Editing an Image Using Curves
So let me show you how to think about curves by working on some images and when we do, we're gonna end up using adjustment layers because that's when they become, well curves, becomes dramatically more useful. So just in case you haven't used an adjustment layer, let me introduce those to you first. Then we'll start learning about how to think about curves and apply it to images and I think that's when you'll get excited about what it offers. So in my layers panel, I'll go to the bottom, I'll click on the adjustment layer icon and I'm going to choose not curves right now, just because I wanna talk about adjustment layers first, I'm gonna choose a choice called black and white which should take all the color out of my picture. I'm just choosing an adjustment that's obvious. Then, this is an adjustment layer. It's an adjustment, sitting in its own layer and it's as if you're standing at the top of the layers panel looking down and you're looking through the adjustment layer and it is cha...
nging your view of what's underneath. In this case, it's a black and white adjustment layer, so as you look through it, the color information that's found underneath can't be seen because it's absorbing all that color. Well when you have an adjustment layer like that, remember I went to this icon, half black and half white circle to create it, you also get a mask, which is this white box. And we have a separate lesson about layer masks, which is what this is, and so if you haven't seen that lesson, you might wanna look for it. It's part of the complete guide. And I'm gonna come here and grab my paintbrush tool. Since we already have white in the mask, I'm gonna switch the color I'm painting with to make sure it's black. There's a little double arrow here I can click on to do that. And now wherever I paint with black, it's gonna remove my adjustment. And so therefore, the image will come back to full color. So I'm gonna come in here and just paint where I want your eye to look. And if I release my mouse button and you look in the layers panel, you'll see the black paint that I'm applying. It's only showing up in the layers panel when I release the mouse button 'cause it just is trying to make sure Photoshop is speedy when I'm painting and that it's not trying to update things which could slow it down. So, here I'll let go again and you'll see the layers panel update. But, when I paint with black, the main thing is is I'm removing the adjustment, preventing it from apply wherever it is I'm painting. And therefore, I can only get it in certain areas of my picture. And so, we're gonna end up using adjustment layers when we're applying curves because then afterwards, I can paint with black to indicate where I don't want it to be applied. And so, I'm gonna remove this adjustment layer by dragging it to the trash. I just clicked on its name and I drag it to the trash. And let's start using curves and see what we can do with this picture. And we can also, if you'd like, use brightness and contrast and levels because they're also available as adjustment layers. So, for instance, brightness and contrast, what I would like to do is darken this are right here. Well in brightness and contrast, how do I do that? I have a brightness control and when I move it, it darkens everything, it doesn't allow me to target this area to be specifically precise about it. Or, I would like to make this area, the difference in brightness between that area and the area that's behind it in space, more similar to each other. That would be lowering the contrast between those two areas. I do have a contrast control here in brightness and contrast, the problem with it is it thinks the difference between a bright area and a dark area is 50% gray. Anything brighter than that is considered a bright area, anything darker than that is considered a dark area. Well, what if this area and this area were both darker than 50% gray? Well, if that was the case, I don't think it is, but if it was, adjusting contrast would cause both of those areas to brighten or darken. The main thing is I don't have any control here to say how can I get those two areas more similar? And the same is true if I throw away this adjustment layer, and I come in here and use levels. In levels, how do I tell it to darken this and brighten that specifically? I have a slider over here on the right, which will brighten everything, force more areas to white. I got the middle one, which will brighten and darken everything, but the relationship between those two areas will remain the same. Let's throw that away. It's only when you get into curves that suddenly you have control. The key though to using curves is to always have this little hand icon turned on. You can just click on it and as long as it's got a dark background, it's turned on, but I use it every single time I use curves. So, if you go to the upper right of curves, there's a little side menu you can access right here. And one of the choices in there is auto select targeted adjustment tool, that's what the hand is called. It's the targeted adjustment tool. So if I turn that on, now if I go back to the side menu, you'll find a checkbox next to it to indicate it's on. That means every single time I ever get into curves, the hand icon will be turned on automatically. What the hand icon does is if it wasn't turned on, then you could have whatever tool you previously were using over here in your tools panel active. And if you moved your mouse on top of your image, that's what it would be thinking about. Clicking on that icon means let's deselect whatever tool was previously active in our tools panel so that now we have something specific to curves active. And now you come out here into the image and I want this to be more similar to that in brightness. Well all I gotta do is move my mouse over this area. If you look in curves, you see a circle, and that circle's moving if I move my mouse around. Well that indicates exactly how much light is in this area. And if I click