Highest Quality Capture: Workflow Phase I - Black and White in Photoshop CS4 and Photoshop Lightroom - page 53

Example 6. Low Key Images Exposed with Highlight Preference
The image below of Agenina Nakanyike, a Ugandan bean farmer and mother
of four, is an excellent example of a low key image, whereby almost all of
the data in the image falls within the darkest values of the data chart. The
image maintains a small amount of information towards the highlight values
preserving the light and detail on the woman's face. The corresponding
histogram for both exposures indicates major loss in shadow information,
as illustrated by the slam of data to the left side of the histogram indicating
much information falls to black. As no image detail extends beyond the right
side of the scale, the exposure captures all the important details contained in
highlight information in this scene.