Brightness button without releasing it invokes the Brightness slider, as shown in Figure
13.5a, which allows you to drag a white slider control to select the brightness value.
Figure 13.5a The Brightness slider control in the Scan dialog – Macintosh.
Windows: The Brightness button in the Scan dialog, the circle with the small
lines radiating from it, enables you to set the brightness value through the associated
Brightness value edit box. The Brightness value edit box can be changed by clicking in
the box and entering the new value. The Brightness value can range from 25 to 100 for
Coolscan, and 0 to 255 for LS-3510AF.
Figure 13.5b The Brightness value edit box in the Scan dialog – Windows.
Contrast
The Nikon Scanner plug-in’s contrast controls allow you to adjust the overall
contrast of a scan. Decreasing the contrast is equivalent to darkening the highlights
(lightest areas) at the same time as the shadows (darkest areas) are lightened. Increasing
the contrast is equivalent to lightening the highlights while darkening the shadows.
Using the correct contrast setting when scanning is critical to achieving good
results. This is because the dynamic range of film is greater than the dynamic range of
the scanner. That is, the film contains a wider range of densities than is reproducable by
the imaging system. This is the case for any digital imaging system.
It should be noted that the contrast control is a global tone control, meaning it
will effect the entire scan, not just certain densities. Accurate local tone control, affect-
ing only highlights, midtones, or shadows, can be achieved by modifying the gamma
curves. Modifying the gamma curves is discussed in Chapters Twelve and Thirteen.
For example, suppose that the darkest subject in a photo is not very dark.
Further, the lightest subject in the photo is not very bright. All of the information in
this photo therefore resides in the midtones (the tonal values located approximately
halfway between the highlights and shadows). One way to increase the readability of
the image is to increase the contrast by darkening the shadows and lightening the high-
lights.
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Software Reference for Scanners
Contrast, Brightness and Color Balance
Chapter 13
Содержание Scanners
Страница 1: ...Software Reference for Scanners ...
Страница 14: ...Page XIV Software Reference for Scanners Table of Contents ...
Страница 36: ...Page 22 Software Reference for Scanners Software Installation IBM PC or Compatible Chapter 3 ...
Страница 92: ...Page 78 Software Reference for Scanners Setting and Restoring the Nikon Plug in State Macintosh Chapter 8 ...
Страница 126: ...Page 112 Software Reference for Scanners Cropping and Sizing Images Chapter 11 ...
Страница 132: ...Page 118 Software Reference for Scanners Film Type and Orientation Chapter 12 ...
Страница 146: ...Page 132 Software Reference for Scanners Focusing with Coolscan Chapter 14 ...
Страница 170: ...Page 156 Software Reference for Scanners The Gamma Curve Editor Dialog Chapter 16 ...
Страница 194: ...Page 180 Software Reference for Scanners Troubleshooting Windows ...