Assigning values to the and white points

blackYou can further improve the quality of the image by adjusting the black and white limits of its tonal range. In Lesson 3, “Basic Photo Corrections,” you learned to use the sliders on the Levels command histogram to adjust the range. In this lesson, you’ll control the range more accurately by using the Levels command eyedropper to assign specific values to the darkest and lightest points.

1.	Choose Image > Adjustments > Levels.
2.	In the Levels dialog box, double-click the white eyedropper tool () to open the color picker for the white point.
3.	Enter 0, 0, 0, and 5 in the CMYK text boxes, and click OK. These values generally produce the best results when printing the white points (highlights) of a grayscale image onto white paper.
4.	Next double-click the black eyedropper tool () in the Levels dialog box to open the color picker for the black point.
5.	Enter 0, 0, 0, and 95 in the CMYK text boxes, and click OK. These values generally produce the best results when printing the black points (shadows) of a grayscale image onto white paper. Now that you’ve defined the values for the black and white points, you’ll use the Levels command eyedropper to assign the values to the darkest and lightest areas in the image.
6.	Make sure that the black eyedropper tool is selected, and position it in the darkest area of the framework behind the woman’s elbow. Click to assign this area the values you set in step 5.
7.	Next, select the white eyedropper tool in the Levels dialog box, position the tool in the lightest area of the woman’s collar, and click to assign this area the values you set in step 3. Black eyedropper selecting darkest area behind elbow White eyedropper selecting lightest area in collar
8.	Click OK to close the dialog box and apply the changes. If an alert message appears, click No so that the new target colors do not become the defaults. Assigning the black and white points shifts the image’s histogram to produce a more evenly distributed tonal range. Original Result
9.	Choose File > Save.