The Tone System by Roland Miller

Black Point Setting Determination

Black Point/Base Value Evaluation

When you print the targets, make sure you print from a color managed workflow, profiled media/printer combination, and proper print settings. Let your target print dry for 30 minutes before evaluating it. Make sure you are in proper lighting and viewing conditions when you evaluate the target.

When you view the Precision Black Point Target, you should look for two characteristics. One is the first "readily visible" difference between the Specific Test Value (24 in the example below) and the Base Value (0). Readily visible means just that, an obvious difference in value between the two values. To determine this, look at the checkerboard pattern above the center Specific Test Value square where it mixes with the Base Value.

Black Point/Relative Value Evaluation

The second characteristic is the amount of separation between the outer Relative Values (+3 and -3) and the Specific Test Value (again, 24 in the example below). The more separation there is in these values from the the Specific Test Value, the more quickly the shadow tones will show separation and detail when printed. To determine this, look at the checkerboard pattern in the lower right and left hand corners of the sample patch. This is where the Specific Test Value square mixes with the outer Relative Values. You are looking for separation in these values. If you notice a dramatic amount of separation in the Specific Test Value and the inner (+1 and -1) Relative Values, it may indicate a problem with your profile. Be careful with some media surfaces, at an angle, the reflection off different black inks (black vs. light black) may look like tonal separation, but it is not.

Selecting the Black Point Setting from the Base and Relative Value Determinations

Once you have made your visual comparison of these two characteristics, pick a suitable black point setting. You can experiment on actual images to get a feel for how different settings affect actual output.

Black Point and über Black Point

Your decision on where to place the black point setting has some subjectivity. Generally, I believe that a higher number is better. I weigh the black point selection based more on the Relative Value evaluation than the Base Value. This, theoretically, limits your prints from getting the absolute maximum black your printer can produce. Perceptually, it is not noticeable. What this does accomplish is a rapid separation in the shadow tones as they move toward lighter values. This is the major issue most digital printers have with reproducing shadows accurately.

When I must have an absolute black, I use the über Black Point. The über Black Point is determined by evaluating only the Base Value against the Specific Test Value. The über Black Point is typically 5 to 10 values darker than the black point. Remember, by using the über Black Point, you will lose some shadow separation.

To learn about applying these white and black point settings go to the Tone System Color Correction Routine section.

White Point and Black Point Targets  Page 1 • Page 2 • Page 3 • Page 4