the mouse button, watch what happens to that circle. It just turned into a little dot. That's like adding a dimmer switch on your wall that's gonna control how bright that area is where my mouse is. I'm gonna also move my mouse to the darker area behind and I'm gonna click and now I have the equivalent to two dimmer switches. Those dimmer switches are telling me how much light was in those two areas. And so, if I come in here and look, you can tell that one area was brighter 'cause this is higher. It's like in your kitchen, havin' the dimmer switch turned really high, just not all the way as high as it could go. Then in the other areas you see less light because its dimmer switch is lower. Well all I need to do to get those two areas to look identical is to get those two dots to be the exact same height. And if I were to move this dot up to get there, it's like taking a dimmer switch and movin' it up, you're gonna brighten things. Or, I could take this dot instead and move it down to the same height as the other. Well if you take a dimmer switch and you move it down what happens? You use less light and things get darker. Or, I could meet somewhere half way. Move the upper one down and the lower one up. That's gonna make the bright areas get darker 'cause I'm movin' its dimmer switch down, and the darker areas get brighter. But it's your choice, just look at the image and say if you wanted those two areas to look more similar, would you do it by darkening this part, or brightening that? I think I'd darken this. So, I'm just gonna pull this down 'til it's the same height as the other. But then, we gotta just get rid of this little part here that loops down. So I'll add a third dot, try to get 'em. Now do you see that these areas are identical? It's not that that's what I needed, I wanted less of a difference between the two. I don't need them to be identical. So, let's put this back up there and I'll just watch it as I adjust to say okay, somewhere around there, they're starting to look more similar. All right, let's just start working on this image and I'll show you the way I think about curves in general. Most of the time in curves, if I wanna brighten or darken something, I use one dot. I click on the object that I wanna brighten or darken and I think in my mind, I have a dimmer switch. And I move it up if I wanna brighten, down if I wanna darken. When I do that though, the entirety of the curve is gonna move up or down and so, afterwards, I'll end up painting on the mask with black to say I don't want it to affect these areas. And therefore I can limit what part of the image we're working on. If, on the other hand, I want detail to pop out of the image, not just brighten or darken something, but have detail jump out, then I'm gonna be adding two dots on my curve. I'll look at whatever object it is that I'd like the detail to pop out on and I'll add one dot on the bright part of that object and one dot on the dark part of that object. And then I'm gonna make them more dramatically different in height. So, let's see how that works. So first, I wanna brighten something. If you look on the right side of this photograph, you see one little bitty chick over there all by itself. Well, I want it to be brighter than it currently is. So I'll go over here and do curves adjustment layer. That hand tool is turned on automatically because we have auto select target adjustment tool turned on. I'm just gonna come right over to it, I'm gonna click, and now it's like I have a dimmer switch in my hand, I'm gonna pull it straight up, I'm ignoring the rest of the picture, just looking at that chick, and bringing it up until I like its brightness. Let's say right about there. But now, if you look at the curve we're ending up with, you see a dot that was added to the curve right here. That's the dot I added. It's working on whatever was this brightness level and it's brightening it up. But the rest of the curve changed along with it. So now I grab my paintbrush tool, and I'm gonna paint with black wherever I didnt' want that to happen. So, wherever I paint with black, the image goes back and in fact, I'm gonna paint across the entire picture because then, I can just zoom up on the chick and paint with white because white's what allows the adjustment to apply and then I can come in and just say okay wherever I paint here, where it should apply, and I can get it exactly how I'd like. Now I'm not gonna be as precise as I usually would be with painting 'cause that just takes more time, and I want you to learn about curves instead of just learning that I'm a good painter. We'll zoom out, Command Zero for zoom out, Control Zero in Windows. Now, if that's too bright, now that I've painted it in, all I have to do is either go here in curves and grab the dot that's already there and pull it straight up and down. It's a dimmer switch so it works just like a dimmer at home. There we go. And then if I turn off the eyeball for the adjustment layer, here's before, there's after. And the other way I could've lessened this is instead of adjusting the curve that's here, I could lower the opacity of the adjustment layer. This means how strong is the adjustment gonna be when it's at a hundred percent, I get a hundred percent of what I dialed in. And when it's less, then you get less than what you asked for. So I could've lowered the opacity instead. Now let's work on other areas. In this case, I now want your attention to go over here. And I'm gonna do that by making the detail that is in this guy jump out. Usually the way you make the detail in something jump out, is you get a greater difference between the bright and dark areas. So, I'm gonna do a new curves adjustment layer. That hand tool is turned on and I'm gonna click on two parts of this. I'm gonna look for which area do I want the detail to pop out in and I'm thinkin' about kinda this area. So I'm gonna add two dots, one for the dark part of that area, oh and I didn't mean to get what I just did. I accidentally had two fingers on my track