Join Deke McClelland for an in-depth discussion in this video Correcting an image in Lab, part of Photoshop CS4 One-on-One: Advanced.
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Now, the images that we've seen so far have been in astoundingly wretched shape, quite frankly, and that's because I want you to have a sense for just how miraculous Photoshop is where Levels and Curves are concerned. Just how they can produce those absolutely astounding modifications. But it stands to reason if it can fix images that are in terrible shape, why then it can fix your images that are in moderately good shape even better. It is very much to be hoped that your images will be in better shape. More along the lines of the image that we're seeing right here on screen. It's called Max snorkels.jpg.
Now, it still does need some work, because I shot this image underwater with an Olympus Stylus 1030 SW actually; a nice little point and shoot camera that can go 33 feet deep, 10 meters deep, it's awesome. The thing is of course, once you start shooting underwater, you typically lose your yellows and your reds very, very quickly, and then you start losing other colors as you go farther down. So this requires some correction of course. Now, what I'm going to tell you is that, when I'm correcting images, I tend to work in one of two ways. Either I'll take my Raw images, that were shot in the Camera's Raw file format, and I'll process them inside of Camera Raw; and we will learn about Camera Raw, which is this terrifically powerful sort of subprogram of Photoshop, we'll learn about it in a future chapter.
If I'm working from JPEGs however, and this particular camera, the Stylus 1030, doesn't allow you to capture raw images, so if I'm working with JPEG, I might take them in to Camera Raw. You can do that as we will see later. Or I might take them into the Lab Color mode. What I'm going to do is I'm going to show you basically how Lab works, how to apply a quick and dirty correction, and then I'm going to send you on your way. If you're interested in Lab, I've got a six hour series devoted to the topic. Its sort of a separate discipline essentially is what it comes down to, and we spend a ton of time in that series on Levels and Curves inside the Lab Color mode.
But here goes. So I'm working with Max snorkels.jpg, and it's an RGB image. You can see that in the title tab right there, RGB/8, meaning it's 8 bits of data per channel. All right. So I'm going to go ahead and go over here to the Adjustments palette, Alt+Click on the little Levels guy right there, and I'll call this RGB levels, and then I'll click OK. All I'm going to do is I'm just going to go ahead and Alt+Click or Option+Click on that Auto button right there, in order to bring up the Auto Color Correction Options dialog box. I'm going to switch to Find Dark & Light Colors, which as you may recall is the Auto Color function.
I'm not going to Snap my Neutral Midtones, because notice, this is what happens if you Snap Neutral Midtones for this image, we end up losing a lot of the nice bright happy pinks, and I want those bright happy pinks back. So I'm going to turn that checkbox off right there, and I'll click OK in order to accept that modification. I have to say that is pretty darn good for three seconds of work. I have no complains really. The thing is it could be better. It could be better if I started probably tweaking the settings here inside of my Adjustments palette on a Channel by Channel basis. But it could even be better still if we apply a quick and dirty, not much more complicated correction inside the Lab Color mode, because Lab just so happens to be more powerful and more magical.
So here is what we are going to do. I'm going to grab this Background layer right there, and I'm going to drag it on to this little page icon down here, at the bottom of the Layers palette, and I'm going to press and hold, before I release, I'm going to press and hold the Alt key or the Option key on the Mac, and then I'll release. What that does is that forces the display of the Duplicate Layer dialog box and then you change document from Max snorkels to New right there. So that you're putting this layer into a new document, and then you just click OK, and notice you now have a new document, that's called, in my case Untitled 3, its probably Untitled 1 or something like that for you.
But anyway, you should see this Background layer inside the Layers palette. Then go up to the Image menu, choose mode, and choose Lab Color. Now, I go into detail in my alternative series, that is not this series, but it's called Photoshop CS3 by the way, Mastering Lab Color. It's part of the lynda.com Online Training Library. I may end up updating it for CS4 later in 2009, not really sure exactly what order we're going to do things at this point. But I'm here to tell you, even if you're working in Photoshop CS4, it's totally accurate, so you will be able to follow along, no problem.
So anyway, we'll go to Lab Color, and the reason I'm mentioning this is because I define in very specific terms what the Lab Color mode is and how it compares to RGB and CMYK and so on. Anyway, let's go to Lab. That just goes ahead and converts it to this device independent wonderful amazing color model here. This time we have three Channels; I'll go ahead and switch to the Channels palette for just a moment here, which is the actual luminance information for the image. Then we have a and then we have b, and they don't look like much, but they're really great.
a is the Tint information for the image. Meaning that, if I go ahead and turn on Lightness and a, you'll see what I'm talking about. We've got the greens and the pinks essentially inside of the image. It's more like turquoise to pink is really what we've got going. People say that it's the greens to magentas, but that's not quite right. Then I'll turn off a for a moment and turn on b. This is the Temperature information, and it varies from yellow to blue. Then when you put them all together, why then, you've got yourself a full color image. All right. So how in the world do you work with that wackiness? Well, let's go back to Lab. Make sure that the Lab Composite image is selected there in the Channels palette. Return to Layers. I'm going to once again Alt+Click or Option+Click on this little Levels icon; I'm going to call this one Lab levels, but of course. Click OK.
