The Amazing Bone Fragment in Z313

[Robert Prudhomme]

As we all know, two frames from the Zapruder film, z312 and z313, have been studied exhaustively over the years, since the film was first shown to the public in 1975. Both frames are shown below:

z312

z313

I was just watching a video by Josiah Thompson titled "The Untrue Fact about the JFK Assassination". In this video, Mr. Thompson pointed out a difference between z312 and z313 that I had not noticed before. If you look closely at the divider bar above the area between the front seats and the jump seats (occupied by the Connallys), you can see a number of reflections that show up as whitish dots in z312. However, in z313, these same "dots" appear as elongated objects. The reason is simple, as explained by Mr. Thompson.

The movie camera used by Abraham Zapruder was not, at 18.3 frames per second, considered anywhere even close to being a "high speed" or "stop action" camera, and any movement of the camera at all would result in blurred images being exposed on the frames. Mr. Thompson theorizes that the sound of the rifle shot at z313 might have startled Zapruder, with the resultant blur in z313. Or, alternatively, Zapruder simply could have made an involuntary movement that made the z313 blur. Whatever the case, the z313 frame is most definitely blurred, and this can be seen in things such as the faces of Connally or the SS men in the front seat, as well as in many details of the limo itself.

Just above the windshield of the limo, in z313, can be seen a white elongated blur, supposedly an empty film package dropped on the grass by either Altgens or the man with a camera beside Altgens. This object is much shorter by z315, indicating it too suffered from the blurring effect in z313, but I would really not like to use anything outside of the limo in this thread. As the limo was moving forward at 12 mph (17.4 feet per second), and as Zapruder was tracking the limo with his camera, we should expect stationary objects to have a blur to them.

However, there is one object that, right up to z312, was a part of one of the occupants of the limo, and only left the limo in z313. That object is the bone fragment seen ascending skywards from the top of JFK's head. As we are told by WC apologists, it can be seen toppling end over end as it flies upwards, and it actually appears to be four or five fragments, one above the other.

How does this jive with our explanation for the elongated blurs seen elsewhere on the limo? In actual fact, not at all.

As the fragment was, in z312, part of JFK's skull, and moving forward with the limo at 12 mph (17.4 ft./second), it should still retain the forward momentum (inertia) in z313, regardless of how fast it is ascending skyward. It is like standing in the aisle of a jetliner travelling at 500 mph. If you jump up in the air, or if you were able to hover above the aisle, you are still able to retain a forward speed of 500 mph, and to everyone else in the jet, you appear to remain stationary, even though at that point you would not be attached to the jetliner. Of course, though, if you were outside the jet, at 500 mph, you would soon get swept away by wind resistance, but our case, at 12 mph, is quite different. This case is much more analogous with the sailor being 60 feet above the deck in the crowsnest of a sailing ship moving through the water at 15 knots, and dropping a cannon ball from the crowsnest. The question is, where will the cannon ball land? The answer, of course, is at the foot of the mast, as the cannon ball retains the forward inertia and, instead of dropping straight down and landing behind the ship, it follows a forward angle downward.

Knowing these basics, the fragment(s) seen in z313 should have the same elongated horizontal blur as do many other parts of the limo, yet they do not. But that is not the only thing wrong here.

I'm not sure how fast the fragment seen leaving the top of JFK's head was travelling in the first few feet of its journey but, I am willing to bet it was a great deal faster than the limo was travelling. Having personally seen fragments fly from the skulls of deer that have been shot, I can attest that the movement in the first few feet is so fast, the human eye cannot follow it, while the human eye has no trouble following a limo moving at 12 mph.

Therefore, if Zapruder's camera was so slow that the slightest movement by Zapruder causes everything in the frame to blur, how was this camera able to catch the rapid bone fragment in almost "stop action" clearness? Worse yet, we are told the fact we can see this one fragment several times in this frame, as it ascends, is because, as we are informed by WC apologists, it is tumbling end over end, and each time it reflects sunlight back to the camera it appears in this frame. What we should be seeing is one long blur ascending skyward. In fact, considering this camera only captured 18.3 frames per second, it is nothing short of miraculous Zapruder's camera was able to capture this fragment at all, and twice, at that; once in z313 and once in z314.

I would appreciate any thoughts or comments you may have on this.

Edited November 4, 2015 by Robert Prudhomme

[Ollie Curme]

Thanks Robert, Interesting post.

