Study of Head of Man

This is a great example of a very competent charcoal portrait drawing. It also goes to show why charcoal is a great medium for this purpose, and that is primarily because of the range of value you can achieve. This drawing has a real sense of gravitas and I believe this comes from the strong lights, rich darks, and the way half of the face is basically in shadow. Look at how strong the darks are in the man's hair, eyes, moustache, and soul patch. The artist also captured a strong light on the subject's forehead and his white shirt. The nice thing about charcoal is that even within the shadow, one can modulate the tone to depict reflected light (in the subject's right cheek and neck.)

There is another reason why charcoal drawings like this attain this kind of heavy mood and feeling. This is a bit of a subtle point, so bear with me. Take a look at the man's deep-set eyes and how his eyelids catch just a bit of light. Squint your eyes, for a moment, and look at the image of this drawing. With your eyes squinted, you should just see pools of dark around the eyes with small stabs of light on the eyes. If this were a photograph, I suspect most cameras would catch the light coming from the recesses of the man's eye socket, which means the eye sockets would not be such pools of dark. To achieve the same effect with a camera would require creating a very high level of contrast. It would require a really strong light or light-source or some heaving editing after the fact, and either way, it probably would not look as natural. 

The point is that the moody look and feel of this drawing is a unique thing to this medium and hard to replicate.