Lessons
Lesson Info
Selections With Channel Pull
Remember I showed you the color range. There's another way of working in here, and it's used a lot in the visual effects industry. And that is a channels based selection, affectionately known as a channel pull. And because we have three different colors that make up this image, if we look at this image it's RGB. Red, green, blue, and we select the red, this is looking at just the reds in this photograph. Now the whiter areas mean there's more red, and then where those areas are darker means there's less red. So this is the reds in the photo. This is the greens in the photo. And this is the blues in the photo. So I don't know about you, but I kind of feel like this, might be a better starting place than this. 'Cause reds, eh, greens, eh, and blue, boom look at that. Look at the big separation, 'cause there's practically no blue, in that tree and in the grass there. So what we wanna do now, is we just wanna do exactly the same thing before. 'Member when I showed you how to choke the mask...
? We can do the same thing from a channel. And this a quick way to get a real fast selection. So we're just gonna go in here, we're gonna grab the blue. I don't wanna change the blue, 'cause if I change the blue, I'll show you. I wanna show you what's gonna happen. 'Cause I always hear people say, what happens if? Well, this is what happens if. You know it gets kinda weird. You know it's gonna start you know, doing weird things to the colors. So we don't wanna be making our selection from the blue channel. What we wanna do is duplicate the blue channel. 'Cause we like the information we got from the blue channel, but we don't wanna mess with this 'cause that's gonna miss other colors. So let's keep our colors intact and all we wanna do is create a nice mask out of this blue channel. So we get a blue copy which is same thing as we did with the quick mask, sort of. All it's doing is looking at the black and white information, and then we just wanna add a little bit to it, so we're gonna go into control, or command L for levels. There's our levels here. Just like what we did before. Let's start in our mids. And let's not be as aggressive as we were last time. The blacks, notice it, as I'm pulling in the black, see the grass? Those little areas we just kinda cleaning those up. Nice. And then we're going to go into whites, we're gonna clean that up. Let's just move it over. And then we've got, pretty decent starting place. There's a little bit we missed in the bottom, but I would rather miss that bit at the bottom there, than crunch this right up. If I crunch it too much we're gonna lose it. A lot of things hide edges, you can go all the way in there, and you just got your area there. So once we've done that, we just simply click OK. And we're just gonna control click on it, right? So what we've done, with right control click, we have now copied the blue channel, because we like the informations in our separation. Then we use levels, to choke the mask, in other words to push the whites in, push the blacks and get rid of all the little spots, and then we use the gray to kind of tune it, to get a nice black and white mask. So this is a mask right now. And it is in the channels. That's exactly what you get when you get a layer mask, same thing. So this is a good starting place, so I wanna load this selection now. So the way to load the selection, is to control click, and remember when we talked about select and we could load selection? It's gonna be there too, it's blue copy. See that? So these tools work the same, click OK. So if you can't remember to control click on there, maybe you're thinkin' of shift click, you can't remember, you can load it up under the select menu, same thing. So now we've loaded the selection there, right? So what's happened though, is if you look at this, notice we've selected the background because of selecting the lighter areas which are the white areas. We wanna invert the selection or inverse, what it's called. Inverse is a selection, it's like an invert with an S. So when you work with a selection you inverse it, when you invert the colors it's an invert. So if we just go under select, inverse. And of course there's a keyboard shortcut. Command+shift+i or control+shift+i, depending on whether you're on MAC or Windows. Now we've selected our tree, and all that stuff. We can go back up into RGB. Notice it looks really weird. You've gotta click RGB before you go back to the layers. It looks weird because the mask is on. So we just hide the mask, and oh it looks normal now. Okay, cool, I know what we're doing here. Back in our layer, make sure everything is right. Make sure we select RGB. You see when I went to the layers it looked weird. Let me show you. If it's not selected right, you go back to layers. See how the layers panel's gonna have this weird color around it. If you see that, that's a clue that something is not normal. Go back here, make sure your RGB is selected and the mask is turned off. Notice the selection's active. So we don't need the mask right now we just used it for the selection. And then we go into those layers there, and there we go. So we can hit the Q key, for quick mask. See that? And then that enables us to go in and do all, let me show you. Okay there we go, the channels, there's our quick mask, see that? If we hide those, look at that, the quick mask looks very much like this, but it's inverted, see that? So all that is is an inversion of the same thing. So the reason I did it this way, is so I can just get a white brush, and just quickly paint across the bottom here. Just clean that up a little bit. Here I have a Wacom Tablet and I'm not using it. Go in there so it's like that. By the way, you guys all use these? Best tool ever. Wacom Tablet. Because what it does is it enables you to use a pen, it's just a lot easier to use than a track pad, but the main thing I love about this is because this is the one way that you could actually vary the amount of pressure you have, so generally speaking if you don't use this and you're using just a mouse, you're working with a marker. But if you wanna do shading like you would with a pencil or something like that, then I use this. And this is great for retouching and stuff like that. Now I'm not paid by Wacom or sponsored by Wacom, I just think it's a great tool. Anyway, so now we've done that, we've cleaned up that selection there. Looks great. Let's hit the Q key. Go back to our layers and of course we hid the mask, look at that, we've nicely masked out the tree. Notice we got a better result, doing it that way with a channel pull. And once again it was one of those things that doesn't take very long to do. You know if I'm not demonstrating that.
Ratings and Reviews
JUAN SOL
Thanks, Colin, for this great course. It's always interesting to get better knowledge about selections, specially for dummys like me!