Limousine stopped?

[Bill Miller]

David, its probably reasonable to assume that it is a standard spool length that Zapruder used, (any reasons to think otherwise?) Does anyone have any idea of what happened to the pre motorcycles-motorcade footage? Does it still exist.

MPI not photographing the lead motorcycle footage frames does not mean it is not still attached to the original Zapruder film and it's three original copies.

I also didn't understand what Stephen Turner meant about the Zapruder film being given more credence than the witnesses. Can someone offer anything specific about that position?

Bill

[John Dolva]

new bar estimate : bar 4.85" wide or 13 pixels ie 1 pixel is 0.37", 29 pixels travel between frame 315 and frame 316 (which is consistent with an increase of speed from 27 pixels frame 312 to 313) ie 10.82" travel.

in frame 313 when the area on the ground is considered stationary the area on the bar has moved 22 pixels or 8.14" in 1/35 seconds or 284.9" in 1 second. or 7.91 yards. or 474.6 yards in 1 minute, or 28476 yards in one hour, or 16.2 miles per hour.

10.82 inches between frame 315 and frame 316. at 284.9" in one second. this is 26.3 frames per second.

*if the speed was 8.3 mph this would be 146 inches in one seconds or frame rate of 13.4 fps.

*if the frame rate was 18.3 fps then the travel would be 198 inches in one second or 11.25 mph.

*if the frame rate was 16 fps then the travel would be 173.1 inches in one second which is a speed of 9.84 mph

obviously further measurements are necessary, including error margin analysis. It's interesting to me that the figures I'm getting are sometimes roughly integer multiples/fractions of other estimates. It leads me to think that there is something to this approach, i have an idea of where the factor that is producing these results may be and will post more shortly.

Thank you Robin for the diagram. It had two good results. I already had a slightly poorer resolution copy of that one, so it was good to get a better one. In studying it I found it to be riddled with apparent errors in scale so it set me searching again for another estimate of bar width, I found one at Don Robardeau's gold mine of data on the assassination. So with a new bar size I remeasured and recalculated and came up with the above, plus a thought of where the 'problem' might be. I'll get back on that one.

Marcel, could you reaffirm the time the shutter is open? Also could you comment on the time between when photons hit the film surface and the time that this registers as an image? is this the speed of a film? ASA?

Should this be fruitful, an 'open source' solution would be available to all who wish to use it.

(If one was to regard the existence of previous studies/results as reason for not undertaking any or to short cirquit one then I suppose the Warren Commission Report would be it, or perhaps the KGB investigation, or perhaps the FBIs, Garrisons? hmmm Costella & co? whatever, if those who have studied the murder of JFK can do no more than use these alternative efforts as a means to advertise books I ... groan...whatever. Please release the material as a public document so that all those who feel a need to read it may do so.)

Edited July 12, 2005 by John Dolva

[John Dolva]

new bar estimate : bar 4.85" wide or 13 pixels ie 1 pixel is 0.37", 29 pixels travel between frame 315 and frame 316 (which is consistent with an increase of speed from 27 pixels frame 312 to 313) ie 10.82" travel.

in frame 313 when the area on the ground is considered stationary the area on the bar has moved 22 pixels or 8.14" in 1/35 seconds or 284.9" in 1 second. or 7.91 yards. or 474.6 yards in 1 minute, or 28476 yards in one hour, or 16.2 miles per hour.

10.82 inches between frame 315 and frame 316. at 284.9" in one second. this is 26.3 frames per second.

*if the speed was 8.3 mph this would be 146 inches in one seconds or frame rate of 13.4 fps.

*if the frame rate was 18.3 fps then the travel would be 198 inches in one second or 11.25 mph.

*if the frame rate was 16 fps then the travel would be 173.1 inches in one second which is a speed of 9.84 mph

obviously further measurements are necessary, including error margin analysis. It's interesting to me that the figures I'm getting are sometimes roughly integer multiples/fractions of other estimates. It leads me to think that there is something to this approach, i have an idea of where the factor that is producing these results may be and will post more shortly.

Thank you Robin for the diagram. It had two good results. I already had a slightly poorer resolution copy of that one, so it was good to get a better one. In studying it I found it to be riddled with apparent errors in scale so it set me searching again for another estimate of bar width, I found one at Don Robardeau's gold mine of data on the assassination. So with a new bar size I remeasured and recalculated and came up with the above, plus a thought of where the 'problem' might be. I'll get back on that one.

