Tone Adjustment
This consists of white and black point adjustments and adjusting of intermediate tones. These can be done using several different tools in Photoshop. We will illustrate using the curve tool in Photoshop, but other tools can be used.
- White point adjustment - Adjust to lightest tone in original. If uncertain scan a gray scale alongside the original so that white point can be set with certainty. This setting is important since it controls the contrast of the reproduction.
- Black point adjustment - Adjust to darkest point in original or to gray scale as appropriate. This along with white point adjustment assures maximum use of tonal range.
- Gradation - Adjust midtones as necessary. In the example we adjusted the RGB levels in curves to achieve both the proper gray balance and intensities.
Color Adjustments - These need to be done to remove color casts and/or adjust gray balance.
- For our sample image we actually removed the color cast by restoring the gray balance. Some adjustments can be made automatically during the scan. Our AGFA scanner can set the white and black points during the preview stage of the scan.
Preparation of Originals - Originals should be cleaned before scanning if possible. In addition the scanner surface(s) should be cleaned before scanning.