In Friday’s long class, we started by getting more familiar with the cameras. This was very convenient as I got to catch up on what I missed out on in the first class. We spent most of our time learning how to calibrate the viewfinder, solving a problem which I didn’t know existed in the first place!
Next, we did an exercise in focus pulling, involving a demonstration camera operator and focus puller, as well as our model Ayu. First, we staged a path for Ayu to walk along. Next, the focus puller marked where the focus should be for each step of the way. Finally, Ayu would walk her path, the camera operator would pan and tilt to follow her, and the focus puller would pull the focus according to their markings.
This was the first time I’d seen focus pulling in action, and it seemed halfway between useful and overly complicated. I’m sure my hesitations are just because I’m not used to it, and eventually I won’t be able to go back to not having one.
I found it interesting that the hardest thing for most of the demonstration pairs was for the camera operator to pan and tilt to follow Ayu with the camera as she got close to the camera. It must have been because the movements until that point were only small, and that last one much bigger. Because of this, it’s important that camera operators are anticipating what’s coming up, and what they need to do to capture it. Each subsequent camera operator who came up did a better job at this final movement than the last one, as they all realised what had to be done at this point.
I was also interested to find that the scale on the focus ring isn’t linear – a metre difference in focus points far away would only represent a small fraction of the focus wheel, but a metre distance of focus points close to the camera would represent a much larger portion of the focus wheel. This means that if the subject walks gradually towards the camera at a constant speed, the focus puller will start adjusting the focus slowly and end up moving it quite quickly. I think a few of our demonstration focus pullers (including me) didn’t know this and made the final adjustment at a constant pace when it should have been accelerating, leading to an out of focus image during the movement (but still ending in focus). In any case, I found this was a cool and fun little piece of maths, and I’d like to get a better understanding of the technicalities of these systems to see why these relations are the way they are.
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