I am working with a director who is editing on Avid Media Composer (I don't know the version, but for the sake of conversation lets say MC5) and we're dealing with greenscreen footage.
He wants me to handle some of the more difficult keys in After Effects. My question is this: If I create an alpha channel (simple black and white video) in After Effects for the chromakey, does Avid have an effect that can apply that for transparency?
The clients will see previews along the way so we want the keys to be relatively clean without having to wait until the finishing stage.
You can export your Alpha only from After Effects and have it brought into Media Composer. Within Media Composer, they can use that grayscale image as a luma key. Keep in mind, with chroma keyers like Keylight that has built in spill suppression, that won't carry over, but like you mentioned, if this only to be used as previews, you should be fine.
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