248 THE EXTREMES
e darkest pixels are on the histogram’s le side. e lightest are on the
right, and the middle-gray tones are in the middle. When we put all this
pixel information together, we end up with a graph that shows us what tonal
values are present in a picture and how they are distributed throughout it.
To translate this into the language of grayscale values, we can say that
the blackest of blacks at the histogram’s far le has a tonal value of 0. e
whitest of whites has a tonal value of 255, and the middle gray has a tonal
value of 128. For those familiar with the Zone system, the far le of a histo-
gram corresponds to the “0” Zone. e middle gray corresponds to Zone V,
and the far right corresponds to Zone X.
Earlier we told ...