Adobe PHOTOSHOP 5.0, User Manual, Page: 103 / 400

95 ADOBE PHOTOSHOP 5.0
User Guide
•
Click to add an adjustment point in the dot gain
curve, and drag the point to change its value. The
value then appears in the appropriate text box.
•
Click OK.
Applying dot gain settings to grayscale
images
If your grayscale images will be viewed only on-
screen, you don’t need to compensate for dot gain.
However, if you will print your images, you should
apply the same dot gain values you used for CMYK
output.
To specify Grayscale Setup settings:
1
Choose File > Color Settings > Grayscale Setup.
2
Select Preview to display a preview of your
changes.
3
Select a grayscale behavior option:
•
RGB to work without any compensation for
dot gain.
•
Black Ink to use the dot gain settings specified in
the CMYK Setup dialog box. This option is equiv-
alent to choosing the Use Dot Gain for Grayscale
Images option in Photoshop 4.0.
4
Click OK.
Compensating for dot gain in film using
transfer functions
When using ICC profiles, you cannot adjust the
dot gain with the CMYK Setup dialog box.
However, you may be able to compensate for dot
gain from a miscalibrated imagesetter by using the
transfer functions.
Transfer functions enable you to compensate for
dot gain between the image and film. For example,
the Transfer function makes 50% dots in the image
print as 50% dots on film. Similarly to dot gain
curves, the transfer functions let you specify up to
13 values along the grayscale to create a
customized transfer function.
The following guidelines can help you in using
transfer functions:
•
Check that the printer is not miscalibrated. (See
“Calibrating the screen image to the proof ” on
page 92.)
•
Do not use transfer functions to compensate for
dot gain from film to press. Instead, use the dot
gain curves in the CMYK Setup dialog box. (Dot
gain curves affect the CMYK to RGB conversions
and on-screen display, but transfer functions apply
only to printing—they don’t affect the image color
data. (See “Specifying dot gain” on page 94.)
Important: Remember, use the transfer functions
only for dot gain problems that cannot be fixed any
other way.
To adjust the transfer function values:
1
Use a transmissive densitometer to record the
density values at the appropriate steps in your
image on film.
2
Choose File > Page Setup.
3
Click the Transfer button.