The Parallax View

The most famous amateur film of all-time was taken by a gentleman by the name of Abraham Zapruder. Perched high atop a concrete wall in the Dallas suburbs, and clutched by his secretary Marilyn Sitzman to counter his vertigo, he was to film in shocking gory detail the death of a United States President.

To question the authenticity of the film was regarded by many as tantamount to historical heresy. The film represented reality, surely? How, why and who faked it?

The spearhead of this assault on authenticity has been an umbrella group led by Professor James Fetzer whose research is detailed here. One of their points of finding is this photo taken by Dallas Police crime lab Sgt. Pete Barnes on Wednesday, November 27, 1963 from atop Zapruder's 5.3 feet long by 2.3 feet wide pedestal. Coincidentally, a photo taken from across the street at about that same moment, shows Barnes. The photo is the second one on this site. The pictures show the same scene, albeit the Zapruder film shows the top of the Stemmons Sign as being level; the Dallas Police Dept. picture has a slight incline. Critics of this work have brought the point that the lampposts show a significant lean when comparing the photos. When one takes into account the gradient of Dealey Plaza, the lampposts line up perfectly.

The work of Fetzer et al. is duplicated here. When one compares the landmarks of the DPD and a montage of Zapruder images, several discontinues become highly apparent. When one lines up and scales the pictures (with an origin being at the corner of the north-western edge of the Dallas County Records Building, the leftmost 'common' feature unambiguously identifiable in both images), problems are evident. The geographic features furthest from the camera line up reasonably well, although slight discrepancies are due mainly to my scaling calculations, and are out by only a few pixels. These are denoted by yellow lines.

The green lines show the location of the edges of the Stemmons sign and the lamppost closest to Zapruder and it is clear that they do not line up. How can this be? Is this evidence of film tampering?

No. There is a physics phenomena that can easily explain this. It is called parallax and relates to how objects apparently move. A good example of this can be demonstrated simply. Find a vantage point that affords a view of both near and distant objects. Then, move slowly from side to side. It seems as if the objects are moving, but of course this is illusory; it is only apparent motion. This phenomena has a greater impact on the location of near objects than distant ones.

If Barnes and Zapruder were not standing in exactly the same location, then the resultant parallax would have a very significant effect on how the photographed images line up.

To use the Java Applet

The Java Applet (below) represents a highly schematic, illustrative view of Dealey Plaza as seen from the concrete Pedestal on which Abraham Zapruder was perched. The co-ordinates of the Plaza objects have been taken from a survey performed for Don Roberdeau

The small box to the right shows a plan view of the Zapruder Perch (which is highlighted in light grey) and the surrounding North Pergola. By clicking on any location on this grey area, you can see in the larger area to the left the resulting view of the Plaza. As you click around the pedestal area you can see how much of an effect Parallax has on the vista; items in the foreground seem to move much more than objects in the background.

Where possible, I have taken colour samples direct from the Zapruder film, but some of the areas require further discussion: the pink area is the distant wall of the County Records Building; the yellow rectange denotes where the windows would be. For simplicity, I have omitted the jail door, which exists in the wall of the Records building. The light grey area indicates the wall of the north peristyle. I have not modelled the effects of perspective, hence all the walls are parallel.

Marked underneath the Dealey Plaza schematic is a measurement of the locations of the different elements, marked off in degrees. Zero degrees, the "straight ahead" view is parallel to Main Street.

Please activate Javascript and download the Java Runtime Environment.

As one can see, the apparent shift in locations of foreground objects can be easily explained by parallax without the need to resort to complicated theories invoking the use of optical printers to fake portions of the Zapruder film.

Update: I have just received an email from Jack White, who is legendary amongst Kennedy researchers. He suggests that the lamppost "movement" is due to the fact that it has been repositioned. If so, it must have been moved between the Kennedy shooting (November 22nd) and the DPD Photo (November 27th). The lampposts were moved in later years, from the ouside edge of the sidewalk to the inner edge- these posts were moved back to their earlier location for Stone's JKF film, and then presumably moved back (?).

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