Step 4: Increase Tonal Range

We now have located the lightest (#2) and darkest (#3) points in the image and are ready to increase the tonal range. To do so, we use an adjustment layer that lets us change our settings should we need to at a later time, without further degrading the image.

■ To view the entire image, choose View >- Fit on Screen (Ctrl+0). Arrange your combined Color and Info palette to the side so that you can see the values and colors, but still see the entire image.

■ Choose >- Layer >- New Adjustment Layer >-Levels to get the New Layer dialog box. Type Background Levels in the Name box and click OK to get the Levels dialog box shown in Figure 8.11.

■ Click the Set White Point eyedropper, which is the last of the three eyedroppers in the bottom-right corner of the Levels dialog box. Click inside the

8.11

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8.11

small circle next to the #2 marker (the lightest point) in the image to increase the tonal range toward the right side. The image now looks remarkably better.

■ Click the Set Black Point eyedropper, which is the first of the three eyedroppers in the bottom-right corner of the Levels dialog box. Click inside the small circle next to the #3 marker (the darkest point) in the image to increase the tonal range toward the left side. Once again, you should see a significant improvement in the image.

Before applying the settings, click in the Channel box in the Levels dialog box and select each of the channels to see how the end points were adjusted. After these settings are applied, the tonal range is stretched out to include the full tonal range from pure black to white, which increases the contrast — in this image, quite dramatically.

Now look at the R, G, and B values for point #1 in the Info palette. The values for the point I selected now show 254, 252, and 250. These are quite close indicating that the Levels eyedropper tools did a good job of increasing the tonal range, plus it removed the blue color cast. If there were a signifi-

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cant difference in the values for point #1, you would now adjust the appropriate color channels to remove the color cast. The values shown for point #1 are your guide. This process is known as adjusting colors by the numbers.

■ Click OK to apply the Levels adjustment layer. The Layers palette should now look like the one shown in Figure 8.12. If you look in the Info palette, you can now see that the red, green, and blue values are just about equal for all three points, which means that the color cast is now gone.

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