24-08-2013, 02:30 AM
hi David
thanks for passing along this information. I appreciate it as I have appreciated your grasp on other issues too.
I think the murkiness of the Z-film chain of custody has been well established by the ARRB, so I really have no problem with the notion that the current "camera original" is not actually the "camera original" which passed through Z's camera at 12:30 PM Nov 22.
Not sold on the foreground/background focus/blurry. Let's put that aside.
Some distinctions need to be made about the spring-wind mechanism of the camera. There are basically two things going on: first, winding the camera using the crank - you turn it until it resists, at that point you are at full wind or full crank, and this will allow for continuous filming to the point that the wound spring is spent. I'm sure there are numbers available for the duration of a full wind with that Bell and Howell. This model camera was touted by the manufacturer for maintaining its torque throughout the duration of a full wind, meaning that the speed of the frames passing through the gate was fairly consistent. But the operative word here is consistent, and that is not the same as "constant". And in that distinction is the crux.
The second thing that is going on is that the individual frames are being moved through the camera's gate, momentarily pausing for exposure, followed by the next frame etc etc. Pearse: the Bell and Howell movie camera was a spring-wound camera, with a constantly varying operating speed. What he means by this is that the rate of the frames themselves, moving through the gate, is constantly in variance. A little faster, a little slower - with no rhyme or reason. What he is saying, and what I discovered several years ago working with a different film, is that if we take, for example, a 100 frame section of the Zapruder film (let's say arbitrarily Z223-Z332) - those hundred frames would have passed through the Z-camera with some frames at 16.5fps, some at 17.1 fps, some at 18.2 fps - and absent a digital clock in the frame counting off to the 1/100th of a second, there would be no way to measure this. It is random. This is a feature of the spring mechanism. This is why spring wound cameras are never sync cameras. (I have spent a lot of professional time considering frame rates and synchronization issues).
Put another way: let's say we have 182 frames of the Z-film before us. Since we know that speed tests established an average frame rate of 18.2fps - it seems a safe bet to say these 182 frames represent 10 seconds of "real time". Unfortunately, you can't really say that. It would more than likely be pretty close to 10 seconds, but it could be 9.6 seconds or it could be 10.4 seconds. Impossible to know (absent a digital clock in the frame). By the same token, you could not go to the 91 frame mark of the 182 frames and say that was exactly 5 seconds in "real time".
The Greer head snap issue rests, I am suggesting, in this distinction - helped along by the 18fps average (meaning, if the Z-camera ran at 24fps, this phenomena would likely not be observable). The fact that this sort of jump happens several times in the film serves to doubly convince me it is related to the camera (while realizing that others may see it as confirmation of alteration).
How am I doing with this explanation?
thanks for passing along this information. I appreciate it as I have appreciated your grasp on other issues too.
I think the murkiness of the Z-film chain of custody has been well established by the ARRB, so I really have no problem with the notion that the current "camera original" is not actually the "camera original" which passed through Z's camera at 12:30 PM Nov 22.
Not sold on the foreground/background focus/blurry. Let's put that aside.
Some distinctions need to be made about the spring-wind mechanism of the camera. There are basically two things going on: first, winding the camera using the crank - you turn it until it resists, at that point you are at full wind or full crank, and this will allow for continuous filming to the point that the wound spring is spent. I'm sure there are numbers available for the duration of a full wind with that Bell and Howell. This model camera was touted by the manufacturer for maintaining its torque throughout the duration of a full wind, meaning that the speed of the frames passing through the gate was fairly consistent. But the operative word here is consistent, and that is not the same as "constant". And in that distinction is the crux.
The second thing that is going on is that the individual frames are being moved through the camera's gate, momentarily pausing for exposure, followed by the next frame etc etc. Pearse: the Bell and Howell movie camera was a spring-wound camera, with a constantly varying operating speed. What he means by this is that the rate of the frames themselves, moving through the gate, is constantly in variance. A little faster, a little slower - with no rhyme or reason. What he is saying, and what I discovered several years ago working with a different film, is that if we take, for example, a 100 frame section of the Zapruder film (let's say arbitrarily Z223-Z332) - those hundred frames would have passed through the Z-camera with some frames at 16.5fps, some at 17.1 fps, some at 18.2 fps - and absent a digital clock in the frame counting off to the 1/100th of a second, there would be no way to measure this. It is random. This is a feature of the spring mechanism. This is why spring wound cameras are never sync cameras. (I have spent a lot of professional time considering frame rates and synchronization issues).
Put another way: let's say we have 182 frames of the Z-film before us. Since we know that speed tests established an average frame rate of 18.2fps - it seems a safe bet to say these 182 frames represent 10 seconds of "real time". Unfortunately, you can't really say that. It would more than likely be pretty close to 10 seconds, but it could be 9.6 seconds or it could be 10.4 seconds. Impossible to know (absent a digital clock in the frame). By the same token, you could not go to the 91 frame mark of the 182 frames and say that was exactly 5 seconds in "real time".
The Greer head snap issue rests, I am suggesting, in this distinction - helped along by the 18fps average (meaning, if the Z-camera ran at 24fps, this phenomena would likely not be observable). The fact that this sort of jump happens several times in the film serves to doubly convince me it is related to the camera (while realizing that others may see it as confirmation of alteration).
How am I doing with this explanation?