Layering footage - making a background transparent
by Meredith Gooblesby
on
Nov 10, 2008 at 6:50:59 pm
Hello there,
I don't know if you can help me with this as maybe I can only do this in adobe after effects.
I have created some footage of animated hand drawn text in white set upon a black background. I want to layer this over other footage of some people talking (they are also against a black background) in FCP so that the white text obscures the footage and the black areas become transparent. Is this possible in FCP or would I be better off with some other programme? Thanks.
Re: Layering footage - making a background transparent by Dennis Leppell on Nov 10, 2008 at 7:09:37 pm
Three ways to do this....results may vary.
1) Use compositing. Cut the clip into two seperate clips, with the cut point being where you want the black to fade out. On the second clip, where you want your background to be in place, Select a compositing method that works best for the look you want. Cross dissolve between the two clips.
2) Do the animation with an alpha channel, so that instead of black, you have no background. Export with animation codec, millions of colors+, and bring this into FCP. Place onto timeline, with a black matte or slug underneath. Fade out slug at appropriate time.
3) Similar to option 1. Cut the clip into two, on the second clip, select the "color key" filter and key out the black. Crossfade at the appropriate time.
Re: Layering footage - making a background transparent by Meredith Gooblesby on Nov 10, 2008 at 8:06:20 pm
Thank you both for replying. I will experiment with these methods although I am actually a beginner to all of this so this is probably very advanced for me as an 'animation codec' that's something in adobe after effects right, actually could anyone explain what that is? I will have a go and post up the result. Many thanks anyway.
Re: Layering footage - making a background transparent by Dennis Leppell on Nov 10, 2008 at 8:35:33 pm
Here's the quick and dirty explanation...There are many different ways to encode a file. It really comes down to the type of codec used. Quicktime, for example, will play back .mov files, but that .mov file may be a standard quicktime movie, a final cut pro self-contained reference file, an h.264 file, etc. Each type of codec generally has a specific purpose, but they all essentially do the same thing....deliver your video/audio in a format that your video player can understand.
Animation codec is basically a type of quicktime file that includes information about transparent pieces of the video, or "alpha" channel. In the same way that you can export a .tif image from photoshop with a transparent background to include into a video, you use the animation codec to export a .mov to use in Final Cut for animated graphics, like lower 3rds. When you export a video from whatever program you used to animate the handwriting, you want to export as a Quicktime movie, and then change the video compression type to animation. Select color depth to say millions of colors +. The "+" indicates the alpha channel information is included. If you don't do that, all the alpha information will be exported as black.
Re: Layering footage - making a background transparent by Chris Poisson on Nov 10, 2008 at 11:01:22 pm
Marsha,
Nowhere in your original post did you mention the possibility of re-rendering your movie with an alpha channel. The advice to do this is the normal way it's done and you got a good description. The thoughts I left you are ways to use the file you have.
Re: Layering footage - making a background transparent by Tom Matthies on Nov 11, 2008 at 2:54:06 am
Hmmm...Unless I'm reading this wrong, a simple luminance key should do the trick. Just drag the Lum Key filter onto your graphic track which is placed on the track above your background. Set the controls to key out the darker part of the graphic, adjust the sliders until you get the effect you want.
Very easy and simple.
Tom
