Pinpoint Proper Contrast with Photoshop Elements 10 Levels
If you want real horsepower when it comes to correcting the brightness and contrast (and even the color) in your image, look no further than the Levels command. Granted, the dialog box is a tad more complex than what you find with the other lighting and color adjustment commands, but when you understand how it works, it can be downright user-friendly.
You can get a taste of what Levels can do by using Auto Levels. The Levels command, its manual cousin, offers much more control. And unlike the primitive Brightness/Contrast control, Levels enables you to darken or lighten 256 different tones. Keep in mind that Levels can be used on your entire image, a single layer, or a selected area. You can also apply the Levels command by using an adjustment layer.
If you’re serious about image editing, the Levels command is one tool you want to know how to use. Here’s how it works:
In Full Photo Edit or Quick Photo Edit mode, choose Enhance→Adjust Lighting→Levels.
Use Full Photo Edit mode for this command, where you’ll have access to the Info panel in Step 2.
The Levels dialog box appears, displaying a histogram. This graph displays how the pixels of the image are distributed at each of the 256 available brightness levels. Shadows are shown on the left side of the histogram, midtones are in the middle, and highlights are on the right.
Note that, in addition to viewing the histogram of the composite RGB channel (the entire image), you can view the histogram of just the Red, Green, or Blue channel by selecting one of them from the Channel panel menu.
Although you generally make changes to the entire document by using the RGB channel, you can apply changes to any one of an image’s component color channels by selecting the specific channel from the Channel panel menu. You can also make adjustments to just selected areas, which can be helpful when one area of your image needs adjusting and others don’t.
In Full Photo Edit mode, choose Window→Info to open the Info panel.
Set the black and white points manually by using the eyedroppers in the dialog box; first select the White Eyedropper tool and then move the cursor over the image.
Look at the Info panel, try to find the lightest white in the image, and then select that point by clicking it.
The lightest white has the highest RGB values.
Repeat Steps 3 and 4, using the Black Eyedropper tool and trying to find the darkest black in the image.
The darkest black has the lowest RGB values.
When you set the pure black and pure white points, the remaining pixels are redistributed between those two points.
You can also reset the white and black points by moving the position of the white and black triangles on the input sliders (just below the histogram). Or you can enter values in the Input Levels boxes. The three boxes represent the black, gray, and white triangles, respectively. Use the numbers 0 to 255 in the white and black boxes.
Use the Gray Eyedropper tool to remove any colorcasts by selecting a neutral gray portion of your image, one in which the Info panel shows equal values of red, green, and blue.
If your image is grayscale, you can’t use the Gray Eyedropper tool.
If you’re not sure where there’s a neutral gray, you can also remove a colorcast by choosing a color channel from the Channel pop-up menu and doing one of the following:
Choose the Red channel and drag the midtone slider to the right to add cyan or to the left to add red.
Choose the Green channel and drag the midtone slider to the right to add magenta or to the left to add green.
Choose the Blue channel and drag the midtone slider to the right to add yellow or to the left to add blue.
If your image requires it, adjust the output sliders at the bottom of the Levels dialog box.
Moving the black triangle to the right reduces the contrast in the shadows and lightens the image. Moving the white triangle to the left reduces the contrast in the highlights and darkens the image.
Adjust the midtones (or gamma values) with the gray triangle input slider.
The default value for gamma is 1.0. Drag the triangle to the left to lighten midtones and drag to the right to darken them. You can also enter a value.
Click OK to apply your settings and close the dialog box.
Your image should be greatly improved.
When you click the Auto button, Elements applies the same adjustments as the Auto Levels command. Note the changes and subsequent pixel redistribution made to the histogram after you click this button.