I left the Zapruder film panel presentation at COPA '98 in Dallas with more questions than I'd had when I arrived. So I embarked on my own study of the Zapruder film. Along the way, I read all or part of three books and spent a lot of time looking at pictures. I was continually surprised at the range of issues connected to the film. From the chain of possession to the interpretation of the images, Zapruder's movie of the murder always seemed to have a plot twist. Here's one of them.
CE 885, the Warren Commission's incomplete reproduction of the Zapruder film in Volume XVIII, includes the intersprocket portion of the film. That area shows two well-defined regions of double exposures, one adjacent to each sprocket hole. The double exposure atop the lower sprocket hole shows buildings and the sky and trees as the film advances. The double exposure below the upper sprocket hole shows a stretch of pavement, a lane line, the shadow of a car and part of a motorcycle apparently to the right, rear of Kennedy's limousine. Some foliage follows. These scenes are clear in the 1998 MPI Media Group video reproduction of the Zapruder film, Image of an Assassination.
From another COPA member, I had learned of Anthony Marsh's explanations of the origins of the double exposures that they were the consequence of the shape of a particular part of Zapruder's camera.
As the film proceeded through the camera, it was sandwiched between two strips of metal. The top strip had a pattern cut out of it. That cutout, or gate, permitted light to fall on the film when the shutter was open. That pattern was also cut to accommodate the "claw," which engaged the sprocket holes and pulled the film through the gate.
In July of 1999, I located an article by Roland Zavada on his study of the film for the ARRB ("Dissecting the Zapruder Bell & Howell 8mm Movie Camera," http://www.pe.net/~atd/xavata1.htm). Zavada reproduced a drawing of the camera's mechanism which included the claw cutout. I found his account of the double exposures to be consistent with my own observations of the Commission's exhibit and the MPI video. Zavada wrote:
The drawing shown provides the representative dimensions of the aperture, which limits image height, inside edge and shows the cutout for the intermittent claw. The characteristics of the aperture cutout are directly related to our study of image anomalies, note the size and location of the cutout for the pulldown claw adjacent to the Standarized (0.192 in. nom. width) image area. Note that the height of the opening for the claw movement is necessarily greater (0.263 in.) than the perforation pitch (0.150 inch) plus one perforation height (0.050 inch). The significance of the size of this opening will be emphasized when we discuss Multiple Exposure Areas.
The cutout physically defined each frame and its corresponding areas of double exposure. Objects seen in the double exposures, like the motorcycle, can and do exhibit motion; but the double exposure areas are fixed with respect to the sprocket holes, so they can not display progressive displacement. They can't move.
That's what I concluded, anyway. Nevertheless, watching the MPI video, I discovered that there is a region of apparent double exposure that does move. I call it the phantom sprocket hole.
At about frame 306 in MPI's slow-motion reproduction of the Zapruder film with its intersprocket images, a noticeably lighter region peels away from the bottom of the upper sprocket hole and begins to move downward through the intersprocket space. The shape does not contain images of people or objects, or at least none that I can discern. It is distinguished from the background because it is lighter and occasionally exhibits a faint, slightly darker outline. As the shape moves, it is easily seen to be that of a sprocket hole. Transit time between the real sprocket holes is about 100 frames. All four rounded corners can be seen at points in the phantom hole's run. The phantom can even be detected in the Warren Commission's poor reproduction of the film. The area enclosed by a double line in diagram B shows the position of the phantom at roughly frame 360.
Having discovered one moving sprocket hole, I looked through the film for evidence of others. If there was a phantom between frames 1 and 100, I could not detect it. (I'm not saying there isn't one there. I'm simply saying that with the materials available to me, I can't find one.) I caught glimpses of a phantom between frames 160 and 175 of the MPI video. I counted a definite phantom between frames 225 and 300. Between frames 300 and 400, there was the phantom I had first noticed. Frames 435-440 hinted of a phantom.
The cutout explanation for the most obvious double-exposures is convincing. It does not explain the phantoms, however. Nothing in Zavada's article suggested a mechanism responsible for them, and they don't appear to have been among the aspects of the film he studied. The seeming periodicity of the effect interested me, but I have no explanation for it. It is my hope that others following this topic will be able to explain the effect and advance our understanding of the film.
Return to Main Page
* * *