Compositing hair to match a new background

- [Voiceover] In this movie,…we'll composite the wispy, voluminous, untamed hair…against the new background.…I'll go ahead and start things off…by deploying the alpha channel as the layer mask,…which you do by control or command clicking…on the layer mask thumbnail,…or, in our case, you can press control alt 7,…or command option 7 on the Mac.…Then switch back to the composite RGB image,…return to the layers panel,…and click on the "add layer mask" icon…at the bottom of the panel…in order to convert the selection to a layer mask.…Next I'll go ahead and rename this layer "hair,"…and I'll press the enter key.…

All right, now you can already see…that we have some haloes around the hair details,…but that's going to work itself out just fine.…All right, next I'll press the M key to switch back…to my rectangular marquee tool,…and then I'll right-click inside the image window…and choose "duplicate layer."…Next I'll change the document setting…to the image that contains the background,…and I'll click okay.…All right, now if I switch to that very image,…