The best images I've found for looking at these frames are the MPI cropped frames, reportedly made from the first generation Z film, that is, if you believe the extant Z film is first generation. They can be found here:

https://sites.google.com/site/lightboxzframes/mpi

According to Rollie Zavada (see: http://www.jfk-info.com/zavada1.htm),the exposure time on the B&H camera was 1/40 of a second. We can't tell in what direction the debris is flying; it could be both forward and to one side or the other, but if you assume it is in a plane perpendicular to the axis of the camera, then you will get a minimum distance travelled during the exposure. Let's assume that we're looking at one piece of debris that travels along that line during the exposure time, as opposed to multiple pieces all following each other out (a reasonable assumption because the line is so straight and the blobs are evenly spaced). If the distance travelled is, say, 3 feet, then the speed with which it is traveling would be 3 feet divided by 1/40 second, or 120 feet per second, or 81 miles an hour: a considerable speed!

With respect to blur analysis on that debris, i disagree that each blob should be blurred to the same extent as the points on the car, for the following reason: the points on the car are blurred during the entire exposure time, the full 1/40 of a second. Each round point on the ejection line, perhaps a rotating skull fragment, is exposed for a much shorter period of time. It looks to me like there are clearly 4 instances of the blob (there could be more, but I wouldn't assume exposure started when the blob was at the head). Each instance of the blob takes up less than 1/10 of the length of the line, so the exposure for each blob would be less than 1/400 of a second. Therefore you won't see the same forward blur on the blobs as you do on the car.

I disagree with much of the Warren Commission report, but I find the proposal that the blob is a rotating skull fragment catching the sunlight during each rotation fits the photographic evidence. At that speed, for us to see anything, it would have to be very bright, so it's similar to a stop motion strobe light.

With respect to the blobs continuing on frame 314, I don't see it. I see a diffuse debris cloud around JFK's head, but I don't see a continuation of that debris line. I wouldn't expect to see it either for the following reason:

The camera ran at approximately 18.3 frames per second. Therefore, in every second the shutter was open for 18.3/40 seconds, or a little less than half the time, and conversely, the shutter was closed for a little more than half the time. As a first approximation, the velocity of the debris or blob will continue unabated. This is incorrect, the debris will slow due to the forces of both gravity and wind resistance, but let's ignore that. Between frames 313 and 314, the blob should travel about the same distance it travelled during the exposure in frame 313. So by the start of frame 314, I think it would be out of the picture.

Now, this is all assuming we're looking at a physical thing, as opposed to artwork. It could be artwork, but if so, they were clever about it.

[Jon G. Tidd]

Robert, do you believe the extant Z-film is an accurate record of events?

[Robert Prudhomme]

z314

By following the line of trajectory forward, you can observe a point just level with a point on the woman to the left, just above the hem line of her coat. An object is clearly visible, with possibly a fainter object just below it. This object is not visible in z315.

Do you think Zapruder's camera could capture a clear image of a car going past him at 81 mph, if the camera was held stationary, and not tracking the car?

[Robert Prudhomme]

Robert, do you believe the extant Z-film is an accurate record of events?

No I do not.

[Tom Neal]

According to Rollie Zavada the exposure time on the B&H camera was 1/40 of a second.

The camera ran at approximately 18.3 frames per second.

Ollie,

I used to know all this, but it's been a long time. Am I correct in believing the following:

To use round numbers, let's say that the camera's frame rate was 20 frames a second. Elapsed time = 0 secs. The shutter opens and frame #1 is exposed to light for 1/40th of second. The shutter would then be closed for an additional 1/40th of a second. Total elapsed time = 1/20 of a second. The shutter would again open to expose frame #2. Repeat as necessary...

If correct, then the film records an image for 1/20th of a second, does not record what happens for the next 1/20th of a second, and this cycle is repeated. An analogy would be a human eye that opens for 1/20th of a second, then closes for 1/20th of a second missing whatever happens during that 1/20th of a second slice in time.

TIA,

Tom

[Robert Prudhomme]

According to Rollie Zavada the exposure time on the B&H camera was 1/40 of a second.

The camera ran at approximately 18.3 frames per second.

Ollie,

I used to know all this, but it's been a long time. Am I correct in believing the following:

To use round numbers, let's say that the camera's frame rate was 20 frames a second. Elapsed time = 0 secs. The shutter opens and frame #1 is exposed to light for 1/40th of second. The shutter would then be closed for an additional 1/40th of a second. Total elapsed time = 1/20 of a second. The shutter would again open to expose frame #2. Repeat as necessary...

If correct, then the film records an image for 1/20th of a second, does not record what happens for the next 1/20th of a second, and this cycle is repeated. An analogy would be a human eye that opens for 1/20th of a second, then closes for 1/20th of a second missing whatever happens during that 1/20th of a second slice in time.

TIA,

Tom

Interesting, Tom. When you put it that way, it seems as though the lens only opens once per frame, for 1/40th of a second.

