Hey guys this is Eric from Final Cut Studio School and I’m here to how to show you how to build a key from scratch. Now, we have key light in Primatte and Chroma Key and all that good stuff, but those are kind of canned effects, you know, why you can build keys from scratch just like you can build blurs from scratch or anything else.
So, I want to show you how to build a little key from scratch and I’m not going to despill this, I’m not going to color correct this or anything, I’m just going to show you how to build this key. This footage looks simple, but let me tell you what, I’ve been doing this a long time and for some reason, this footage is hard to key with a single key. It’s going to take multiple keys to key this and because of this glass here, that’s transparent and it’s a tough key even though it don’t look like it. So, I’m not going to worry about getting into it making this key perfect. I just want to show you how to build a key using other nodes besides using the Keylight and Primatte.
So, let’s get started. The first thing that I’m going to do is I’m going to branch off a color, go to my color tab. I want to branch off a color replace, okay. Now, when I do this, it brings up my color replace parameters. Now, it gives me the option to affect my alpha channel and I want to do that if I’m using this as a key. So, I’m going to turn that on, okay.
Now, my source color wants me to pick my source color. I’m going to click my source color and I’m going to come over here and click my background to the color I want to key out in. Give an average there, okay. Now, my replace color, I’m going to go to my color picker here and just choose black, boom. Now, you can see what happened here.
Now, this is also a great way just to pull a matte for something. Now, we can go into here and we can adjust our hue range or hue fall off like this and we can go in here and fiddle with it, the best of what you know, just trying to make it rough matte here. I’m not worrying about all of the spill and stuff like that as of yet. Now, see if we hit the A key, you can see we have alpha channel and you can go in and be as picky with this or solid as this as you want, it’s really up to you. I’m not going to work too much on this here. Like I said, I don’t want it to be too bad, but you get the point and I’m sure you don’t want to sit here and watch me for this, until I get it completely perfect. So, let me up this a little bit, this will be good right there, just for a rough view.
Okay, now we have this color replace. I’ll go back to my color channel. Now, I want to go back up here to my original footage and branch off a SwitchMatte. Go to layer, SwitchMatte, branch. Now, this will branch off our SwitchMatte. So, what I’m going to do is I’m going to take my color replace and put it into my SwitchMatte, go to my SwitchMatte and invert the matte. As you can see, there’s an InvertMatte option, boom. And now we have this key, rough key or matte.
So now, we can take our SwitchMatte, go to layer, add Over and top in our background. Now, we have our background. And now, you can go in and adjust your hue fall off and saturation range, all that good stuff.
Now, what I’m suggesting is you know to make this perfect. I’m going to have to go in and pull a separate key on the head. I’m going to have a pull a separate key on the glass and I just ain’t got time for this, I just wanted to basically show you a quick rundown of building a Chroma Key from scratch. And this is the tree right here, very simple stuff; color replace into a SwitchMatte, into an over node.
So, if you’re going to try to make an alpha or a matte from scratch or you just want to have to go at it and see if you can build your own key. Now, this is not Keylight, this is not Primattte, this is just a cheap generic build from scratch Chroma Key. So, I really hope this quick tip has helped and we’ll see you guys next time.
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