Creating a luma key

of a green screen or a blue screen background … so you kind of have to improvise. … And in the next tutorial, we'll look at … what to do if you're like really stuck. … But in this tutorial, we're going to look at … how to use a background that is much lighter … or much darker than your subject in order to get a key. … This is called pulling a luma key or a luma matte. … It's one of those really common VFX things … you're asked to do a lot. … I use a luma key on this shot and the assurance … because my portable green screen … wasn't quite big enough to cover Nati … for the entire time that she was walking up. … Also, all this awesome wind that these dudes … were doing were kind of blowing the green screen around … and just making it so it was … just really a challenge anyway. … It was going in front of her, to the side of her. … It was just too much to mess with. … I also realized, hey, I'm pointing up … into a very cloudy Pacific Northwestern sky. … And I knew it was going to composite eventually …