From the course: Nuke New Features Consolidated

Unlock this course with a free trial

Join today to access over 22,500 courses taught by industry experts.

Keylight: Adjusting alpha and despill bias

Keylight: Adjusting alpha and despill bias - Nuke Tutorial

From the course: Nuke New Features Consolidated

Start my 1-month free trial Buy for my team

Keylight: Adjusting alpha and despill bias

“

- [Instructor] Now let's take a look at bias. We'll start by looking at the alpha bias. We'll switch to this picture here, close that key light and open this one. The bias controls are right here and they're designed to cope with seriously discolored elements. I didn't have a green screen discolored badly enough to demonstrate this so I just borrowed the one from the Keylight tutorial. The first one we'll look at is the alpha bias. If we pull a key, we'll sample our image. Pull our key. Switch to the composite. Because of the serious red bias in the green screen, we got a terrible mat and semi-transparent composite. The way we tell Keylight about this red color bias is we turn on the alpha bias eyedropper and we do a sample in the foreground. There, much better. Now with Keylight, every one of these samples results in a single value. So if you sample different areas, you'll get different results. So you might look around for the best overall sample to use. Now we'll take a look at the…

Contents