Subject: Re: The Zapruder film is authentic Date: Mon, 03 Aug 1998 12:18:14 -0700 From: David Wimp To: AnthonyMarsh My frames that include sprocket holes are quite poor and low resolution. I can't really make very accurate measurements. I get about 25% of total frame size for the inter ghost distance, but this is very rough. As far as I can tell, you have the right numbers for this. In think the explanation of the gap between ghosts, in very general terms, is something like this. There has to be a "light seal" between the place where the film is exposed and the rest of the film. There is some kind of aperture plate to protect frames adjacent to the one being exposed (or at least the parts of them that aren't inside the light seal), but the rest of the film has to be protected from exposure also. At some point, the film passes this light seal both coming into the exposure are and leaving it. The top of the bottom ghost and bottom of the top ghost are the boundaries of the light seal. This would mean that the aperture plate did not need to cover a complete frame but only parts of the previous and next frames. I don't guess I need any notoriety. You can withhold my name. I don't have all the frames with sprocket holes, so I can't check some of the ones you sent me. I have seen some of them already. When I get the DVD, I will check them all. In the meantime, I found a very good example. In frames 280... the leftmost column of the peristyle is just visible in the upper left corner of the frame as it begins to appear in the upper ghost. It doesn't line up right. The ghost is to the left of the proper image, but pincushion distortion causes that exact effect. (The ghost image is a good bit farther from the center of its picture than is the proper image.) I am sending another picture that shows the peristyle well. I am just pasting it because that is the only way I can find to send compressed images. The plaque is just to the right of the rightmost seam in the sidewalk. BTW, I don't know if you are aware that the lamps on the north side of Elm have been moved and a number were added on the other side. That is why they don't line up right in the pictures. -- Dave [Image]