Chris Davidson Posted February 20, 2016 Share Posted February 20, 2016 (edited) Zfilm alteration equation coming up. chris Edited February 28, 2016 by Chris Davidson Link to comment Share on other sites More sharing options...
Chris Davidson Posted February 20, 2016 Author Share Posted February 20, 2016 (edited) Edited February 26, 2016 by Chris Davidson Link to comment Share on other sites More sharing options...
Chris Davidson Posted February 20, 2016 Author Share Posted February 20, 2016 Reference material needed. I'll embed and attach these items individually, as I don't know how good they'll look via Photobucket. Link to comment Share on other sites More sharing options...
Chris Davidson Posted February 20, 2016 Author Share Posted February 20, 2016 Reference material: Link to comment Share on other sites More sharing options...
Chris Davidson Posted February 20, 2016 Author Share Posted February 20, 2016 Reference material: Link to comment Share on other sites More sharing options...
Chris Davidson Posted February 20, 2016 Author Share Posted February 20, 2016 Last Piece: Link to comment Share on other sites More sharing options...
Chris Davidson Posted February 20, 2016 Author Share Posted February 20, 2016 (edited) The equation broken down for those who don't want to do the conversion: 15.116ft- Distance from limo front to JFK in limo divide 12 - Total frames from 154-166 =1.259666…. ft per frame x 18.3 - Frames per sec = 23.05ft traveled in 1 second @ 18.3 frames per sec divide 48 frames per sec true camera speed at this point = .48 ft per frame x 5 frames (z161-166) = 2.4ft = distance between JFK and Connally in limo. = 5 true consecutive frames from a 48fps film. Added on edit: I use 1.47ft per sec (rounded off from 1.466) as my multiplier for mph conversions. chris Edited February 20, 2016 by Chris Davidson Link to comment Share on other sites More sharing options...
David Josephs Posted February 21, 2016 Share Posted February 21, 2016 (edited) Bravo Chris.... The 5 48fps frames from 161-166 shown at 18.3fps is effectively hidden and removes the wide turn onto Elm. With these calcs we can find where the film switches from 48fps to 18.3 and back - yes? btw - the limo's lights going on and off can be seen in Jeffrie's film. It does not seem to me the lights blink once they turn on Elm... Edited February 21, 2016 by David Josephs Link to comment Share on other sites More sharing options...
Ollie Curme Posted February 21, 2016 Share Posted February 21, 2016 Chris, I follow you up until your last post. If I understand your analysis, you are assuming that frames 154-166 were recorded at 18.3 frames per second but that 161-166 were recorded at 48 frames per second. What am I missing? Thanks Ollie Link to comment Share on other sites More sharing options...
Chris Davidson Posted February 21, 2016 Author Share Posted February 21, 2016 Chris, I follow you up until your last post. If I understand your analysis, you are assuming that frames 154-166 were recorded at 18.3 frames per second but that 161-166 were recorded at 48 frames per second. What am I missing? Thanks Ollie Bravo Chris.... The 5 48fps frames from 161-166 shown at 18.3fps is effectively hidden and removes the wide turn onto Elm. With these calcs we can find where the film switches from 48fps to 18.3 and back - yes? btw - the limo's lights going on and off can be seen in Jeffrie's film. It does not seem to me the lights blink once they turn on Elm... David, There are three known splices in the film. Probably a good place to start. The 157 splice is the only part I'm concerned with for now, as it sits in between z154-z171. The 48/18.3 ratio may not be as important in trying to determine the film switches. It might be the 18.3/5 = 3.66 x 133 = 486. Depends on whether a repeating sequence was used or was it random. I want to keep my explanation (for now) limited to the equation provided and branch out from there. I hope those interested will gain a better understanding using this method. chris Link to comment Share on other sites More sharing options...
Chris Davidson Posted February 21, 2016 Author Share Posted February 21, 2016 Chris, I follow you up until your last post. If I understand your analysis, you are assuming that frames 154-166 were recorded at 18.3 frames per second but that 161-166 were recorded at 48 frames per second. What am I missing? Thanks Ollie Ollie, The limo travels at the same speed regardless of what camera(with different fps) films it. The limo travels 2.4ft in 5frames according to the extant zfilm. 18.3/5 =3.66 x 2.4 = 8.78 ft per sec = 5.98mph That's why I broke down the limo speed in terms of ft per frame. I was not the one that determined the zfilm ran at 18.3 fps. Try this exercise, figure out the speed of the limo according to both CE884's (@ 18.3fps) Z161-166 and Z168-171 and add those two results? chris Link to comment Share on other sites More sharing options...
Chris Davidson Posted February 21, 2016 Author Share Posted February 21, 2016 The speed of the limo from z154-z166 is (23.05ft per sec) 15.68mph. In 5 more frames up to z171, I will make the assumption it is traveling the same speed. So, z154-z171= 15.68mph. CE884 the orange version, z171-z185 = 17.18mph CE884 the orange version, z185-z186 = 18.673 mph The above speeds of the extant zfilm would appear to be more representative of what we see at this point in time. chris Link to comment Share on other sites More sharing options...
Chris Davidson Posted February 21, 2016 Author Share Posted February 21, 2016 The speed of the limo from z154-z166 is (23.05ft per sec) 15.68mph. In 5 more frames up to z171, I will make the assumption it is traveling the same speed. So, z154-z171= 15.68mph. CE884 the orange version, z171-z185 = 17.18mph CE884 the orange version, z185-z186 = 18.673 mph The above speeds of the extant zfilm would appear to be more representative of what we see at this point in time. chris Average speed of 15.68 + 18.68 = 34.36mph/2 = 17.18mph = z171-z185 average speed Average speed of 15.68 + 17.18 + 18.68 = 51.54 /3 = 17.18mph = average speed of z171-z185 chris Link to comment Share on other sites More sharing options...
Chris Davidson Posted February 21, 2016 Author Share Posted February 21, 2016 The speeds determined for CE884 entries of z161-z166 and z168-z171= 2.24 and 3.74 mph respectively. Their difference is 1.5mph, their sum = 5.98 mph inevitably linked to 2.4ft/5frames@18.3frames per sec That difference equals the same difference in mph as the three previous tiers (over a 1 second time period). 18.68-17.18=1.5mph 17.18-15.68=1.5mph Just doodling. chris Link to comment Share on other sites More sharing options...
Chris Davidson Posted February 22, 2016 Author Share Posted February 22, 2016 The WC had to make adjustments to the vertical as well. Start with this adjustment. z161-166. What a coincidence. 10/12 =.83333 x 18.3 = 15.25ft I hope you really didn't believe it had anything to do with vehicle heights. chris Mr. SHANEYFELT. Yes; because of the difference in the automobiles there was a variation of 10 inches, a vertical distance of 10 inches that had to be considered. The stand-in for President Kennedy was sitting 10 inches higher and. the stand-in for Governor Connally was sitting 10 inches higher than the President and Governor Connally were sitting and we took this into account in our calculations. Mr. SPECTER. Was any allowance then made in the photographing of the first point or rather last point at which the spot was visible on the back of the coat of President Kennedy's stand-in before passing under the oak tree? Mr. SHANEYFELT. Yes; there was. After establishing this position, represented by frame 161, where the chalk mark was about to disappear under the tree, we established a point 10 inches below that as the actual point where President Kennedy would have had a chalk mark on his back or where the wound would have been if the car was 10 inches lower. And we rolled the car then sufficiently forward to reestablish the position that the chalk mark would be in at its last clear shot before going under the tree, based on this 10 inches, and this gave us frame 166 of the Zapruder film. Link to comment Share on other sites More sharing options...
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