People who’ve used Elements for a while will tell you that the Levels command is one of the program’s most essential tools. You can fix an amazing array of problems simply by adjusting the level of each color channel. (On your monitor, each color you see is composed of three channels: red, green, and blue. In Elements, you can make very precise adjustments to your images by adjusting these channels separately.)
Just as its name suggests, Levels adjusts the amount, or level, of each color in an image. You can make several different adjustments with Levels, from generally brightening your colors to fixing a color cast (Removing Unwanted Color has more about color casts). Many digital photo enthusiasts treat almost every picture they take to a dose of Levels because there’s no better way to polish up the color in a photo.
The way Levels works is fairly complex. Start by thinking of the possible ranges of brightness in any photo on a scale from 0 (black) to 255 (white). Some photos may have pixels in them that fall at both those extremes, but most photos don’t. Even the ones that do may not have the full range of brightness in each individual color channel. Most of the time, you’ll find some empty space at one or both ends of the scale.
When you use Levels, you tell Elements to consider the range of colors available in your photo as the total tonal range it has to work with, and Elements redistributes your colors accordingly. Basically, you just get rid of the empty space at the ends of the scale of possibilities. This can dramatically change the color distribution in your photo, as you can see in Figure 7-9.
Fortunately, it’s much, much easier to use Levels than to understand it, as you know if you’ve tried Auto Levels in Quick Fix (Adjusting Lighting and Contrast). That command is great for, well, quick fixes. But if you really need to massage your image, Levels has a lot more under the hood than you can access in Quick Fix. The next section shows you how to get at these settings.
Figure 7-9. A simple Levels adjustment can make a huge difference in the way your photos look. Left: The gray-green cast to this photo makes everything look dull. Right: Levels not only gets rid of the color cast, but also helps give the photo better contrast and sharpness.
Before you get started adjusting Levels, you need to understand the heart, soul, and brain of the Levels dialog box: the Histogram, shown in Figure 7-10. (You can call up this dialog box by pressing Ctrl+L/⌘-L.)
Figure 7-10. One of the scariest sights in Elements, the Levels dialog box is actually your friend. If it frightens you, take comfort in knowing that you can always click the Auto button here, which is the same Auto Levels command as in Quick Fix. But it’s worth persevering: The other options here give you much better control over the end results.
The Histogram is the black bumpy mound in the middle of the dialog box. It’s really nothing more than a bar graph indicating the distribution of the colors in your photo—there’s just no space between the bars, which is why it looks like mountains.
From left to right, the Histogram shows the brightness range from dark to light (the 0 to 255 mentioned earlier in this section). The height of the “mountain” at any given point shows how many pixels in your photo have that particular brightness. You can tell a lot about your photo by where the mound is before you adjust it, as explained in Figure 7-11.
Above the Histogram is a Channel menu that says “RGB.” If you click it, you can choose to see a separate Histogram for each individual color. You can adjust all three channels at once with the RGB setting, or change each channel separately for maximum control.
Figure 7-11. Top: If the bars in your Histogram are all smooshed together like this, your photo doesn’t have a lot of tonal range. As long as you like how the photo looks, that’s not important. But if you’re unhappy with the photo’s color, it’s usually harder to get it exactly right in this kind of photo than in one that has a wider tonal range. Middle: If the mound is bunched up on the left side, your photo is underexposed. Bottom: If you just have a big lump on the right side, your photo is overexposed.
The Histogram contains so much info about your photo that Adobe also makes it available in the Full Editor in its own panel (Figure 7-12), so you can always see it and use it to monitor how you’re changing the colors in an image. Once you get fluent in reading Histogramese, you’ll probably want to keep this panel around.
The Histogram is just a graph, and you don’t do anything to it directly. When you use Levels, you use the Histogram as a guide so that you can tell Elements what to consider the black and white points—that is, the darkest and lightest points—in your photo. (Remember, you’re thinking in terms of brightness values, not shades of color, for these settings.)
Figure 7-12. If you keep the Histogram on your desktop, you can always see what effect your changes are having on the photo’s color distribution. To get this nifty Technicolor view, go to Window→Histogram and then choose Colors from the panel’s drop-down menu. To update the Histogram, click the triangle in its upper right as shown here. If you’re really into statistics, there are a bunch of them at the bottom of this panel, but if you’re not a pro, you can safely ignore these numbers.
Once you’ve set these end points (you’ll learn how in a moment), you can adjust the midtones—the tones in between that would appear gray in a black-and-white photo. If that seems complicated, it’s not—at least, not when you’re actually doing it. Once you’ve made a Levels adjustment, the next time you open the Levels dialog box, you’ll see that your Histogram now runs the whole length of the scale because you’ve told Elements to redistribute your colors so that they cover the full dark-to-light range.
The next two sections show you—finally!—how to actually adjust your image’s Levels.
Tip
Once you learn how to interpret the histograms in Elements, you can try your hand with your camera’s histogram (if it has one). It’s really hard to judge how well your picture turned out when all you have to go by is your camera’s tiny LCD screen, so your camera’s histogram can be a big help in figuring out how well exposed your shot was.
One way to adjust Levels is to set the image’s black, white, and/or gray points by using the eyedroppers in the Levels Adjustments panel. It’s quite simple—just follow these steps:
Bring up the Levels Adjustments panel by selecting Layer→New Adjustment Layer→Levels.
