From the course: Deke's Techniques (2018-2021)

715 Contour map + arbitrary map

From the course: Deke's Techniques (2018-2021)

715 Contour map + arbitrary map

- [Instructor] In this movie, I'll show you how to combine a contour map as we're seeing here, along with an arbitrary map, which you achieve using a curves adjustment layer. And we'll also see how an arbitrary map compares to a gradient map, as we saw in the previous movie. Now the interesting thing about this is both of these effects are relying on exactly the same colors, as I'm gonna demonstrate in just a moment. However, we end up achieving a differently colored composition, and that's because arbitrary maps work on a channel by channel basis, whereas gradient maps affect the composite image. And a thing to note here is that gradient maps amount to a more modern approach. They're a lot more straightforward as well. Whereas gradient maps are old school, but they provide you with a little bit of additional flexibility. And we're actually gonna see how the two compare side by side. So I'm gonna go ahead and switch over to this gradient demo file right here, in which we have a black to white horizontal gradient on this bottom layer, and then we have this top layer which is that very gradient map that we assigned in the previous movie. All right, for the sake of comparison here, I'm gonna go up to the Image menu and choose the Duplicate command, and I'm gonna go ahead and call this Gradient arb map. And this is a very common abbreviation for arbitrary maps. All right, now I'll go ahead and click OK to create that file, and I'll press the Backspace key or the Delete key on the Mac to get rid of that layer, and we'll create a new adjustment layer by going up to the Layer menu, choosing New Adjustment Layer, and choosing Curves. And I'll just go ahead and call this guy arb map once again, and then I'll click OK. And that's gonna bring up the Properties panel. I'm gonna make that panel larger, so that I can see the entire curve. All right, now you want to switch from RGB to the Red channel. So we're gonna edit the Red channel independently, and I'm gonna go ahead and click on that top right point by the way. Notice the Input value is 255, which is white. I'm gonna change the Output value to 180. Now you might wonder why in the world I'm doing this. Obviously, I'm getting a blue effect here in the background. Let me demonstrate the method to my madness. I'll switch back to the Gradient demo file so we can see the gradient that I assigned using a gradient map adjustment layer. I'll click on it to bring up the Gradient Editor dialog box, and I'll double-click on this left most gradient stop in order to bring up the Color Picker dialog box. And I want to direct your attention to the RGB values. Notice that G is 255, so we don't need to map white in the white channel to anything different. It's going to be 255 as it is by default. Same with blue. But red, we need to make slightly different, and I just went ahead and rounded out the value. Instead of going with 178, I came up with 180. That's the big difference, and then I'll click OK. All right, now notice that this color stop has a location value of 80%. Well, if you whip out a calculator and you multiply .8, which is the same as 80%, times 255, which is white, you get 204. And so, at an Input value of 204, that's what that's gonna mean. Notice I'll double-click on that swatch. Blue is still gonna be 204. So it's gonna map to its default value. In other words we don't have to make any modification. Green however is going to be 153, but I took it down to 150 just for the sake of rounding things out. And then R, red, is going to be 100. Again just rounding out these values, and click OK. Now I'll select this guy. Its Location value is 50%. That is, a luminance level of 128. I'll go ahead and double-click on it. Notice blue is still 128, no different. Green is 64, and red is zero, and so I'll be dialing those values in to my curves adjustment layer in just a moment. Leave those guys alone, click OK. Go ahead and select this guy. Its location value is 20%. If you multiply .2, which is the same as 20%, by 255, white, you'll end up getting a luminance level of 51. So not surprisingly when I double-click on this guy, the blue value is 51. The green value is zero, and then the red value is 51. I'm gonna take it down to 50, just so we have more of a match here. And then I'll click OK and I'll click OK again in order to update that layer. All right, now let's go back to the arbitrary map in process. So this is advanced stuff not for the squeamish, but I do want you to have a sense for how it works. All right, so I'll switch back to the Red channel once again, and I will click right there, and I'm really looking for an input value of 200. So again, that's very close to that 80% Location value, and I'm gonna set the Output value to 100. How do I remember this from my gradient map that I just showed you? Well of course, I wrote the values down. All right, now I'll click right there, Input 128, that's exactly what I want. I'll go ahead and set the Output value to zero. So we're taking it all the way down to black inside the Red channel only. Then I'll click right about there, and we'll say the Input value is 50, so approximately the 20% Location value. Then I'll set the Output value to that same thing, 50. And now what we need to do is switch to the Green channel. Now I'll click right about there. I'm really looking for an Input value of 200, so that's approximately equal to a Location value of 80%. And I'll set the Output value to 150, so a little bit darker than by default. Click right about there, I'm looking for an Input value of 128, and I'll set the Output value to 64, and you can see we're already getting very similar results. And now I'll click here, and I want that Input value to be 50, and I'm gonna Tab over to the Output value and set it to zero. Now we don't need to make any changes to the Blue channel, because all those blue values were linear. In other words, we're not changing any of the default settings here. And then, I'll go ahead and hide the Properties panel, and now I want you to see how very similar these effects are. This is the arbitrary map, and this is the gradient map. So they're not absolutely identical, and we do have a little bit of banding by the way, but that's not going to affect the photograph. So once again, gradient map, here's the arbitrary map. Ever so slightly different, and yet this is going to affect the RGB photograph very differently, because after all, curves is working on a channel by channel basis. And so what I'm gonna do is right-click inside the image window using my Rectangular Marquee Tool, that's very important, and then I'll choose Duplicate Layer in order to bring up this dialog box right here. And I'm gonna change the document to that composition we created a couple of movies ago, which is Contour creature, by the way .psd, and I'll click OK, and now I'll switch over to that file, and you can see this is the effect. Now if you were to switch to the effect we achieved in the previous movie, you can see it's very different indeed. Well, part of that is that we have different settings associated with this file. And so let's go ahead and replay those settings by switching back to the file in progress. I'll click on the h lines layer right there and I'll change its blend mode from Overlay to Soft Light, as we did before. I'll select my arbitrary map layer, I'll change its blend mode to Color, as we did in the last movie. And then I need to darken up this background, and so I'll go up to the Layer menu, choose New Adjustment Layer, and choose the Levels command. And I'm gonna go ahead and call this layer blacken, just as I did before. Click OK, that's gonna replace curves with levels here inside the Properties panel. And I'll press the Alt key or the Option key on the Mac and drag this black slider triangle until the background goes entirely black, which doesn't really happen at 40 this time around, so I'm gonna take this guy up to 50, like so. And then I'll go ahead and click in the gamma value there and press Shift + Up Arrow a couple of times to take that value up to 1.2, which is gonna brighten my midtones, and I'll go ahead and hide that panel. And so this is our final effect that we're achieving using an arbitrary map. Compare it once again to that effect we achieved using a gradient map. Now if you wanted something along these lines with an arbitrary map, then you would switch back to that file in progress, click in the background, go up to the Image menu, choose Adjustments, and then choose Desaturate. And that way all three of the channels are gonna be identical to each other, and we'd end up with a very similar, however not identical effect. So this is gradient map, and this is arbitrary map. So things are slightly different. But in my mind that kind of defeats the purpose of using an arbitrary map. If I wanted an effect like this, I should just go with a gradient map because it's a lot easier to use. So I'll just go ahead and undo that modification, and I'll press Shift + F in order to switch to the full screen mode, and I will zoom on in as well. And that's at least one way to combine a contour map along with an old school arbitrary map here inside the most powerful image editor on the planet, Adobe Photoshop.

Contents