Alpha channel from Premiere to Final Cut doesnt work

[Greg Janza]

If you’re doing the keying on your end and sending your client a finished composited clip then there’s no need to export with alpha channel.

And if it looks perfect in your system, export in any format that’s convenient for the client.

I Hate Television. I Hate It As Much As Peanuts. But I Can’t Stop Eating Peanuts.
– Orson Welles

[Allard Depallerd]

Sorry, i must have explained it the wrong way…
I am keying it for this client..and then I send it to him so he can finish the compositing and the final video.
So im doing just the keying for him.. and he finishes the movie

[Greg Janza]

splitting the compositing up between two systems is definitely not an ideal workflow.

I’d recommend that only one of you do the actual compositing. That will allow for the best quality control. If the client wants to do it then just send the green screen shots straight.

I Hate Television. I Hate It As Much As Peanuts. But I Can’t Stop Eating Peanuts.
– Orson Welles

[Allard Depallerd]

yeah that’s what I thought.. but I am afraid I can’t convince him to do this. He want me to key it..but not to do the rest of the video.

So im afraid im still stuck with my initial question..

[Jeffrey Di lullo]

If the alpha isn’t looking correct I’d ask 2 questions:

1) how is he interpreting the alpha: premultiplied or un-premultiplied. Then make sure that it matches what you are outputting.

2) Can his system correctly read the Cineform codec. Have you tried sending the clip as ProRes 4444?
Larry Jordan recently wrote an article about Cineform and FCPX (Not sure how helpful it is in your situation as it doesn’t directly relate to keying). https://larryjordan.com/articles/problems-with-final-cut-pro-x-and-gopro-cineform/

What would it look like if you just sent over a black and white alpha matte of the keyed clip and the original clip (two clips) and have him use that to key in FCPX. You can render the alpha matte pass as PhotoJpeg or a PNG sequence or whatever you like. Considering that he wants to finish the composite in FCPX this would actually give him better control over the final composite and would be my preferred method.

Jeffrey Di Lullo
jeffedits.com

[Allard Depallerd]

Thank you for your reply,

You say ” how is he interpreting the alpha: premultiplied or un-premultiplied. Then make sure that it matches what you are outputting. ”
How can he see (and change) how he’s interpreting the alpha?

That last solution sounds good.. So basically im sending him the alpha matte, which he will use to key right?
But can you tell me how I would export this? I have my footage, with the ultrakey effect on it to make it transparent. How would I turn this into a black white alpha matte that I can export?

thanks in advance.. your help is apprectiated!

[Jeffrey Di lullo]

Go to about 4min in this video to see how FCPX is handling/interpreting the alpha you are giving him.
https://www.provideocoalition.com/fcp-x-and-alpha-channels/
Have him toggle the alpha handling setting to see if that fixes the alpha for you. If it does great!

To export b/w alpha matte pass:
Go into UltraKey and change “output” to “Alpha Channel”. This will give you a black and white alpha matte pass. Export the clip.

Jeffrey Di Lullo
jeffedits.com

[Allard Depallerd]

Thank you so much Jeffrey, Ill look into it right away. Does it matter how I export the matte? Is a H264 MP4 fine ?

Ill let you know how it went, thanks again

[Jeff Pulera]

While sending a matte will work, it’s double the effort for you and the editor, with double the files and editor needing to set up the matte key composite for every clip.

I’m assuming you are on a PC, otherwise you would just export as ProRes for him.

Try this – download the Avid DNxHD codecs from Avid, which will allow you to create QuickTime .mov files with ALPHA that certainly ought to work in FCP. Editor may need to also install same codecs on his Mac. They are free.

https://avid.force.com/pkb/articles/en_US/Download/en423319

Thanks

Jeff Pulera
Safe Harbor Computers

[Allard Depallerd]

Thank you Jeff for your reply, i have downloaded and installed the codecs..
In the PP export window, i choose the DNxHR/DNxHD MXF OP1a format but then, i can choose from many different presets..
Im an not sure which one i need to choose, and how to enable the alpha in this preset

The source material is from a Canon 5D mark III (25fps, progressive)

SO can you help me out with the preset and setting i need to choose from this list?

thank you in advance!