I am really struggling with a particular edit in FCP 7.
I have a back ground clip which has fades on the opacity. Superimposed onto that in a second shot also with fading in and out opacity. The issue is that I only want one area of this clips opacity to fade in and out as in this specific clip is an object which is very light in colour and I don't want the opacity of said object to change at all, only the opacity of the first.
I know the easiest way to achieve this effect is to add a third duplicated clip and apply a BCC filter to remove the object which is fading in and out of the second. I don't have Boris FX - well as far as I'm aware anyway. However I do have Motion but an rather new to it.
So what I am doing is trying to use part of a cropped clip as an overlay in a sequence, however, when I superimpose the duplicated image onto the original clip, the cropped area is coming up as a black space. How do I get rid of this black area without enlarging the clip. In essence how to I make the area transparent? Do I use mattes? If so how?
I hope this doesn't sound terribly confusing and I hope someone can please help!!