Color and Luminosity Blend Modes
So color luminosity. The way I've got this diagram set up for you, it's showing you the difference between luminance and hue saturation in what we would call the separation of a pixel. So I'm basically separating the luminance value from the color value of a gradient, essentially. So the luminance value of that gradient, the darkness, the lightness and darkness of that and then the hue saturation or the color of that. So I'm gonna turn this layer on right here. And this layer is just a salmon colored layer that if I turn that to color, I have to select the right layer, we select this layer. Turn that to color, notice what happens. All of the underlying luminance value stays the same just like we talked about in that presentation. All of the underlying luminance value stays the same. We still have white, we still have black. And they are actually unchanged. They get no color data added to them. Pure white, pure black, no color added to it. But anything that's transitioning in between, i...
s gonna get a slight color cast or that salmon color cast that we put on the top. But also notice the colors at the bottom. When we set this to color, its overriding all the color in the image and saying hey, I know that you were green before, but now you're gonna be some version of salmon. If its a dark color, like if we turn this off, that blue, becomes a very dark salmon value. If we think about this in terms of the gradient map that we talked about before, remember how we talked about the gradient map, and the gradient map was our good black and white conversion that allowed us to target areas of, to target the colors in our image and make them lighter or darker based on their qualities. The same concept is happening here but applying color to it. So when we take the color of the salmon, and apply it to our entire image, this entire image, the luminance value stays the same. And all the colors take on the hue of that salmon color. So if we change this back to color, we can really control this really well. It doesn't seem like it but this is a really great way to do color gradient because we can take any color that we want, we can throw it over top of our image and we can just lower the opacity of that and get a nice subtle color cast over our image. So if I drop the opacity of this, we're still set to color, but if i change this to something like 50%, you see how, now, it is still taking it into consideration all the luminance value but its also allowing some of those colors underneath to mix with it. So think of this in terms of an artist with a palette, we're now adding a little bit of that blue to that salmon and mixing it together. We're adding a little bit of that yellow to that salmon and mixing it together. Because now we're set at 50%. Now on the flip side of that. If I change this to luminosity, look what happens. When we're placing all the luminance value with the luminance value of that color, which can be kind of hard to wrap your head around. Before when we put color on there, all of our luminance values underneath showed through, right? But when we changed this to luminance we're telling everything underneath there to take on the luminance characteristics of the color salmon. Therefore, we don't see white, we don't see black, we don't see mid tones. They all become whatever that color is. If we were to change this color, if we were to just get a brush and maybe change this with blue and brush this whole thing with blue, see the difference now. Blue's a darker color than that salmon was, change this back to normal. It's all blue. When we change this to luminosity, everything is taking on the luminance value of that color. So this is why I don't typically color grade with the luminance blend mode. The luminance blend mode is something I would reserve for our curves adjustment layer. Like I said before when we were talking about curves and how the luminance blend mode can be a great way to separate or the luminosity blend mode, sorry, the luminosity blend mode can be a great way to separate the color that's happening with that curves adjustment layer from the luminance that's happening with that adjustment layer. So let's go and take a look at a little bit of a a practical application of this one. So, let me go ahead and just add a solid color fill. This is typically, this is my favorite way to color grade between the solid color fill and the gradient map, these two are awesome for color grading. And we'll just change this to a let's say a orange-ish color, like that, orange-ish brown color. If I change this blend mode to color, notice how all of the luminance values of this image start to show through that color pretty well. If I drop this opacity down, something like 28%, doesn't that give a nice little color grade? Anyone watch a lot of tv in here, I know I do with my wife (laughs) The color grading, happens on everything that you watch, specifically things that have very good production quality. Movies, anything you go watch at the movie theater, will typically be color graded because you've probably done this, you've probably maybe gone to Olympic National Park, you take a video of it. You're like, aw this place is so gorgeous, you're taking a video of it and you get home and you plug it in and you look at your video and you're like man, this is nothing like that travel video I saw. Well, its the same data, essentially you're both taking in the same data when you record that data right? The only difference that's separating your video from their video might be the fact that they color graded things to make you feel something when you looked at it. And that's what we do with color grading. We wanna make the viewer feel something. We wanna transition that emotion into them and if we ... The perfect example of this is like my mom, God love her, she's a photographer, she got me into photography and she has been probably been taking pictures for, I hope she's not watching this (laughs) she's probably been taking pictures for you know, 20, 30 years, she goes on a lot of different photo excursions, she takes pictures of all of her different travels. She brings 'em home, she's says, check out these pictures, check out these pictures. And she's got a really good eye. But the transition that she's missing right there is the difference between having a good eye and being able to make me feel what you felt when you were there and that's what color grading does. And that's what we wanna do with color grading. So if you wanna just a cheat sheet, color fill layer, set to color, drop it to anywhere between 15% 25% opacity and now you can start manipulating the