Optimizing the dynamic range of the scan (Photoshop)

Keep in mind that the human eye can detect a wider tonal range than can be printed. If your scanner allows, set the black and white points before scanning a file to produce the best tonal range and capture the widest dynamic range. Then use Photoshop's color adjustment tools to set the white and black points for the scanned image. (See 3. Adjust the tonal range..)