Yeah, but which copy?
https://i.servimg.com/u/f35/17/60/28/90/scree628.jpg
Oh BTW... click image for a full page view 
I don't know what the heck you are trying to prove?
The original Zapruder Film is authentic and has been verified as a camera original by The Kodak Expert, Zavada! And as expected the copies which were copied from copies over time have slight colour, quality, etc variations. Big Deal!
Btw is there any Kook theories that you don't endorse?
"The first was Zavada, who even in retirement was the world's leading expert on the 8mm Kodachrome II film that had been inside Zapruder's camera on that fateful day. Nobody would be better suited to examining and authenticating the film than Zavada.The examination
"Zavada identified two primary objectives for his investigation. First, he looked at the original in-camera Zapruder film to verify its authenticity and determine whether some of the anomalies on the film matched the characteristics of the original film and camera, or whether they were, as some theorized, evidence that the film had been altered or edited.
Although the Zapruder film is the most studied film in history, most people had just seen second- and third-generation copies. Zavada was one of a handful of people to see the original since it came out of Zapruder's camera.
"I saw it four times, hands on," Zavada said. "You can tell a lot by feeling the film, in terms of how it's been stored or kept, whether it's fluted, whether or not you have edges that have been damaged. You can just feel the perforation."
By studying the physical characteristics of the film and analyzing the symbols encoded on it, Zavada was able to conclude where the film stock came from.
"One of the things I certified was that Zapruder's film was made in 1961," Zavada said. Zavada analyzed the edge print on the film — machine codes that were added to Kodachrome II during the slitting, spooling and perforating process. "I could tell it was finished in Rochester based upon the codes."
Zavada tracked down the technicians who had developed Zapruder's film in Dallas hours after the assassination and made copies for the Secret Service. He looked at Zapruder's camera, and talked to experts at Bell & Howell to understand its characteristics. He concluded that all of the artifacts on the film had been caused by the camera itself. Some of those anomalies weren't visible on the copies.
e also examined the images that were captured outside of the frame of the film, between the areas punched for sprockets. These images weren't present on the copies, giving further credence to the authenticity of the original.
Zapruder paused filming at one point. He'd started shooting when a police motorcycle turned down Elm Street and stopped when he realized it wasn't Kennedy. He resumed filming some time later, when the president's car first became visible. Some conspiracy theorists suggested the film had actually been spliced.
But Zavada found no evidence of splicing, and instead saw the tell-tale fogging that occurs when a movie camera paused with film in its gate.
Originally intending to spend four days working on his analysis, Zavada spent more than 100, delivering an exhaustive, 150-page report, supplemented with hundreds more pages of notes, appendices and technical documents.
Zavada's report concluded that Zapruder's film was an "in camera original" and that any alleged alterations were not feasible. Any attempt at forgery would have left visible artifacts of "image structure constraints of grain; [and] contrast and modulation transfer function losses. It has no evidence of optical effects or matte work including granularity, edge effects or fringing, [or] contrast buildup."
Zavada concluded that the Zapruder film that the ARRB had was the original and that it had not been tampered with.
"I knew the variability that was in 8mm film," Zavada said. "Film is not precise. It has variables because it is a plastic medium. You don't cut, you shear. You're either punching holes or you're slitting. I knew the difficulty of positioning. I headed the committees on 16 and 8mm technology for the Society of Motion Picture and Television Engineers.""
"If somebody had altered the film," Zavada said from his Pittsford home last week, "they had to do it in a way that I couldn't see."https://www.democratandchronicle.com/story/news/local/2013/11/21/kodak-researchers-helped-analyze-jfk-assassination-evidence/3667753/---------------------------------------
"Zavada has been vehement from the beginning that his study of the film and its authenticity is independent of any content analysis. His examination and investigation is simply of the artifacts presented to him (the camera-original film and its three first generation copies) and their provenance. This was the limit of his investigation and his conclusions. Given these limits he is willing to conclude as follows:
There is no detectable evidence of manipulation or image alteration on the Zapruder in-camera-original and all supporting evidence precludes any forgery thereto.
The film that exists at NARA was received from Time/Life, has all the characteristics of an original film per my report... It has NO evidence of optical effects or matte work including granularity, edge effects or fringing, contrast buildup, etc.
In the world of paintings or antiques, authentication of artifacts is a job best left to experts. The same applies here. In the specialized realm of "questioned document" or "questioned photograph" examination, amateurs venture at their peril. Long before Lifton and Livingstone ventured forth, David Mantik offered his own mistaken theory concerning the Zapruder film as artifact. In an early article in Fetzer's volume, Assassination Science, he opined that the "ghost images" found at times between the sprocket holes signaled alteration of the original film. This thesis evaporated as soon as Anthony Marsh began circularizing snippets of eight millimeter film taken with a similar camera that showed similar ghost images. Later, Zavada showed how the "ghost images" were produced by a simple double-exposure of the primary image. Other amateurish efforts over the years that sought to undermine the authenticity of the film via technical criticism have met with similar fates."https://www.maryferrell.org/pages/Essay_-_Bedrock_Evidence_in_the_Kennedy_Assassination.htmlJohnM