If you like, you can name the layer in the New Layer dialog box that appears, or just click OK to get on with it and create your layer. If you don’t want a separate layer for your Levels adjustment, go to Enhance→Adjust Lighting→Levels or press Ctrl+L/⌘-L instead. (You’ll get a dialog box instead of the panel, but it works exactly the same way.) But making the Levels changes on an Adjustment layer gives you more flexibility for making future changes.
If necessary, move the Adjustments panel or the Levels dialog box out of the way so you have a good view of your photo.
The dialog box loves to plunk itself down smack in the middle of the most important part of your image. Just grab it by the top bar and drag it somewhere else.
In the Adjustments panel or Levels dialog box, click the black eyedropper.
In the Adjustments panel, from top to bottom, the eyedroppers are black, gray, and white. In the dialog box they’re arranged from left to right instead.
Move your cursor over your photo and click an area that should be black.
Should be, not is. That’s a mistake lots of people make the first time they use the Levels eyedroppers: They click a spot that’s the same color as the eyedropper rather than one that ought to be that color. For instance, if your photo includes a wood carving that looks black but you know it should be dark brown, that’s a bad place to click. Try clicking a black coffee mug or belt, instead. This is called “setting a black point.”
Repeat with the other eyedroppers for their respective colors.
Now find a spot that should be white (like maybe a cloud that’s a little off-white now) and one that should be gray to set your white and gray points. That’s the way it’s supposed to work, but you can’t always use all the eyedroppers in a given photo. Experiment to see what gives you the best-looking results.
If you’re using the dialog box, when you’re happy with what you see, click OK.
If you’re working with the Adjustments panel, you don’t have to do anything: Elements has already applied your changes, so you’re done.
See, it’s not so hard. If you mess up, just click the dialog box’s Reset button to start over again. (In the Adjustments panel, click the square made of four horizontal lines at the panel’s upper right, and then choose Reset Levels from the drop-down menu.)
The eyedropper method works fine if your photo has spots that should be black, white, or gray, but sometimes your pictures won’t have any of these colors. Fortunately, the Levels sliders give you yet another way to apply Levels, and it’s by far the most popular method, giving you maximum control over your colors.
Right below the Histogram are three little triangles called Input sliders. The left slider sets the black point in your photo, the right slider sets the white point, and the middle slider adjusts the midtones (gray). You just drag them to make changes to the color levels in your photo, as shown in Figure 7-13.
Figure 7-13. To use the Levels Input sliders, simply drag the left and right sliders from the ends of the track until they’re under the outer edges of the color data in the graph. The red arrows in this figure show where you’d position the left and right sliders for this particular photo. If there’s empty space on the end of the graph, just move the slider until it’s under the first mound of data.
When you move the left Input slider, you tell Levels, “Take all the pixels from this point down and consider them black.” With the right slider, you’re saying, “Make this pixel and all higher values white.” The middle slider adjusts the brightness values that are considered medium gray. All three adjustments improve the contrast of your image.
Tip
If there are small amounts of color data (flat lines) at the ends of the Histogram, or if all the data is clumped in the middle of the graph—watch your photo as you move the left and right sliders to decide how far in you should bring them. Moving them all the way in may be too drastic. Your own taste should always be the deciding factor when you’re adjusting a photo.
The easiest way to use the Levels sliders is to:
Bring up the Levels dialog box or the Levels Adjustments panel.
Use one of the methods described in step 1 of the eyedropper method (Adjusting Levels: The Eyedropper Method). If necessary, move the dialog box or Adjustments panel so you’ve got a clear view of your photo.
That’s the one below the left end of the Histogram.
Slide it to the right, if necessary.
Move it over until it’s under the farthest left part of the Histogram that has a mound in it. If you glance back at Figure 7-13, you’d move the left slider just a tiny bit, to where the left red arrow is. (Incidentally, although you’re adjusting your image’s colors, the Levels Histogram is always black and white no matter what you do—you don’t see any color in the dialog box itself.)
You may not need to move the slider at all if there’s already a good bit of data at the left end of the Histogram. It’s not mandatory to adjust all the sliders for every photo.
Grab the white slider (the one on the right side) and move it left if necessary.
Bring it under the farthest right area of the Histogram that has a mound in it.
Now adjust the gray slider.
This is the midtones slider, and it adjusts the midtones of your image. Move it back and forth while watching your photo until you like what you see. This slider has the most impact on the overall result, so take some time to play with it.
If you’re using the dialog box, click OK.
You can adjust your whole image at once or each color channel individually. The most accurate way is to open the Levels dialog box and to choose each color channel separately from the Channel drop-down menu. Adjust the end points for each channel, and then choose RGB from the menu and tweak just the midtones (gray) slider.
Tip
If you know the numerical value of the pixels you want to designate for any of these settings, you can type that information into the unlabeled Input Levels boxes below the Histogram. You can set the gray value from .10 to 9.99 (it’s set at 1.00 automatically), and the other two boxes anywhere from 0 to 255.
The last control you may want to use in the Levels dialog box or Levels Adjustments panel is the Output Levels slider, which works roughly the same way as the brightness and contrast controls on your TV. Moving this slider makes the darkest pixels darker and the lightest pixels lighter. Image pros call this “adjusting the tonal range of a photo.”
Adjusting Levels can improve almost every photo you take, but if your image has a bad color cast—if it’s too orange or too blue, say—you may need something else. The next section explains how to get rid of color like that.