12-09-2014, 08:17 PM
(This post was last modified: 12-09-2014, 08:45 PM by Drew Phipps.)
After some back and forth about the validity of the Zapruder film on the forums recently, I thought I might use my pixel counting software to see if I could detect anything unusual, by comparing the apparent motion of the limousine across the background of bystanders. I only analyzed Z-frames 277 through 344, reasoning that this was a) the time of greatest interest, and b) the time when the limo was moving nearly perpendicular to the camera. I reasoned that if the limo was moving partially towards the camera, the apparent motion of the bystanders compared to the limo would be too slow.
The limo is being more or less tracked by the camera, but Zapruder's tracking isn't perfect. By comparing the relative position of the limo to the bystanders, I hoped to minimize Zapruder's naturally imperfect tracking. I believe the same technique is used to "stabilize" the image of the limousine on the film. If applied to the film, the limousine would not change its position in the image, but the bystanders would pan to the left.
There are some caveats: Counting pixels always enters an error factor of at least 2 pixels, one on each end of the measurement, as you cannot tell whether a pixel is partially or totally filled with a bit of the image. The Zapruder film is low resolution, even the best images are a bit blurred, and there are many frames in which the blur seems to be the defining characteristic of the image. I tried to minimize the impact of this fact by only reporting here differences in relative movement that exceed 50% of the normal relative speed. Last, I cannot say for sure whether the anomalies I notice below were caused by a Bell & Howard camera malfunction, or by the process of digitalization of the film, or represent actual "cut and paste" editing of the celluloid (or the digitized) film. I used the "Costella" images available on the net at http://www.assassinationresearch.com/zfilm/
I selected a fixed point on the limousine, the upper passenger side corner of the windshield area (there are some sort of grey attachments to the windshield, they come to a sharp point and make an easy reference point). For bystanders, I selected a reference point on each bystander which was visible in all frames in which they appeared. In each frame in which the bystander appeared, I compared its point of reference's apparent movement to the limo's point of reference.
(continued)
The limo is being more or less tracked by the camera, but Zapruder's tracking isn't perfect. By comparing the relative position of the limo to the bystanders, I hoped to minimize Zapruder's naturally imperfect tracking. I believe the same technique is used to "stabilize" the image of the limousine on the film. If applied to the film, the limousine would not change its position in the image, but the bystanders would pan to the left.
There are some caveats: Counting pixels always enters an error factor of at least 2 pixels, one on each end of the measurement, as you cannot tell whether a pixel is partially or totally filled with a bit of the image. The Zapruder film is low resolution, even the best images are a bit blurred, and there are many frames in which the blur seems to be the defining characteristic of the image. I tried to minimize the impact of this fact by only reporting here differences in relative movement that exceed 50% of the normal relative speed. Last, I cannot say for sure whether the anomalies I notice below were caused by a Bell & Howard camera malfunction, or by the process of digitalization of the film, or represent actual "cut and paste" editing of the celluloid (or the digitized) film. I used the "Costella" images available on the net at http://www.assassinationresearch.com/zfilm/
I selected a fixed point on the limousine, the upper passenger side corner of the windshield area (there are some sort of grey attachments to the windshield, they come to a sharp point and make an easy reference point). For bystanders, I selected a reference point on each bystander which was visible in all frames in which they appeared. In each frame in which the bystander appeared, I compared its point of reference's apparent movement to the limo's point of reference.
(continued)
"All that is necessary for tyranny to succeed is for good men to do nothing." (unknown)
James Tracy: "There is sometimes an undue amount of paranoia among some conspiracy researchers that can contribute to flawed observations and analysis."
Gary Cornwell (Dept. Chief Counsel HSCA): "A fact merely marks the point at which we have agreed to let investigation cease."
Alan Ford: "Just because you believe it, that doesn't make it so."
James Tracy: "There is sometimes an undue amount of paranoia among some conspiracy researchers that can contribute to flawed observations and analysis."
Gary Cornwell (Dept. Chief Counsel HSCA): "A fact merely marks the point at which we have agreed to let investigation cease."
Alan Ford: "Just because you believe it, that doesn't make it so."