Now check this out. I'm going to go ahead and click on the Auto button in order to correct just the Lightness Channels. It's not going to do anything to the a or b Channels. It's just changing the luminance information. So our colors look a little sort of weak at this point, but we have some sizzling contrast going on, thanks to Auto. Now, you may wonder what variety of Auto is that, Deke? Let's go ahead and Alt+Click or Option+Click on the Auto button to see our Auto Color Correction Options, and we'll see, it's not any of the varieties, it's actually all the varieties. It's actually just plain Auto Contrast, because Auto Tone and Auto Color, they require three channels of information to get any work done. So it's just applying Auto Contrast to this guy, and that's your only option. So don't worry about it, just click Cancel out of there.
Then let's go over to the a Channel. Tell you what I recommend you do. What you want to do is you just want to symmetrically increase the contrast of your a and b Channels which will increase the Saturation of the colors inside the image and bring them up to speed with the luminance modifications right here. So notice this tiny little histogram right there, that's very typical for the a and b Channels. Don't fret. Just do this. Click inside this first value right there. I'm going to press Shift+Up Arrow six times in a row until we get a value of 60, and then I'm going to Tab, Tab, ignore the gamma value, come over to the white point value and press Shift+Down Arrow six times in a row. I forgot to count that, so I better count it.
The reason I'm pressing Shift+Down Arrow x number of times in a row as opposed to entering values is it's just easier. That way I know that I'm getting a symmetrical modification, so I don't have to do-- Not very complicated math to do 255-60=195, but still, you don't have to do it. Just press Shift+Down Arrow as many times as you press Shift+Up Arrow for this guy. Then switch over to b, and notice, we've still got the same keyboard shortcuts. So we've got Alt+3 or Option+3 on the Mac for the first channel. Alt+4, Option+4 on the Mac for the second channel. Alt+5, Option+5 on the Mac for the third channel. Notice there is no composite. You cannot modify the composite image in Lab, where Levels is concerned.
All right. Let's switch to b, do the exact same thing. Shift+Up Arrow six times. Six is not a magical number, it just happens to work nicely for this image. However, whatever number you come up with, like if you press Shift+Up Arrow four times in a row, and then Shift+Down Arrow four times in a row, just make sure you do the same thing for the a and b Channels to start with. So then I'm going to press Shift+Down Arrow six times in a row for the white point, here inside the b Channel. When I'm manipulating the black point, notice that I'm adding or I'm actually doing; let's go ahead and take this out, I'm going ahead and adding blue as I'm taking this value up. So as I'm making this channel darker, I'm adding blue, and when I make that channel lighter, I'm offsetting the blue by adding yellow.
What's happening with the a channel here is the black point is the turquoise and the white point is the pink, just FYI. Then I'm coming back to the a Channel here. The reason this becomes important is because Max's snorkels goggles here, I know that they're actually yellow, and these are more of a sort of screaming chartreuse at this point. That's not what I want. So I'm going to black off the green. So black is green, white is pink, and in b, black is blue and white is yellow. If you can remember that, that's good.
All right. I'll go to a, and I'll say let's back off the green/turquoise, whatever, press Shift+Down Arrow and that pretty much takes care of it. And we are done. That's it, folks. Now, it's a little strange, it's a little peculiar. You sort of have to wrap your brain around the different color space, but if you can come to terms with it, and believe me, my Mastering Lab Color series, it's just six hours long, its not hard, its just different, that's all. Sometimes different is good; in this case it really is good. Anyway, here is the RGB correction. So not bad, but a little low on the Saturation values, as you can see. Whereas, my Lab version of the image has some really sizzling Saturation, some great skin tones, and is quite accurate to the scene that I actually shot. So again, just for those of you who are interested, Photoshop CS3 Mastering Lab Color right here on the lynda.com Online Training Library.
In the next exercise, we are going to switch to our last topic for this chapter, which is Shadows Highlights; just little bit of information on Shadows Highlights, and I'll then send you on your way to the next chapter.
Recommended prerequisite: Photoshop CS4 One-on-One: Fundamentals.
Download Deke's customized keyboard layouts and color settings for Photoshop under the download feature.
- Using blend modes, adjustment layers, and layer styles
- Organizing a layered composition so it is fluid and editable
- Creating and editing type in Photoshop
- Using blur effectively
- Using adjustment layers to add color
- Combining layers into a clipping mask
- Working with Camera Raw