Adobe photoshop cs2 Manual De Usuario
ADOBE PHOTOSHOP CS2
User Guide
294
Targeting shadows and highlights with Output Levels sliders
To set target values using the eyedroppers
1
Select the Eyedropper tool
in the toolbox. You can choose 3 by 3 Average from the Sample Size menu in the
Eyedropper tool options. This ensures a representative sample of an area rather than the value of a single screen pixel.
2
Open the Levels or Curves dialog box. Choose Image > Adjustments, and then choose Levels or Curves. You can
also use an adjustment layer.
When you open Levels or Curves, the Eyedropper tool
is active outside the dialog box. You still have access to
the scroll controls, the Hand tool, and the Zoom tool
through keyboard shortcuts.
3
Do one of the following to identify areas of highlights and shadows that you want to preserve in the image:
•
Move the pointer around the image, and look at the Info palette to find the lightest and darkest areas that you want
preserved (not clipped to pure black or white). (See “Viewing the color values of pixels” on page 279.)
preserved (not clipped to pure black or white). (See “Viewing the color values of pixels” on page 279.)
•
Drag the pointer in the image, and look at the Curves dialog box to find the lightest and darkest points you want
to preserve. This method does not work if the Curves dialog box is set to the CMYK composite channel.
to preserve. This method does not work if the Curves dialog box is set to the CMYK composite channel.
When identifying the lightest highlight details that you want targeted to a printable (lower) value, don’t include
specular highlights. Specular highlights such as the highlight glint in jewelry or a spot of glare are meant to be the
brightest points in an image. It’s usually desirable to clip specular highlight pixels (pure white, no detail) so that no
ink is printed on the paper.
specular highlights. Specular highlights such as the highlight glint in jewelry or a spot of glare are meant to be the
brightest points in an image. It’s usually desirable to clip specular highlight pixels (pure white, no detail) so that no
ink is printed on the paper.
You can also use the Threshold command to identify representative highlights and shadows before opening Levels or
Curves. (See “To convert images to black and white” on page 313.)
Curves. (See “To convert images to black and white” on page 313.)
4
To assign highlight values to the lightest area of the image, double-click the Set White Point Eyedropper tool
in the Levels or Curves dialog box to display the Color Picker. Enter the values you want to assign to the lightest area
in the image, and click OK. Then click the highlight you identified in step 3.
in the image, and click OK. Then click the highlight you identified in step 3.
If you accidentally click the wrong highlight, hold down Alt (Windows) or Option (Mac OS), and click Reset in the
Levels or Curves dialog box.
Levels or Curves dialog box.
Depending on the output device, you can achieve a good highlight in an average-key image using CMYK values of
5, 3, 3, and 0, respectively, when you are printing on white paper. An approximate RGB equivalent is 244, 244, 244,
and an approximate grayscale equivalent is a 4% dot. You can approximate these target values quickly by entering 96
in the Brightness (B) text box under the HSB area of the Color Picker.
5, 3, 3, and 0, respectively, when you are printing on white paper. An approximate RGB equivalent is 244, 244, 244,
and an approximate grayscale equivalent is a 4% dot. You can approximate these target values quickly by entering 96
in the Brightness (B) text box under the HSB area of the Color Picker.
With a low-key image, you may want to set the highlight to a lower value to avoid too much contrast. Experiment
with Brightness values between 96 and 80.
with Brightness values between 96 and 80.