Marcel, could you reaffirm the time the shutter is open? Also could you comment on the time between when photons hit the film surface and the time that this registers as an image? is this the speed of a film? ASA?

Should this be fruitful, an 'open source' solution would be available to all who wish to use it.

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some further results from choosing to view the 'blurs' as having one meaning

:::zf300.....4"/p 14..5.6"....196"/s,11.13mph,39 p,13fps

:::zf313.....37"/p..........................7.35mph,........13fps

:::zf327....37"/p 15 5.55",..194"/s,.11.0mph,41p, 14fps

:::zf341....48"/p 17.5 8.4",..294"/s,.16.7mph,53 p,13fps

[Christopher T. George]

I also didn't understand what Stephen Turner meant about the Zapruder film being given more credence than the witnesses. Can someone offer anything specific about that position?

Bill

<{POST_SNAPBACK}>

Hi Bill

I recently started to read the book edited by Fetzer, Murder in Dealey Plaza, and Fetzer makes the point in the introduction to the book that the Zapruder film, for better or worse, has come to be regarded as the historical document that chronicles the Kennedy assassination. Then, of course, the book goes on to cast doubt on film with Jack White and others pointing out anomalies in the film. The case is made by Fetzer that while witnesses can be expected to disagree about what they saw, heard, or experienced, a cine film, presumably, "cannot lie." Fetzer, White, and their supporters appear to show that at the least the existing film appears to have been doctored, if not totally faked as White seems now to be saying, if you read his posts in this forum.

Best regards

Chris

[John Dolva]

hopefully if this technique can be refined and shown of value then it might go some way in indicating whether this or that film is faked/doctored/genuine.

so far using this way of looking at differential 'blur' values on individual still images I am beginning to have a consistent result. latest is frame 276 of zfilm and its equivalent in the muchmore series of still images that makes up what is called 'the muchmore film'.

frame 276 zf:11 mph, muchmore equivalent 14 mph, the error in the muchmore would be greater as I am using a far more grainy version (yet another reason for free access to quality material)

in the images so far processed using this particular way of looking at the relative motions it seems that the limo travelled at a roughly even speed of 11 mph till about frame 300 when by 313 it had slowed to 7+ mph and then sped up again to 11 by zf 327 and 16mph by zf 241. during this time the frame rate seems to be about 13 + fps

zfilm

frame..............speed mph..............frame rate

276..................11...........................

300..................11.13.......................13

313..................7.35.........................13

327..................11............................14

341..................16.7.........................13

hmm this makes me think I should get on with some more of the zfilm panoramas to seek verification. also is it reasonable for the speed to be from 7.35 to 16.7 mph in 2 seconds. well thats another question as well.

Edited July 12, 2005 by John Dolva

[John Dolva]

some further figures

zf#......mph.......fr

282......9.1.......20

288......9.5.......22

294......8.3.......20

300......8.0.......23

304......7.8.......24

310......3.8.......17

316......5.7.......22

322......7.5.......23

328......7.5.......24

334......8.9.......24

again, this is viewing the difference in another way, a consistency is an even speed up to about frame 304 then a rapid deceleration followed by acceleration, and a consistent frame rate. this time the frame rate is an average of 22. I'm deducing that the consistencies indicate the overall idea is ok, some constant and/or the way of measuring is not right hence the variance of sets of results. Obviously the frame rate can't be 13 and 22, or the speed 9 and 11 mph. I think it would be good if someone else would figure out for themselves how to do it and produce a set of results to compare.In the meantime I'll plod on. I'm finding this intersting in an exercise in emipricism that my nature as 'artist' is not so suited for. My daughter did some maths homework with me yesterday, she said she prefers english lit because there's more room for imagination, I know what she means. I am slowly getting an idea of how to work out error margins. One of the difficult things is in choosing HOW one looks at the differences in 'blur' values. It seems to me there are 4 basic ways. Probably if I had an uncorrected, undeblurred (wonder if the government could act on a suggestion of defacement (smoothing, correcting, deblurring)of public property(zfilm)? Nah , prob not, just trying to think of ways to agitate for release of quality data.) set of images it would be easier. But primarily here, as I stated in the beginning of this exploration, my aim is to see if it's possible to take a single photograph and knowing the time the shutter is open and the dimensions of an object in the photo, hence know the dimensions of a pixel and from that work out relative speeds of objects in that photo. In the case of a series of still images that make up a film this could be used to work out frame rates, and possibly cross reference to other groups of photos, other films or individual photos. Unfortunately photographers have a tendency to discard 'poor shots' and look for cameras that have a high shutter speed and 'fast' films. But I'm sure there must be a pile of these discarded images around. (I wonder if an invention might be brewing here, ie a new, rough way of capturing data inexpensively without need for instruments to measure speeds. I find it hard to think I'm the first to think of that though. I did a search and could find no reference to it as yet.Perhaps a camera built to have precise longer shutter open time, with accurate media for use by people who want idea of speed of things, like bird watchers, sports photography, hmm...existing digital cameras with precisely known 'open speeds' married with appropriate interpreting software? motion detection?) Anyway that's a side issue.) Hmmm...if there has been a tendency to alter the 'known' images, perhaps among these discarded ones there would be more likely to be ones that have NOT been altered?

