R3D proxies on green screen. Workflow question

[prop80985291]

Hello,

I have to edit with 4K R3D footage which I also have to key. The problem is that this project has to be done on a PC with much less power that I'm used to, so I have to work with some kind of proxy footage.

My question is: If I key a small proxy, will the keying be flawless when Premiere switches to the 4K clip for export?

If not, am I better off exporting the 4K footage with alpha on the powerful machine and then creating a proxy for that?

Any other suggestions for a painless workflow?

Thanks a lot

[yenaphe]

Do not key on the proxies!

Yes, do key on the original files and then export a matte or a video with Alpha. If you key on the proxies, you won't key the same video source, and you'll be dealing with artifacts (like compression) on the proxy that may not be on the full resolution video

Hope this helps,

Seb

[jasond20891513]

Can you explain how to export a matte or video with alpha? I need to use proxy files with video that is keyed. My video keeps freezing. I think because it's 4k footage. 

[Ann Bens]

Use Cineform or Prores, they can export with an alpha channel.

[jasond20891513]

Is this screen in Media Encoder or Premiere itself?

[Ann Bens]

This screenshot is from AME but Premiere has the same options.