Max of 12 keys applied at once?

I'm running into an odd one that I don't remember happening before. A project containing ~30 multicam clips of subjects over green screen. Basic title slates in between each shot. If we select all the multicam clips (no slates) in the timeline and apply the green screen keyer by double-clicking, it applies the key but the keyer has no visible effect. Each clip shows a key is applied but the controls don't do anything. As a test, we tried cumulatively adding more clips and double-clicking worked until we got to 13 clips selected.

MacOS 15.5, FCP 11.1.1, MacStudio M1 Ultra, 4k footage in UHD multicams, UHD project. If someone has a moment with a similar project, can you run a quick test?

Posted on Jun 9, 2025 5:06 PM

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joema

Level 4

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Posted on Jun 9, 2025 7:25 PM

Terry I tested 30 multicam ranges from the same multicam parent plus 15 additional separate multicams on the same timeline and it seemed to work. That's on the same machine and versions you're running. The built-in green keyer seems a little odd if using on uncorrected S-Log3 clips. At first it seems like the controls don't work, then I turned on the S-Log3 LUT and the keyer worked. The Hawaiki keyer did not do that -- it immediately worked on both uncorrected log and corrected clips. Maybe the default sensitivity ranges on the built-in keyer don't react to a flat log clip?

On your system, is it possible at the 13th MC clip, that flat, uncorrected log clips begin?

Try selecting the last clip where the keyer works, do CMD+C to copy, then select the rest of the clips and do Edit>Paste Attributes and paste the keyer effect on them.

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Max of 12 keys applied at once?

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