A viewer rarely notices light directly — and that's exactly why it's so powerful. It shapes feeling before we have a chance to think.
Ask a random viewer what they liked about a film and they'll name the story, the actors, the music — almost never the light. Yet light is the first thing that tells us what to feel. It works ahead of the plot, on a level we don't control. That's its power and its treachery.
Light as a point of view
Where the light falls from is already a choice by the author. Soft and diffuse, and the world becomes vulnerable, human. Hard and high-contrast, and the same frame turns into a threat. The cinematographer doesn't "light the scene"; they decide how we'll feel about it, before the first line is spoken.
Good lighting doesn't show what's happening. It shows what it means.
Darkness as material
Just as important is what the light hides. Shadow isn't an absence of image but a full instrument. What the cinematographer leaves in darkness can say more than what they bring into the light. A frame with half a face sunk in shadow is already drama, without a single word.
How to watch more closely
Try this on a single scene: mute the sound and forget the plot — just follow the light. Where it comes from, what kind it is, what it conceals. Very quickly you'll see that half the film's emotion arrives from here. And then cinematography stops being a "pretty picture" and becomes what it actually is — a way of thinking in images.