Create Realistic Chromatic Aberration in After Effects and Nuke

Music : [intro]
Joey Korenman : Hey there, Joey, here for school of motion in this lesson, we are going to take a look at chromatic aberration in both after effects and nuke. Now what the heck is chromatic aberration and why do I need to know about it? Well, chromatic aberration is one of those things that happens sometimes when you shoot photography, it's a real world artifact of the imperfectness of the lenses that we use on our cameras. And so adding it to CG renders can make them feel more photographed, which adds to the realism and also looks really cool. I'm going to show you some ways to achieve the effect without any third-party plugins. Don't forget to sign up for a free student account. So you can grab the project files from this lesson, as well as assets from any other lesson on the site. Now let's hop in and get started.
Joey Korenman : So what I want to show you guys today is how to achieve an effect called chromatic aberration. Um, and it's kind of a very technical name. Um, but what it means is that, um, sometimes if you're shooting something with a camera, uh, you know, depending on the quality of the lens, the quality of the camera, you may get an effect where the red, blue, and green parts of the image don't line up perfectly. Um, and I'm sure you all have seen this before. And it actually, when you use this effect, it, it almost makes your video feel like it came from the 1980s, because that was sort of the heyday of really crummy quality video. Um, so chromatic aberration is one of those effects that composite, or is a use to kind of beat up their perfect renders, right? You have is you have software like Maya and cinema 4d that gives you absolutely pixel perfect renders.
Joey Korenman : And that doesn't look real because we're not used to seeing things that are perfect because nothing in the real world is perfect. So we beat our footage up. And one of the ways we do that is by having the red, green, and blue channels, uh, get a little bit out of sync. So I'm going to show you how to do that first and after effects. So we've just got a pretty simple little scene here. And you guys all saw the preview of this when you started the video, right? So you've got one cube, it kind of turns, there's a missing frame there, don't worry about that. And then it fires out and you know, there's some, some cloned cubes and it's this cool composition, but I set this up, uh, specifically for this tutorial because you've got some very thin white lines, right? And then you've got red, green, and blue colors.
Joey Korenman : There's also some yellow, but, um, I wanted to show you a good example of, of a shot that would benefit from using chromatic aberration. So the first thing that you need to understand, and a lot of people who use after effects, don't really think in these terms, because one of the things I don't like about after effects is that it hides a lot of the technical stuff from you. It makes it a lot easier, but at the same time, um, it, it sort of, it's, it's kind of, you know, I don't know how to really put this, but it's sort of hiding things from you that if you knew they were there would, would give you more options with your composite, right? So one of the, one of those things is the fact that every image you bring into after effects has three channels, sometimes four, all right.
Joey Korenman : And if you see this little button right here, right, and you, and maybe you've all noticed it, but I bet most of you have never clicked it. If you click this, you can actually see the red, green, blue, and alpha channel on their own. So let's look at the red channel. All right, you see how my viewer now has this red line around it? Okay. So this is a black and white image obviously, but what this tells after effects is how much red is in each part of the image, right? So over here, it's black. So that means there's no red over here and over here, it's a lot brighter. So that means there's more red right there. Now let's switch to the green channel, uh, the hot key to do this, by the way. Cause I'm a huge fan of hotkeys is you hold option and you hit two for green, three for blue, one for red, four for alpha.