23-08-2013, 06:24 PM
Here's where I am coming from:
Months ago as a 50 Reasons episode featuring Robert Groden was being assembled, I pointed out to Len that Groden stated directly that the Z-film was authentic and claims of alteration were wrong, and that by featuring that statement we were making an editorial statement. Len was more equivocal, feeling that this was simply Groden's opinion that was being offered. But I thought that, in the absence of dealing with alteration arguments later in the series, there was something of a party line being effected here and I wanted to feel comfortable in my own mind that I could stand by what Groden said - and I mostly do.
I realize that I've kind of jumped into this forum with some broad claims which go against a long-running current - but my observations are based on many years involved in film-making, which I can detail as this goes on (if it goes on). I'm going to make one point in this reply, then I'll follow with another reply with point 2.
16fps - 48fps I don't know of any film camera which can make a sudden radical switch in frame speed without the high probability of film jam or snapping. The only method is ramping the speed more gradually. If the Z-camera claims that it can switch frame rates during filming, then it has a ramping feature built into the mechanics of the spring wind. Bottom line: you cannot switch frame rates instantly mid-shot.
The effect of ramping the speed would create visible artifacts. The iris must adjust, as at a higher frame rate each individual frame is exposed in the gate for a briefer fraction of a second, and so more light must be let in. If the camera switched speeds mid-shot, the iris change would be visible over a number of frames, either under or overexposed.
Zapruder appears to be steadying his camera with both hands. The act of moving one hand to the speed switch and engaging it would create a visible disruption in the camera's panning movement.
So my issue here is a practical / mechanical one. Let's see if any camera people out there can back me up.
Months ago as a 50 Reasons episode featuring Robert Groden was being assembled, I pointed out to Len that Groden stated directly that the Z-film was authentic and claims of alteration were wrong, and that by featuring that statement we were making an editorial statement. Len was more equivocal, feeling that this was simply Groden's opinion that was being offered. But I thought that, in the absence of dealing with alteration arguments later in the series, there was something of a party line being effected here and I wanted to feel comfortable in my own mind that I could stand by what Groden said - and I mostly do.
I realize that I've kind of jumped into this forum with some broad claims which go against a long-running current - but my observations are based on many years involved in film-making, which I can detail as this goes on (if it goes on). I'm going to make one point in this reply, then I'll follow with another reply with point 2.
16fps - 48fps I don't know of any film camera which can make a sudden radical switch in frame speed without the high probability of film jam or snapping. The only method is ramping the speed more gradually. If the Z-camera claims that it can switch frame rates during filming, then it has a ramping feature built into the mechanics of the spring wind. Bottom line: you cannot switch frame rates instantly mid-shot.
The effect of ramping the speed would create visible artifacts. The iris must adjust, as at a higher frame rate each individual frame is exposed in the gate for a briefer fraction of a second, and so more light must be let in. If the camera switched speeds mid-shot, the iris change would be visible over a number of frames, either under or overexposed.
Zapruder appears to be steadying his camera with both hands. The act of moving one hand to the speed switch and engaging it would create a visible disruption in the camera's panning movement.
So my issue here is a practical / mechanical one. Let's see if any camera people out there can back me up.