I am really stuck with this one and have had a damn good look around before coming here for help. I have downloaded a video of some theatre curtains that open and close. When the curtains open they reveal a black background. I would like to replace the black background with a video so when the curtains open it looks like the video was hiding behind the curtain. I have tried Luma Key and I simply cannot get it to work so that I cannot see the image hiding until the curtains open.
1. It's H.264, so it doesn't have an alpha channel.
2. There are lots of shadows in and around the curtains, which makes it difficult to key. The example you have shown has been sped up to cover the many key imperfections.
So I gave it a try and I have been able to create a pretty neatly keyed ProRes444 file with alpha channel that you just have to put above any footage in FCPX to get instant curtain reveal and closing over your footage, without having to do anything
Here's the result in FCPX:
The 4444 file is 438MB. If you would like to get it, e-mail me at ronnycourtens(at)mac(dot)com and I will send a link for you to download it (for free, of course).
Once again your willingness to go the extra 10 miles to help folks out is amazing.
How do you find the time? I also appreciate how kindly you reply to folks.
Wish everyone here would follow your example.
Just for the record:
> in the time that passed since the first posting/request FCPX got the draw mask effect which effectively enables rotoscoping good enough to animate the matte for the "screen". Apart from such a cheesy wedding filmers' opening (not meant condescendingly, coming from a wedding videographer), it can be useful for secondary CC (best of course with TrackX or Chromatic) or (search on Youtube) "draw mask transitions". Imo it should be considered a basic skill for editing (although it actually is compositing).
> the red curtain is rather from a punch & judy show than from a cinema (scale, curtain color). As a former projectionist, I have seen red curtains, but modern houses (selected ones, most had no more curtains) used dark blue velvet. The red borders bled too much into the image. One could make a more realistic curtain. While it opens, the yellowish room lights would dim. The image on the screen would be projected on the curtain as well. There would be a transition from low contrast and a yellow cast to full visibility as the lights come down. The rounded borders of the curtain would reflect a portion of the image directly from the screen (could be tricky).
> I like the sound. It could do better with some added reverb or so to scale it up to some extend. In reality, you would hear the friction sounds of a steel cable over little wheels and a majestic hiss (if it's a big curtain). But the sound sells the effect quite well.
Axel wrote: … cheesy wedding filmers' opening … the red curtain is rather from a punch & judy show than from a cinema ….
to drop my 5¢ …
the largest cinemas in my tiny village do have curtains - alone, to avoid dust&dirt from the precious 3D screens
… the blue one has DolbyAtmos, so, before the movie you get stunned by flashlights in the walls and a 178dB sound thunderstorm - all instincts yell "run!!"… (and before that, the THX*-trailer blew my popcorn away)