From the course: Creating a Short Film: 09 VFX Environments

Intro to keying: Keylight

we're going to take a deeper look into one of the most foundational techniques compositing in visual effects, that of isolating a subject by removing its background. This process is usually referred to as keying, or pulling a key, and often involves removing a green or blue screen from behind a character to put the subject in a different environment So in this tutorial we're going to get a big overview of tips and techniques for getting rid of that green screen and also how to make your composites better. First let's look at the keying tools that I used on The Assurance. I used Adobe After Effects as my primary tool and the incredibly keying tool, Keylight, comes with it. So I used that a lot, of course. But I also used the Primatte keyer from Red Giant, that's part of their Keying Suite, which includes Primatte and also comes with a host of other tools for tweaking keys. And I found myself frequently using these extra tools in conjunction with both Keylight and Primatte. So remember as you're opening these exercise files, you're going to get warnings, if you don't have the Keying Suite, you'll get warning that you don't have edge blur, or matte feather easy, or something else that might pop up and that's what that's about. Now let's look at the basics of how these keyers work, I'm going to go the Effects and Presets panel, I'mma do a search for key-L, and once I put in key-L then I can get access to Keylight, it gets the Keylighter right here, it's in the Keying subfolder if you're, go up to the Effect menu, you go up to the Keying subfolder, it's in there. Now I'm going to go ahead and apply this to the assurance pocket version three layer, it's the one here that's red and unlocked. Again, yours might be named something a little bit differently, I'm working here with the original source, high res, high quality media here, and then I'm going to reconnect it to some lower quality media for the exercise files cause this file's just a little bit too big to download so yours again might be named something different and you might get slightly different results but it should be fairly similar. Okay so here we have Keylight, let's talk about this. The first thing we need to do is we need to pick the background color. So we need to go to the screen color which is the background here and I'm going to click the eyedropper tool to select our background. Now you don't want to just pick any color because even though this looks like the same green as this to our eyes, maybe, I mean to me it does, they look very similar; we really want the green that's around our subject the closest. So this actually is probably a little bit brighter than this green right here, and this is the green that we want and that's to get the best key. Now you don't want to go too close so you pick up some pixels, some of these feathered pixels, cause like right here's there's pick up some blur of this so we want to go kind of close to it, but not exactly on it, and that looks pretty good, so I'm going to go ahead and click that. Now, in a lot of software demos, this is where things stop. They say "Look, that's all you have to do, "you click a button and boom, the green screen's gone, "it's magic." And in reality that's not the case. There's actually a bunch of bad stuff going on here, I mean this is a pretty good result, it looks pretty awesome, there's a lot of fine details that made it through or whatever. But in order to really see what's going on here, we have to go over to the View menu and change this from the Final Result to Status. And that's going to really give us a more accurate representation of what's going on in our key. And this view here is a little bit kooky, but this is what you got to get used to as you're working with transparency and keying things out the Clip Black number, will be clipped to black. There's no gray in there. And same thing with white, is we take down this value, everything above the Clip White value will be clipped to white. So the strategy here with Keylight, with all the keyers, is that you want to be as gentle as you possibly can while still removing the background. So for example I'm going to take this Clip Black, very slowly, I'm going to move that up and maybe even not that much. It's okay if you have a little bit of gray, cause we can also mask out these corner areas, so you don't want to change your key and be more harsh than you need to for corner areas, because we can create something called a garbage map, which we'll look at in just a second. So a value of five might actually be pretty good here, and we probably want to get some detail back here and we probably want to get some detail back here in the copy of the Assurance that Korda'a's holding, in the copy of the Assurance that Korda'a's holding, so I might take down the Clip White value a little bit so I might take down the Clip White value a little bit and get a little bit of that white back. and get a little bit of that white back. And again, you don't want to go too overboard And again, you don't want to go too overboard because everything here is going to be clipped to pure white because everything here is going to be clipped to pure white and clipping can be not a great thing. and clipping can be not a great thing. So this looks like it's pretty good, So this looks like it's pretty good, this is the kind of look that you want with a key, this is the kind of look that you want with a key, where your subject is primarily white where your subject is primarily white and then the edges are gray and then the edges are gray and the background is primarily black. and the background is primarily black. So if we go back to Final Result, So if we go back to Final Result, we do have a lot of this motion blurred soft edge stuff, we do have a lot of this