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compositing, alpha channels, capturing from tape help!!
hello everyone,
so here’s the thing. i need to “reassemble” all the elements of a spot with various graphics. the graphics were handed to me layed out on a digibeta… each spot included a) the graphics as see you see it at output and b) the alpha channel for that graphic. now since they were captured into final cut from tape. i’m guessing there’s no alpha channel…the background is black… so the question is how do i go about compiling all these graphics into a sequence by taking the “black” out and having the graphics look composited…thanks in advance!
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4 Replies
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Carlos,
In your timeline put the video clip with the graphics (Fill) on layer 2, put the clip with the alpha (black and white clip – Matte) directly below it on layer 1. Right-click on the clip on layer two, under composite mode, set it to Travel-Luma. To see if video will play where the graphics aren’t (like in the case of a graphic for a lower-third), move your two clips up one layer and place a regular old video clip underneath. You should see the graphics sitting on top of the video underneath. The key is to make sure your IN point on your Fill matches the IN point on your Matte, otherwise you’ll start seeing a graphics, white mess on top of your video.
Hope this helps,
Jamie Pickell
Mac OS 10 Leopard
Mac Quad-Core Intel Xeon
8GB RAM
FCP 6.04
Kona 3
XRaid
— Just laid my first HD program to tape with fills and mattes at the end -
hey jamie,
thanks for the quick reply!
it works kind of… i can see the “background layer” or the footage wherever i want the graphics to sit… through the graphic.. in other words, i can see the background layer through the graphic since the opacity level on the alpha channel is low… however i still see the black all around it!thanks again for all your help!
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In your first post you mentioned that the clips coming off of the DBeta don’t have an alpha channel, and you are correct. What you are doing is taking the graphic elements (the Fill) and marrying them with white and black images (the Matte). The Matte is your alpha channel for the Fill. You want the opacity of both your Fill and your Matte to be 100 percent, unless you want them not as strong in which case you need to bring both opacities down to the same percentage level. Your Matte should be White where the graphics are visible and black where the video underneath should be showing through. You also want to double check that your Fill IN point matches your Matte IN point. Sometimes graphics guys will put a large X one frame before the start of the Fill and the start of the Matte so you know where to mark your IN point. Otherwise I would try to see if the graphics move at any point and try to match the movement of the Fill with the movement of the Matte.
Hope this helps,
Jamie Pickell -
hmm still not working… ok so, the matte footage is not stright up alpha hard black and hard white… there’s some gray tones.. im assuming for opacity since part of the graphic has lowers opacity levels to show what the background is through the graphic. it is also animated and the background is white! where on the fill the background is black!
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