Light and shadow are an important part of art. Yes, there are some styles where this is ignored. For example, Chinese ink painting has no room for light and shadow, focusing more on subtle variations of the color black. Japanese woodblock prints favor contrasts of color over the depth shadow gives.
However, the interplay of light and shadow, on what is hidden or exposed by the balance of the two is of great importance to one particular style. This visual style is known as chiaroscuro and is most often associated with film noir.
Chiaroscuro first emerged back in the Renaissance. It came about due to the bold use of dark and light contrasts, affecting the “emotion” of an entire composition or work.
A dark room with lights cutting a character down the middle, light flowing through partly-opened blinds, is a common element of the style. It makes things more distinctive visually, despite being low-key. The contrast also helps mask background details that you don’t want to be made visible.
Achieving this effect in your studio is also relatively straightforward. You first need to wash the space in darkness, since it’s easier logistically than making everything bright. From there, all you need to do are add touches of light to provide the contrast.
You can use simple things like blinds, for instance. Let the light from the outside seep in, washing areas of the room with light. Observe the interplay of the two, or even adjust the contrasts to get the mood you want to achieve.
Masters of chiaroscuro manipulate the sources of light to heighten or downplay certain elements. You can choose to draw the eye to certain parts of the body by placing a strip of light there between darker tones.
This is advanced stuff, though. Just as studying light and shadow is important in the core education of any artist, mastering chiaroscuro is best left to those with experience.