Light is likely the most important ingredient of any photograph. However, it’s not the amount of light, the brightness, that’s important. As long as there is any light at all, no matter how dim, it’s possible to take a picture. The quality of the light makes all the difference. It can be harsh or soft, it can have a distinct color, it can model the shapes of objects and cast interesting shadows. Light can be stunningly beautiful or utterly boring.
Painters have known this for centuries. And they often painted the same scene over and over again under different lighting conditions. As photographers we also need to understand light and how it can completely transform a subject. That’s why we are always chasing the light. Not always successfully, though.