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How RGB Values are Created

Lesson 2 from: Working with Curves in Photoshop CC

Jesús Ramirez

How RGB Values are Created

Lesson 2 from: Working with Curves in Photoshop CC

Jesús Ramirez

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Lesson Info

2. How RGB Values are Created

Lesson Info

How RGB Values are Created

The first thing that I want to talk about is how RGB images are created. Ah, photo and a computer is made up of pixels. Pixels are is short for picture elements and their tiny little squares, and you probably have seen them before. If you're working in photo shopping, you zoom in past 600%. You can see the pixel grid. There it is in those tiny little squares, those air pixels, and that's what makes up your image and just the screen. Each pick, so has a specific are GV value between zero and 2 55 This valley of the tournament determines the color that the pixel is RG V stands for red, green and blue. And that's gonna be really important throughout this class because everything that we do is gonna relate back to the RGB values. So actually, I think I skip ahead. So we talked about pixels. Then we know that an image is made up of all these tiny little squares called pixels, and they have an RGB value now are GV. What is that? That is the color mode that you see in digital images, whether ...

it's Web, your cellphone, anything digital Sergey V that is an additive color mode. That means that use three lights to create all the colors that you see Use a red light green light in the blue light. The absence of all lights creates black. The presence of all lights creates white, as you can see here you have these three circles of each individual color, and right in the center we have white. That means that when you put all the lights together, you get white. You can think of it as a projector. If you've ever seen a projector, you probably look into it. You can sort of see the red green lights coming through, and when all the lights hit the wall, it creates a white light. So that's the same thing that's happening here and excuse me. And one thing that is really important is to think about the other side of the opposite colors of that, and that usually is in the C m. Y que color mode the science magenta, yellow and keep. A lot of people think it's black. It's actually not black is the case stands for key, and those are the up that is the opposite of RGB. And that's also going to be really important when we started color correcting images. Because when you have the red light, we can either increase the red or reduce it. If we increase that, we get more red, of course, but if we reduce it, we start introducing the opposite color the opposite color of red scion. The opposite color green is magenta. The opposite color of blue is yellow. All you really need to remember is rgb c m y que. And if you forget what the opposite of each color is, you can go into a window info and the info panel you see here RGB Just look right across that read scion green, magenta, blue and yellow and is in a lot of places In photo shop. You can also create something like a, um, selective color adjustment layer. And if you make an adjustment, you reduce. I in it was actually let me get into the blacks here. If you If you reduce scion, you get red. If you increase, I hand, you obviously get saying, and obviously not in this case because we're in the blacks, but if ever to switch to maybe whites. You can see how now we add saying, The point is that that relationship is found everywhere in photo shop, so it's gonna become really, really important as we start color correcting images. Also, to drive the point. This point further, I'm gonna show you this image. Here's an image I shot in Venice, and we have a group called Argov in just a regular layer titled Venice, and you can see they're exactly the same. But if I open up the group, we have these three layers labelled red green blue background. The background is black. What I did there is sort of fake the light that creates the images in a photo shop. So if I over to select the red layer, I can click and drag it and move it away and notice that just those three layers with those three colors create that image and you can see all the colors. And what I'm really trying to duplicate in that group is what happens in the Channels panel. The Channels panel contains the Red Channel, the Green Channel in the Blue Channel. So that's exactly what that group was doing. Is putting the light of those three channels to create the image much like layer mask the channels reveal or high pixels based on the luminosity White reveals black conceals. So if I click on I'm currently in the Blue Channel So anything that is bright in this channel means that there's a lot of blue light coming through. If it's black, it means that there's less of that blue light coming through. And just to quickly show you, I'm gonna click and drag the channels panel to the side and I'm gonna create a curves adjustment layer. And we're gonna talk more about the curse adjustment layer of This is the first summit. You see it or you really don't know what I'm doing. Don't worry about it. I'm gonna explain it further. But for now, I'm going to go into the drop down that reveals the different channels and I'm gonna click on the Blue Channel and I'm just gonna click and drag up really, really high. You'll notice that the image I got really got brighter, but it also became a lot bluer. If I click on the Blue Channel, you will see now that that channel is really, really bright. That means it's a lot of blood. Uh uh, Blue light coming through. If I adjust the Blue channel again and reduce the blue light, that channel becomes starker. Once again, black and dark pixels were stopping that light from coming through. We already know that that blue has an opposite color, which is yellow. So if I enable the image back again, you'll see that the image now has a yellow tent to it. So just with that knowledge along alone, you can start realizing that you can color correct images that have color caste, and you can also apply creative color corrections. Teoh, create a color grader or color tent to your photos, and that's what we're gonna talk about. We're gonna expand on that principle and make it. Ah, and I'm gonna show you how you can do it, obviously more creatively than just clicking and dragging these points. But, um, that is gonna be the basics of this class. So let me continue on into the next, um, slight here. So So, Yeah, so now we're gonna talk about, um, continue talking about curbs, and there's really two ways in which you can apply curbs. You can go into the image menu, then go into adjustments in click on curves, and then you can make your curves adjustment. Now that creates I made on extreme effective so they could see how it works. But the problem with going into image adjustments and then selecting curves is that you're making a destructive effect. If I want to go back and edit it, I really can't do that. If I go back into image