I have this strange case of flicker on a single roll of film we shot. The entire roll seems to have the flicker but it's much more visible in dark scenes. At first I thought that one of my mags was faulty so the motor couldn't establish the film speed correctly so it kept speeding up and down. But I have a cinematography-electronics crystal control for Arri 35-III, and I doubt that it would behave like that and I don't remember seeing the light yellow/orange (which happens when it's not in full speed). Then I thought maybe the batter was too low.
But later I noticed that the brighter parts are not really overexposed (as it would be in the case of speed fluctuations), but they seem to be bluer and hazier/granier. Also when I stop the brighter frames and move frame by frame, I see a "wave" of brightness somehow pass upward on the image, instead of the entire image being brighter equally. And then towards the end of the roll it suddenly stops and the exposure seems normal and colors a bit warmer. On the frame where it switches to normal, it seems the frame is split and the upper part is a bit brighter and lower darker.
All this led me to conclude that it's not the motion of the camera, and that the roll was "flashed" somehow only on one side of it or something to that effect. If that were the case the rhythm of the flicker would accelerate or decelerate over time, depending on whether that happed prior or post exposure in camera (because the head and tail would switch their places from the core to the outside part of the roll). But I didn't measure flicker intervals to determine that. This is a short end, so it could be a loading error either on my part or the person that recanned it prior to me.
But I could be very wrong about this. Maybe it's even a lab mistake? Or is it the camera?
Can someone please take a look at this clip and comment? This is the very last roll of our shoot and a some of the crew staid for champagne to celebrate the wrap so we shot that.
Sorry for the YT compression and softness, but you can see what I'm talking about.