Most photographers who learn the basics of lighting usually take light for granted. Lighting seems pretty simple at first: If there’s an absence of light, just add a strobe. Isn’t that why we all love on-camera flash?! I’m joking. Learning how to give light motivation is truly the easiest way to create cinematic lighting, and it’s a lot easier than you’d think.
If you’re trying to master cinematic lighting, you’ll absolutely want to study the principles of lighting, but beyond that, you'll want to understand how to purposefully manipulate color, size, quality, direction, angle, etc. in order to create the illusion of ambient light in the scene. For example, the light that emanates from a table lamp without a lamp shade creates really strong, contrasty shadows when far away from your subject. If you were to put a lamp shade on the lamp, it would diffuse the light source, creating a subtly soft source of light, which will obviously depend on the opacity of the lamp shade.
You would not only expect that the light emanating from the lamp shade would be softer than it was before, you would also expect it to retain its direction. In the video above (at 0:54), I purposely use a studio strobe with a Phottix Luna Octa Softbox positioned so that it replicates the soft, directional light emanating from the lamp shade.
Alternatively, you could also use a strobe on low power on the opposite side of the subject’s face as a fill light. Unfortunately, as you see in the video, I don’t have the room to do so.
Giving light motivation is not only a great way to learn cinematic quality lighting, but also study the principles of light. If you’d like to learn more about lighting, I’d advise checking out The Technique of Lighting for Television and Film by Gerald Millerson.