Making a first-pass calculation

Now the images that we've seen so far presented us with certain challenges, but it gets worse.…So I want you to have a sense for what you do when you have to hunker down with…a really tough image, like this one here for example.…We have this woman whose hair is sometimes brighter than the background,…sometimes darker than the background.…Every once in a while we have this fraggy wispy details, other time we have…hairs that look likes it has product in it, and the hair is almost…invariably the exact same Hue as the background, with the exception of this…lower left region which happens to be the toughest area to mask, because the…luminance levels are so close to each other, and then we this someone out of…focus earrings and so forth, and we'll ultimately mask her against this background here.…

Now I consider this to be a pretty darn successful composite, we have lost some…hair over in this lower right region, but we're managing to keep all kinds of…wispy details at the top, we've got some lovely details over here on the…