Introducing the Calculations command

- [Deke] Now it's great…when you can create an alpha channel,…and by extension, a layer mask…based on a color-bearing channel…as we did when selecting the sky…based on the contents of the blue channel…but most masks are not that simple,…which is why in this movie,…I'll introduce you to the calculations command,…which allows you to blend two channels…to create a new alpha channel,…and we're going to use that command…to select this guy right here.…Now as you could see, he is set against a white background,…which makes him easier to select…than if he was against a very busy background for example.…

He's also bald so he's got a smooth head.…We don't have to worry about a lot of hair…but he does have a little bit of arm hair,…which is going to enter into the picture,…and he also has this fine string detail…inside of his tennis racket,…and so we're going to be better off…bringing two channels into the picture.…Now the first thing you want to do…is switch to the channels panel,…and see what you have to work with…by first clicking on the red channel.…