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When levels fail


show more When levels fail provides you with in-depth training on Design. Taught by Deke McClelland as part of the Photoshop CS4 One-on-One: Advanced show less
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When levels fail

Now as we've seen the Levels command is terrific in increasing the contrast of an image, or for modifying midtones, you can boost the midtones to make them lighter, or sink the midtones to make them darker, or adjust shadows, highlights and midtones, independently across the different color channels in order to compensate for color cast. But what about this image right here. The name of this image by the way is High-contrast elephant.jpg, and this is a fairly low resolution image that I shot years and years ago now at the Denver Zoo, for what that's worth. And I ask what about this image, because it doesn't really fit into what I said the Levels command can do. It does have a color cast. It's far too warm. It's too yellowy, too orangey, so we could compensate for that using the Levels command, but we can't do anything about the contrast problems here, because the Levels command is great at increasing contrast, but it's not good at decreasing contrast.

If you want to decrease the contrast of an image, that's one of the scenarios in which you have to graduate from Levels to Curves, as we'll be seeing. So what I'm going to do is in this exercise, I'm going to demonstrate why Levels doesn't work. So that you can anticipate when Levels is going to do you a solid, and when it's going to slip up, and then we will move on to Curves in the next exercise. Now I'm going to approach this color correction, as a static modification. So that is to say I'm going to go up to the image menu, and I'm going to choose Adjustments, and we are going to start by choosing Levels. Now the reason I'm working static is because the Curves command in particular varies quite a bit. The behavior of the Curves dialog box is a little bit different. Actually fairly different than the behavior of the Curves panel here inside the Adjustments palette. So I want to see those differences, and we'll start static, and then move on to a Dynamic adjustment layer. So I'm going to go ahead and choose the Levels command in order to bring up the Levels dialog box here. Now, I suppose I might go ahead and start by increasing the gamma value in order to brighten the body of the elephant, and that does help out this image. But my biggest problem with this image is the shadows and the highlights.

We almost have clipped shadows over here in this left hand area going into the Pachyderm Chamber there, and we almost have clipped highlights against this wall. Not quite, but almost, and there's nothing we can do about that. I can't recover those shadows, and I can't recover those highlights inside the Levels dialog box, because I don't have control over this region right here, or this region right here, what are know as Quarter Tones, by the way, and those are controls that you have inside the Curves. Basically inside the Curves dialog box, you make up your own controls. You put things anywhere where you want them to be, but Levels you just got, shadow, midtones and highlights of course.

So I'm going to go ahead and change that gamma value back to 1, because it's really not doing all that much for us at this point. What I'll do is I'm going to go ahead and press and hold the Alt key, or the Option key on the Mac, and I'm going to click and hold on this black slider triangle right there. And I've still got my Alt or Option key down as I'm just swinging over to this area, so that we can see that this region right here is almost clipped. There's sort of line that is tracing along the elephants head, it is almost a bunch of clipped pixels at this point. We have clipped shadows almost, and I say almost, because generally speaking they are just clipped in one channel or other. But if I were to go any further with this modification, if I was to move it over just ever so slightly here, you can see that we are going to start clipping things very, very quickly.

Our modification is small as moving this black point slider over to 10, it's clipping like crazy inside of the image right there. All right, so obviously we don't want to do that, because we do not want to clip those shadows, and then by contrast we have got the white slider triangle right here. If I was to Alt drag it or Option drag it, I haven't made any modifications so far. You would notice that we have got a line of what appear to be clipped pixels right next to the previously clipped pixels just a moment ago, over along the left side of the elephants head, and if I start moving this slider over, very quickly I start clipping the heck out of that wall in the background.

Now what this proves is two things. First of all it proves that we are not going to do any good for this image. Not any real lasting good with the Levels command. It also proves we're in luck, we have a prayer, because we are not starting off clipped, as we can see here. We have highlight information, and we have shadow information. We just need to bring it out, and we can do that using the Curves command, and we will begin to do that. I'm just going to introduce you to the Curves command in the next exercise, and then we are going to fix this elephant, stick with me.

When levels fail
Video duration: 4m 35s 20h 57m Intermediate

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When levels fail provides you with in-depth training on Design. Taught by Deke McClelland as part of the Photoshop CS4 One-on-One: Advanced

Subjects:
Design Photography
Software:
Photoshop
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