David Bross

AJA CION with Arri LOG-C3

Resolve DCTL · 2018 · Color science, firmware, development

Before Digilog, before any of the rest, there was this: a DCTL for DaVinci Resolve, written in 2018. It was the first time I ever wrote code for the image, and it changed the way I saw my own work.

The AJA CION was a peculiar camera for its time. It handed you a linear scene signal with no real dedicated gamma curve, and its highlights clipped alarmingly fast. Most people had never worked in a linear-scene space, so the footage felt unforgiving and hard to tame. That frustration is exactly what pushed me into the research, to find a way out.

I loved the camera anyway, and I wanted to pull the very best out of it. So I built a transform that turned its linear signal into an ARRI LOG-C gamma curve, and I shared it freely with the community shooting on the same camera.

Then I went further. I wanted that curve baked in at capture, not added afterwards, so I set out to hack the CION's firmware. I did it in the open: I told AJA exactly what I was doing, and I even asked them for help.

They were generous ( they "congratulated" the work ) but they couldn't hand me the encryption key to the core of the firmware. Not to block me: part of that code was, and still is, running inside products they sell. I understood, and I respected it.

Years later, that relationship came back around. One of their engineers and I traded notes while I was developing the Digital Bolex Reworked.

Presenting the DCTL for the AJA CION camera.
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