viewer to feel something. Perfect example, let's turn this layer off. This is the normal photo. Turn this layer on, it starts to feel more like what I thought Paris was gonna look like. I thought Paris was sepia toned (laughs) its not, apparently (laughs) so but this is that look and feel you get from movies that you watch that are filmed in Paris. If I double click on this color fill layer, that's why I say use a color fill layer, it's not permanent and because its adjustment layer, it has no bounds. It goes all over the place and you can change it at any time. It's a calculation layer. So let's change the calculation a little bit. Double click this, change it to something like a blue color. Now everything feels a little bit colder. You as the viewer, probably wouldn't appreciate this image, as much as you would appreciate the one before. Why is that? Its because I'm using color to make you feel something and in using these things in conjunction with these apps or these applications that we're talking about with, you know, opacity and fill and color, now we're starting to take just a regular color fill layer that before, before I learned all this stuff, I just said why would I ever fill my landscape image with a color? Oh I probably wouldn't until I jumped into some of the things that make that thing important. Now by itself, I just drop the opacity of this, yeah, I'm getting a color effect, right? But its not preserving what? Its not preserving my luminance, its not preserving the luminosity of the underlying layers. So I change this to color, watch how those blacks just come flying through. So its not just drop the opacity. Its drop the opacity and also bring in one of those blend modes with it, especially color. Soft light can do something very similar. If we bring up the opacity a little bit on soft light. Soft light makes light things lighter, dark things darker. That's all we talked about in terms of soft light. But also what soft light does, it takes into consideration those colors so because that color and that luminance value is on the lighter color area, its going to make the whole image a little bit lighter but also add a little bit of color to it too. So soft light can also be a really good way to color grade your image. You're just gonna have to increase the opacity a little bit. So that was soft light. That was color actually, let's take a look at how luminosity plays in. We talked about color already, let's talk about luminosity. So I'm gonna go ahead and grab a curves adjustment layer, which would be perfect for this image. And what I was telling you about before, if we pull this down, we're not just getting an increase or decrease in luminosity, right? We're getting increase and decrease in luminosity plus an increase and decrease in all of the colors because we're set to rgb, this is affecting the luminance values but its affecting the red, green and blue, not necessarily individually but all together. So there is going to be some type of color cast that comes along with that tonal adjustment. But if I change this blend mode to luminosity, now all we get is the luminance transition of that curve. We've separated all the color of it. We've stripped all the color out of that curves adjustment layer and saying no, you cannot affect the colors in my image. You're only job, and your priority right now, is to focus on the luminance values of my photograph. So I can make the darker areas darker, without introducing a color cast. If I bring this up to normal, we get a slight color cast. And it might not be something that you want. So if you're using Adobe Camera Raw, I really like Adobe Camera Raw and I think it has its place to make my images great before I come in to Photoshop but look at the curve at Adobe Camera Raw, can it separate the luminance values from the color values, no. All it can do is manipulate that curve. So there's certain things that when we jump into Photoshop and we realize, wow I'm getting access to things that I never even thought of. Some people call me like a pixel peeper (laughs) I don't really consider myself a pixel peeper 'cause I don't zoom in like this to peep at my pixels but, you know, if you wanna call that a pixel peeper, go right ahead. I like to say, unprecedented control over the process in images. I'm an artist, I want control over everything that happens in my images because now, I can control all the luminance values in here without a color cast. But, on the flip side, if I change this to color, any color data will come through and the luminance stays the same. So if you're color grading with the curves adjustment layer, so if we go and delete that, and delete that. We go in to see the reds, with this set to color, its gonna preserve all the underlying area but its going to make our shadow areas more cyan and its gonna make our highlight areas more red because its set to color, its allowing all the luminance values to remain the same. Again, now we're stripping that curves adjustment layer out. We're saying, okay now curves adjustment layer, let me through another wrench in you. You're not gonna affect the luminance values in my image, you're only going to affect the colors. So can you do that both on the same curves adjustment layer? No, you're gonna have to make two curves adjustment layers. One that will be set to luminosity, one that might be set to color. So don't just say, okay well Blake said color fill is the way to color grade. No, not necessarily because with this set to color, and I go in to say something like blue, I might be able to introduce some more blues or some more yellows into that also and create more of what we call like a cross process type of image, cross process coming from the days of film when we used to process a film in a set of chemicals that didn't belong to it. So, slide chemicals for analog film and so on and so forth. It kind of created this weird type of, it was used a lot in fashion, to get a different look for those images. And again, if we set that to luminosity, its going to allow us to adjust the luminance that are in the color blues that are in the image. So if this is set to, if we just change this entire curve, let's just go ahead and delete this and start with a whole new curve. Done a lot of work here. We'll just do another curve. If I were to change this to blue, and then change this to luminosity, we're now saying that blue is the only color that we're targeting or the blue channel, I should say, is the only color that we're targeting to get lighter and darker, and the yellows remain the same.
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Software Used: Adobe® Photoshop® CC® 2018