Photoshop CS Timesaving Techniques For Dummies [Electronic resources] نسخه متنی

Setting Levels to Adjust Tone and Color

Levels are used to correct the tone and color balance in an image by adjusting shadows, midtones, and highlights. You can apply levels to an entire image, an entire layer, or a selected area on a layer.

You can also apply a level as an adjustment layer. Open an image and choose Image>Adjustments> Levels or press Ctrl/z +L to view the Levels dialog box, shown in Figure 30-2. (To apply levels as an adjustment layer, click the Create New Fill or Adjustment Layer button at the bottom of the Layers palette and choose Levels from the menu. The dialog box shown in Figure 30-2 appears on-screen.)

Figure 30-2: Use the sliders in the Levels dialog box to adjust highlights, midtones, and shadows.

Notice how the Levels dialog box is set up. At the top is a Channel drop-down list that lets you select an individual channel or the composite channel for correction. Below that is the histogram, which shows a graphical representation of how the lights and darks in the image are distributed. When you adjust levels, you use the Histogram palette as a guide. Take a look at the sidebar “How do you read a histogram?” for details on how the histogram works.

Directly below the histogram are the really important sliders in this dialog box: Input Shadow, Midtone, and Highlight. Here’s how they work:

Move the Shadow slider to the right to increase the dark tones in the image, making all the pixels darker. As the Shadow slider moves right, so does the Midtone slider.

Slide the Midtone slider to the left to make the midtones lighter. Move the slider to the right to make the midtones darker.

Move the Highlight slider to the left to increase the highlights, making all the pixels lighter. As the Highlight slider moves left, so does the Midtone slider.

Below the input sliders are the output Shadows and Highlights sliders at the bottom of the Levels dialog box. Use these sliders (very judiciously) when you finish color correcting the image and just want to heighten the overall intensity of the shadows and highlights.

Take a look at Color Plate 30-1 to see the amazing changes levels can make.