motion blurred soft edge stuff, this is great and juicy, this is great and juicy, and then we also have our subject here and then we also have our subject here and it's even doing a good job with this depth of field and it's even doing a good job with this depth of field which is not a good idea when you're keying, which is not a good idea when you're keying, you want to try and avoid that if you can. you want to try and avoid that if you can. But, even still, it's still getting the green out of there, But, even still, it's still getting the green out of there, it's looking pretty good. it's looking pretty good. Now let's talk briefly about some other parameters here. Now let's talk briefly about some other parameters here. If we, for example, the clip rollback, If we, for example, the clip rollback, if we take too much of this away, if we take too much of this away, like if our settings are a little bit too strong, like if our settings are a little bit too strong, we can adjust the Clip Rollback we can adjust the Clip Rollback to get a little bit more gray along the edges. to get a little bit more gray along the edges. I don't use that all the time, I don't use that all the time, but kind of like Screen Pre-blur, but kind of like Screen Pre-blur, and Screen Gain and Screen Balance, and Screen Gain and Screen Balance, it can come in handy every once in a while it can come in handy every once in a while while I'm tweaking stuff. while I'm tweaking stuff. I do often use Screen Shrink/Grow, and Screen Softness. I do often use Screen Shrink/Grow, and Screen Softness. What Shrink/Grow does, is if you take this What Shrink/Grow does, is if you take this to a negative value, to a negative value, you can see it kind of eroding the key you can see it kind of eroding the key you can see it's taking detail away, it's you can see it's taking detail away, it's pulling it in pulling it in and that gets rid of all these edge details. and that gets rid of all these edge details. We definitely don't want that here. We definitely don't want that here. You could also grow the key to add more details, and You could also grow the key to add more details, and so if I take this to a ridiculous value so if I take this to a ridiculous value you can see that it's kind of like you can see that it's kind of like taking in more information there. taking in more information there. I'm just going to leave this set to zero I'm just going to leave this set to zero 'cause our key's looking pretty good as is. 'cause our key's looking pretty good as is. We can also soften the edge of our key, We can also soften the edge of our key, sometimes if you have to be harsh with your key, sometimes if you have to be harsh with your key, especially with Clip Black, if you bring that up too much especially with Clip Black, if you bring that up too much you're going to get a really hard edge you're going to get a really hard edge that looks very fake. that looks very fake. And so you could add some Screen Softness then And so you could add some Screen Softness then to get some feathered edges. to get some feathered edges. You really want to, let's see, You really want to, let's see, if I zoom in really closely here if I zoom in really closely here and maybe put this into like full resolution and maybe put this into like full resolution or just auto resolution here, or just auto resolution here, we're going to see that these details right here we're going to see that these details right here like on her thumb, like on her thumb, there is a certain softness to the way there is a certain softness to the way that her thumb is right here. that her thumb is right here. So even this section of the clip So even this section of the clip that's supposed to be perfectly in focus, that's supposed to be perfectly in focus, isn't really razor-sharp. isn't really razor-sharp. So we don't want our keyed edge So we don't want our keyed edge to be any more sharp than this, to be any more sharp than this, 'cause then it'll look fake. 'cause then it'll look fake. Because cameras just tend to add a little bit of softness Because cameras just tend to add a little bit of softness especially if you're not working especially if you're not working at the Hollywood film level, at the Hollywood film level, if you're working with indie stuff like we are, if you're working with indie stuff like we are, there are some softer edges in here. there are some softer edges in here. So again, you want to try to work to make this edge So again, you want to try to work to make this edge as soft as this edge so it feels like it was shot as soft as this edge so it feels like it was shot with the same camera in that background. with the same camera in that background. So those are the basics of Keylight, So those are the basics of Keylight, and here's the final result that I came up with and here's the final result that I came up with once I got this color correction here once I got this color correction here I can turn on this Curves, I can turn on this Curves, put this in below Keylight so it's effected put this in below Keylight so it's effected and there's our final result there, looking pretty good. and there's our final result there, looking pretty good. And this is the one I did And this is the one I did taking a little bit more time with it, taking a little bit more time with it, looks very similar to this. looks very similar to this. Pretty easy shot to key, we had an even grain screen Pretty easy shot to key, we had an even grain screen for the most part for the most part and when you do that, shot fairly right, and when you do that, shot fairly right, then you get a good result then you get a good result and we got a lot of good soft details here and we got a lot of good soft details here it's looking nice. it's looking nice.

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