some day" category, only to toss later during a cleaning spree... (This place has a "free pair" offer, but I imagine the arrival time would be quite slow: http://www.rainbowsymphony.com/free-3d-glasses.html

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John, I have no idea whether I've come even close to finding the Rosetta Stone to your inscrutable montage, but I thought, "What's he gonna' do—shoot me?" So I set up four colored "ping-pong balls" to represent the fragments in an approximation of your overhead view, all four balls at the same elevation:

fragmentsoverview.jpg

Then I went back and forth between the two film stills, and tried at least to approximate what you seemed to be suggesting with the different colors in terms both of spacial distance from the viewer, and height. I don't think I did it very well, but it was a painful operation with the strain on the inadequate processor in cycling back and forth between views, so for now there's a Quicktime movie attached of where I got to when I had to walk away from it.

Ashton

Edited by Ashton Gray
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Ashton, I think that will be an excellent way to eventually show the fragment paths. Good you have the growing expertise to do these views.

The overhead I made that shows the four dots are showing them as they are seen from Nix and Z's positions, not as they are in overhead. So I suppose they are a kind of visual question of where are they in 3D in order to be seen in these two different ways on the film frames. Think of the film frames as standing on edge. A line from Z through one dot and a line from N through the corresponding dot on the N frame intersects at the point they are in 3D. This explains the elevation view in the red box.

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Ashton, I think that will be an excellent way to eventually show the fragment paths. Good you have the growing expertise to do these views.

John, that was a very ambassadorial way you found to say, "Nice try, bonehead."

:blink:

I'll take another run at it when I get a chance after meditating on the elevation chart. (I mean literally: printing it out and using it as a mat.)

Ashton

P.S. Okay, just kidding about the chart thing.

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er..umm..well yes... but it did strike me as an excellent thing you're doing nevertheless.

I note you are getting the bodyposes of J and K in order. In time that would be an interesting view or fly over of the transition from 312 to 313. If we can settle on a matching M frame we can possibly triangulate the head positions.

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I note you are getting the bodyposes of J and K in order. In time that would be an interesting view or fly over of the transition from 312 to 313. If we can settle on a matching M frame we can possibly triangulate the head positions.

The person who was modeling some JFK and Jacquie articulated models and I have run into a technical problem with the limitations of Sketchup. So those 3D figures currently in the model all, of necessity, are still just the same stock sitting figure, just oriented differently. But there's no way to move the heads or limbs. I haven't given up on it, but so far there is no workaround in Sketchup itself, so options are being explored for now exporting the model to a more robust program on a machine with lots more horsepower. And that's going to entail its own learning curve (although I may be getting some help in that quarter, too.) As it is, things are at a crawl when working in the model unless many layers get turned off for every viewpoint move.

Of course this is all being done on a shoestring in spare time, too, so is having to advance when and as it can. Maybe it will all come together with the film sync project. I'm working on it.

Ashton

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  • 2 weeks later...

partial update

a few different views of the same model showing different directions and lengths of trajectories.

the base image of the analysis of N and Z views

perhaps it'll jog some thinking on how to derive a trajectory if one has three different views of the same trajectory

Edited by John Dolva
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This visualisation might help in understanding the issue.

Various views of the plane on which the trajectory must be.

The trajectory line in Z313 is the same one as in N23. The lines 'cast a shadow' or form a plane viewed edge on from N and Z.

These two planes intersect in a line.

So, it's not hard to understand that this line exists.

But, where is it.

Is it possible to work out matematically?

We have a location of origin. We have two points that this line is viewed from.

There are knowable elevations and angles.

It seems to me that some sort of formula can be created which will crunch this data and give a vector of the trajectory. What is this formula? Specifically what data needs to be known to put in this formula?

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crunched formula data = trajectory vector V (t)

(a distance measured on z313 between two points on this line d(z)) divided by (shutter speed of Z's camera C(z) ) = velocity of fragment v(f)

shutter speed of nix camera ( C(n) ) = d(n)/v(f)

(formula supplied by Ashton) >>> Nix camera frame rate etc etc etc...

__________________________

knowing Nix frame rate one can know syncs throughout the film. We can then step through the overlapping film frames of the films that sync is established and derive a continuous time line. Anomalies or provable significant deviations from this can pinpoint things such as missing frames. Reverse engineering or deconstructing those anomalies may reveal what is hidden.

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