pad, which made it have a little dialogue pop up. And then I'm gonna go for the bright area. So now I have two dots, those are two dimmer switches. And I just wanna make the difference in height between the two more dramatic. If I move the upper of the two dots straight up, that's gonna take the brighter area and brighten it more. Ignore everything except for the bird. Then if I want to, I don't have to, but if I want to, I could take the dark area and bring it down to make it even darker, but I don't think that's gonna help. It's dark enough. Then, I didn't want that to affect the entire picture, so I'm going to fill this mask with black to say get it off my picture 'cause any part of the layer mask that's black prevents the adjustment from applying. One way of getting a mask that's already existing to turn black is to choose this command. That makes a negative out of something, so if it used to be white, it'll be black, and if it used to be black, it will be white. And now I grab my paintbrush, painting with white, and I paint in the change wherever it is I want it. So I wanted your eye to be drawn right over in here, and so I'll paint that in, I can bring it up here too, it'll probably work fine. You just gotta be careful, right now I have a soft edge brush and if I get too close to the edge of the picture, or use too large of a brush, I'll get a little glow around him. So I just need to be precise with where I paint. I'm gonna hide this adjustment layer by turning off it's eyeball. There's before, turn it back on, there's after. Do you see the detail just pop out of that thing? How did I do that? Anytime I want the detail to pop out, I add two dots to my curve. I look at whatever object it is or area where I want the detail to pop, and I add a dot for the darkest part of that and another dot for the brightest. And I'll get two dots. Then I'm gonna make it more dramatically different in brightness and if you move the upper dot up, you're gonna brighten that part, move the lower dot down, and you're gonna darken that part. Depends on the picture as far as what should be done, just look at the image and say, would this thing need to be darkened or would it need to be brightened? And if I glance at it, it's dark enough in the dark areas, there was no need to move anything down. All right, then there's a chick over here on the side. My eye goes to it and I don't want it to. I wanna make it harder to see that, make it harder to see the detail. So I'm gonna create a curves adjustment layer and we're gonna do the opposite of what we did to the main character in here. I'm gonna add two dots again. One to the dark area of that object, one to the bright area of the object, and I'm now gonna make them more similar to each other. That means we have two dots, the higher dot is for the brighter area, the lower dot is for the darker area, and I wanna get 'em closer to the same height. If I made it exactly the same height, we'd just have a gray area, we wouldn't have any variation. So I look at this little guy, the chick there, and I say would I like to darken it or brighten it to accomplish this? I don't think I need to darken it, it's already close to black in the darkest areas. So it's the bright areas that I wanna darken up, that means go for the higher dot. Higher means more light, remember it's like a dimmer switch? So grab that higher dot, just pull it straight down. If I move it to the left or right at all, it's by accident. That would be like going in your kitchen and grabbin' for the light switch that controls the light above your sink and you accidentally grab the one for the hallway, you're not gonna get what you expected. You always wanna add a dot and if you're gonna move it, most of the time you move it straight up or down. So I've done that, I don't want it to affect the entire picture, so I want the mask to turn black so it doesn't apply anywhere. I use this command right here so often that I use the keyboard shortcut, Command I on the Mac, Control I in Windows, I'm gonna type that and that means invert. Then I would grab my paint brush and I'm gonna paint right on that guy and if I hide the adjustment layer, here's before, see how he jumped out, there's after, now he's kinda disappearing, and it's just a little too much. I could either back off on the curves adjustment or go up here to my opacity slider and lower it to lessen the effect. Good enough. But what we're doing here is we're adding contrast if we make it steeper between two dots, then we're reducing contrast if we're making them similar in height. But unlike using brightness and contrast, the adjustment, with brightness and contrast, it's thinking about specific brightness levels all the time. Like 25% gray is a, let's say highlight, and 75% gray is a shadow. And you can't have it deviate from those. But here, we get to plug in exactly what should be brightened and exactly what should be darkened. So we look at an object and we say let's look at the bright area of it and the dark area, add dots for it. Then either make it steeper between the two to make the detail pop out, or make it more similar to make it harder to see the detail. So, lots of things I could do here. I wanna darken the road that's in the distance. So, curves adjustment layer. And if it's just darkening, one dot's fine. Just one dot, pull straight down. Then I don't want it to apply to the entire image, so I type Command I, remember that's invert, Control I in Windows, I grab my brush and if I paint with white, I can paint in the change and I can darken up that road. You just have to be careful with your painting which I'm not doing right now because I'm trying to get you to learn about curves, not about how to paint. But, now if I hide that adjustment, turn it back on, you can see the darkening effect. And I could just be more careful with my painting to be better at it. So, there's all sorts of things we can do with curves. But, it's my favorite adjustment, it does take awhile to get used to, but I think it's really worth it.