[John Dolva]

some further figures

zf#......mph.......fr

282......9.1.......20

288......9.5.......22

294......8.3.......20

300......8.0.......23

304......7.8.......24

310......3.8.......17

316......5.7.......22

322......7.5.......23

328......7.5.......24

334......8.9.......24

again, this is viewing the difference in another way, a consistency is an even speed up to about frame 304 then a rapid deceleration followed by acceleration, and a consistent frame rate. this time the frame rate is an average of 22. I'm deducing that the consistencies indicate the overall idea is ok, some constant and/or the way of measuring is not right hence the variance of sets of results. Obviously the frame rate can't be 13 and 22, or the speed 9 and 11 mph. I think it would be good if someone else would figure out for themselves how to do it and produce a set of results to compare.In the meantime I'll plod on. I'm finding this intersting in an exercise in emipricism that my nature as 'artist' is not so suited for. My daughter did some maths homework with me yesterday, she said she prefers english lit because there's more room for imagination, I know what she means. I am slowly getting an idea of how to work out error margins. One of the difficult things is in choosing HOW one looks at the differences in 'blur' values. It seems to me there are 4 basic ways. Probably if I had an uncorrected, undeblurred (wonder if the government could act on a suggestion of defacement (smoothing, correcting, deblurring)of public property(zfilm)? Nah , prob not,  just trying to think of ways to agitate for release of quality data.) set of images it would be easier. But primarily here, as I stated in the beginning of this exploration, my aim is to see if it's possible to take a single photograph and knowing the time the shutter is open and the dimensions of an object in the photo, hence know the dimensions of a pixel and from that work out relative speeds of objects in that photo. In the case of a series of still images that make up a film this could be used to work out frame rates, and possibly cross reference to other groups of photos, other films or individual photos. Unfortunately photographers have a tendency to discard 'poor shots' and look for cameras that have a high shutter speed and 'fast' films. But I'm sure there must be a pile of these discarded images around. (I wonder if an invention might be brewing here, ie a new, rough way of capturing data inexpensively without need for instruments to measure speeds. I find it hard to think I'm the first to think of that though. I did a search and could find no reference to it as yet.Perhaps a camera built to have precise longer shutter open time, with accurate media for use by people who want idea of speed of things, like bird watchers, sports photography, hmm...existing digital cameras with precisely known 'open speeds' married with appropriate interpreting software? motion detection?) Anyway that's a side issue.) Hmmm...if there has been a tendency to alter the 'known' images, perhaps among these discarded ones there would be more likely to be ones that have NOT been altered?

<{POST_SNAPBACK}>

if in the photo provided by Robin and Lee the shutter speed is assumed to be 1/35 seconds then the speed of the limousine at this point would be approximately 3.07 mph. however as the shutter speed of this camera is not known all this shows is that it may really be possible to derive the speed in any photo with blurred components using a simple formula and simple data re dimension and shutterspeed.

Edited July 28, 2005 by John Dolva

[John Dolva]

similarly in this photo from Robin and Lee, the speed of the limo. calculated from the differential blur length is about 3.2 mph.

IF the actual speed of the limousine was known at this point, which it may well be, then a reverse calculation would theoretically give the time that the shutter was open on the camera, then a check with the rated shutter speed which also may be known could help on confirming/refining/debunking my approach to calculating limo. (or any object)speed in a photo.

Any info on these data appreciated.

edit::here's the photo

Edited July 28, 2005 by John Dolva

[John Dolva]

I've been removing images to get more 'global space'.

In this image just at the turn into Elm st. using th above formula the speed appears to be about 3.5 mph.