The black lighting technique is when source of light in a photograph is behind the subject, usually creating a dark silhouette of the subject.
This effect can also be achieved when editing a photograph in a software such as Photoshop.
Some examples of black lighting:
My Images
These images are similar to the work of Keld Helmer-Petersen because of the strong contrast between the highlights and the shadows, only using black and white. This creates a silhouette effect.