[Robert Prudhomme]

For an example of blurring, here is z301:

Notice how clear the limo occupants are, and how blurred Jean Hill and Mary Moorman, standing on the grass, appear to be. This is because Zapruder has focused his movie camera on the limo as it moves from left to right across his view at 12 mph, a very slow speed, I daresay.

If the limo had been travelling, in the same fashion, at 81 mph, and Zapruder had successfully tracked the limo (no blurring of limo occupants), would the bystanders appear almost 8x as blurred?

[Chris Newton]

Hey Bob,

Didn't Costella address this, (the blurring anomalies), in "The Great Zapruder Film Hoax"?

[Thomas Graves]

[...]

Do you think Zapruder's camera could capture a clear image of a car going past him at 81 mph, if the camera was held stationary, and not tracking the car?

No. An "exposure time" or "shutter speed" of 1/40 sec. is pretty slow.

IMHO, the car would be blurry as hell.

--Tommy

[Thomas Graves]

[...]

Do you think Zapruder's camera could capture a clear image of a car going past him at 81 mph, if the camera was held stationary, and not tracking the car?

No. An "exposure time" or "shutter speed" of 1/40 sec. is pretty slow.

IMHO, the car would be blurry as hell.

--Tommy

PS Nice find (by whomever) of the flying fragment which is visible to the right of the lady on the grass.

[James R Gordon]

This copy of 313 - that was given to me by Chris Davidson - allowed me to zoom into the head explosion.

Chris Davidson's copy of 313 is the best I have which allows me to look at the detail of the head explosion.

It is not possible to distinguish what is bone matter and what is brain matter.

But this copy certainly shows matter flying in all directions.

[Robert Prudhomme]

This copy of 313 - that was given to me by Chris Davidson - allowed me to zoom into the head explosion.

Chris Davidson's copy of 313 is the best I have which allows me to look at the detail of the head explosion.

It is not possible to distinguish what is bone matter and what is brain matter.

But this copy certainly shows matter flying in all directions.

Amazing stop action frame for a camera that blurs with the slightest movement of the person using it, wouldn't you say?

[Ollie Curme]

According to Rollie Zavada the exposure time on the B&H camera was 1/40 of a second.

The camera ran at approximately 18.3 frames per second.

Ollie,

I used to know all this, but it's been a long time. Am I correct in believing the following:

To use round numbers, let's say that the camera's frame rate was 20 frames a second. Elapsed time = 0 secs. The shutter opens and frame #1 is exposed to light for 1/40th of second. The shutter would then be closed for an additional 1/40th of a second. Total elapsed time = 1/20 of a second. The shutter would again open to expose frame #2. Repeat as necessary...

If correct, then the film records an image for 1/20th of a second, does not record what happens for the next 1/20th of a second, and this cycle is repeated. An analogy would be a human eye that opens for 1/20th of a second, then closes for 1/20th of a second missing whatever happens during that 1/20th of a second slice in time.

TIA,

Tom

Tom, yes, you are correct, according to Zavada. During one second, the shutter is open for 18.3/40 seconds and then closed for 21.7/40 seconds, so it's closed for roughly half the time.

With respect to the clarity of the blob moving at high speed, I'm not surprised that there is not more blurring. There is a lot of blurring: the blob seems to move for at least 3 feet: that object is blurred over the entire distance. We just see distinct instance of it during the blur as it rotates and catches the sunlight, again, as in stop motion strobe light photography.

I've been spending a lot of time recently trying to find evidence for the car stop. One thing to look for are frames in which both the background and the limo are not blurred. This could only happen if the limo is very slow or stopped. The relative blur between the limo and the background seems to substantially decrease between Z297 and Z321 which is the same time period Bobby Hargis moves forward relative to the limo. Marie Muchmore in Z297 is much blurrier than Toni Foster in Z321:

I think the blur analysis can be used to quantify the degree of limo slow down although I haven't done it yet.

Of course this all assumes that the Z film is authentic and no frames have been removed to hide a limo stop. I'm trying to figure out how you could remove frames without making the limo occupant and Toni Foster motion look jerky. Greer's head snap between Z316 and Z320 certainly looks jerky, but Toni Foster's walking doesn't. I'm trying to figure out how that could have been done.

So all in all, I think blur analysis is an important component in Z film study and I am looking at ways of quantifying it.

Best

Ollie

[Chris Davidson]

Using JFK as the marker with the pedestal and yellow curb stripe as stationary items, the extant Zfilm shows the limo traveling approx 7.2ft from frames 301-313.

18.3/12 = 1.525 x 7.2 = 10.98ft per sec /1.47 = 7.47mph

chris