adjustment and curves, you'll notice that the curve is straight. Aiken make another adjustment, but now I'm building on top of the previous adjustment, so I'm destroying pixels. If I work that way, it's a lot better to instead and by the way, just hit command options E to undo that's controlled. Busy on the Mac on the PC. Excuse me? It's a better way of working as working on destructively, and you can work understood clearly in two ways. You can create a smart object by right clicking on it, selecting convert to smart object. You can then go into image adjustment curves, and you can apply your curves adjustment and you'll notice now that we have these little um labels here at the bottom. We have something that says smart filter curves and then this letter, like on here. If I double click on the label that reads curves, I can bring up the curbs panel once again, and I can make an adjustment and refine whatever I just meant I made. I can also click on this tiny little icon here on the right hand side. If I double click on it, it brings up the fade command, and you can reduce the opacity. Or you can change the blending mode. We're gonna talk more about blending months in a moment, but ah, blending mode is an algorithm that you apply to a layer so that it blends with the layer below it in a certain way. That's, Ah, one way of working with curves. But the way that we're gonna work in this class in the way that I generally prefer working with curves is using the curves adjustment layer this tiny little icon down here that have filled circle. If I click on it, I can select curves, and that creates an adjustment layer and adjustment layer affects all the layers below it, in this case, the Venice layer and everything below that, if I want it so that it Onley effects of Venice layer. I can create something called a clipping mask so I can click on that icon right there that square with the down pointing arrow. So if I click on that square, you'll notice that the curves adjustment layer now has a down pointing our arrow right next to it. That means that this curves adjustment layer will only affect that layer and nothing else below it. And I don't really need in this case. I'm just going to click on on that and just disable it. And if I make an adjustment, I can come back, work in another layer, and at any point I can come back, click in the adjustment layer and then refine it just like I could with the smart object. But I I just prefer using layers. We have a layer mask that we can paint on with a layer mask. You can paint with black to hide the effect, or you campaign with white, and I'm selecting the colors here from my foreground and background colors right here on the left, on the bottom left. And if I paint with white reveal the adjustments, and at any point, I can come back and make edits to that adjustment layer. So that's the way that I prefer working with with curves. Someone had delete this layer, and now we're just gonna do an overview of the properties panel when you're working with any one of these adjustment layers, if they have any properties, they will appear in the properties panel, which is right up here for me. If you don't see the properties panel on your screen, you can goingto window and make sure that property says That's chuck Bucks right next to it, and that will bring up the properties panel. If it's floating somewhere, you can just click and drag it over onto the panels. When you see the blue outline you can just release in, it'll snap right on there, and that's usually where I like to keep it. And as I said when you could create any adjustment layer in this case of curves adjustment layer, the options for that adjustment layer will appear on the properties panel, and before we talk about it any further, we're gonna go into the options so that we could um oops. Sorry about that. So that we could make sure that we're looking at the same thing. So if I go into curves display options, I'm gonna be working with light, which is sort of we talked about earlier. RGB we're not gonna be talking about pigment. Um, you should leave if if anybody's using adobe light room, the curbs panels actually percentage and ink. So when you hover over it and let me cancel this, you could see um see how I'm hovering over the curves here. And there's a percentage input of 24% and output of 25%. That's ah, percentage. That's not what we want. We want light that goes from 0 to 2 55 the, um rgb values. And I'm gonna enable all these strict boxes so that we could see the different overlays. And I'm gonna talk about what they are in a moment. Make sure that the quarter tone check the quarter tone icon is selected. Not this one that has increments of 10. I want the one that's quarters because we have our whites quarter tones, mid tones, 3/4 tones and blacks. And then I'm gonna press OK, so that's how how we're gonna be working with the properties panel also has presets, so I can select any one of these presets toe apply to our image. For example, we might want to give this image a little bit more contrast or even more than that, a stronger contrast or we can apply special effect like color negative. Are we going to start with default and make our own adjustments? We also can select each individual channel and adjusted independently. You saw that a little earlier. We can select the Red Channel and make adjustments just to that individual channel. You have this icon right here, which is the X election. You can just click on a point and you can hover over the image and you'll see that circle going up and down the curve. You can click, and that's where that value resides on your image, and then I can adjust it. Use and use that the using the down or up arrow keys on the keyboard. Or I can just click and drag from the image so you can do those two things to create a point in adjusted

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Ratings and Reviews

user-7963ec
 

This is a terrific course. I am an intermediate Photoshop user. I really learned a lot about understanding the use of curves for different situations but Jesus provided an excellent base of knowledge about color modes, color interactions, histograms, and blend modes. I have heard all of these topics discussed before but now i feel like i actually understand the technical aspects so that i can make decisions, not just memorize formulas. Superb. Thank you.

artmaltman
 

This class is fantastic. Teacher has a great depth of knowledge and explains very clearly with great examples. Well paced, well organized and very clear. I had no idea how much power "curves" have, and now I know. Very highly recommended.

Tomas Verver
 

Good course from an engaging teacher abou the curveseffect. Showing lots of examples what you can do with effect. A nice course about a specific subject! If you need a more general course and have limit amount of resources this one might not for your. If you would like a course that goes into detail this one is a nice to have. Projectfiles are included.

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