Phase One H 5 manual Levels, Curves, 13.10 13.11

Editing and Selecting Images

To control the brightness and contrast of the image two standard tools are available: Levels and Curves.

Levels

The first part of the Exposure Tab is the Levels control. This is a standard levels box similar to that of Adobe Photoshop. To make an adjustment drag the black or white slider left or right to either darken the shadows or lighten the highlight. Alternativly, click on the black or white eyedropper and select an area of the image to set as the shadow or highlight point. Beneath the display are preview windows showing the “before and after” of the changes.

At the top of the window settings and tonal adjustments can be loaded, or saved for future use. The “Preserve Balance” option ensures that all three color channels are adjusted simultaneously. If this option is un-checked the three color channels can be con- trolled independently.

Editing and Selecting Images

Curves

The next window in the Exposure tab is the Curves control, again this is a standard Curves control that may look familiar to those of other imaging programs.

The Curves control is extremely powerful and can be used to control every tone in the image. An imaging curve is a graph that represents the original data along the bottom and the output or developed data along the side. The dark tones are to the left, while the light colors are on the right. The default curve is a straight line, which means that the

image data is not changed by the curve. To use the curves, click anywhere along the line to add a point and then drag the point up or down to affect the tone in the image.

In the example a point has been added in the lower (darker) end of the curve (called the three-quarter tone) and pulled down. This will make that point darker in the developed image. A second point was added in the quarter-tone (light end of the curve) and pushed up. This will make that point lighter. In addition to darkening and lightening these two selected points, because the entire curve was shifted between these points an overall increase in contrast will occur from this “minor” change.

Curves are extremely powerful and should be used with caution and discretion. Again, as with the Levels control, RGB channels can be controlled individually, and settings saved and loaded.

13.10 13.11