Adding more of the scene to the green screen

[thiswayup]

I have a scene where the green screen doesnt quite cover the whole thing. The presenter and main green is ok but I want to extend the green screen to cover the sides and top and apply ultra key on it after.

What's the best way to do this? I am also open to using After Effects.

Can someone also tell me the advantages of using After Effects for green screen over Premier in the recent versions?

[Meg The Dog · Accepted solution]

My suggestion would be to use an Opacity Mask as a garbage matte:

to reduce down that area that you need to key, then apply the keyer:

MtD

[thiswayup]

Awesome thanks, I'll give this a go!

[Ann Bens]

Gary beat me to it.

You dont extend the green screen you crop it till all non green is gone.

AE has a better keyer (keylight)  then Pr (ultra key).