trying to key an actor in studio with a plate of live action from somewhere else. would like to blur the edges of the key on the actor to help sell the effect that this was shot on location. is there a good filter anyone can recommend. also, is there a way to add a gradient blur?
Michael is right, the basic keyer of FCP is worthless.
If you have AE, then Keylight is the way to go. Or Get Primatte Keyer from RedGiant (also available for FCP).
It does an excellent job also within FCP.