How to use it
The three most left vertical bands (black) and the three most right bands (white) must be distinguishable. For best results, the length of the chart must be set in pixels to the ¾ total width of the screen. For example, if you have a 1024x768 screen, the grey chart's size should be ±760 pixels length. If you cannot set a correct contrast (correct means that you can see ALL the bands), you will not be able to make a correct retouching job: you will not see all the shades in the image.
