It’s hard to describe how paramount light is. Ultimately, it is the only thing we see. But just as important the presence of light is, so is its absence. To talk about light we have to start in darkness so let’s jump straight into it.

Light is a visible portion of electromagnetic radiation, but in this article I’m not going to discuss any of the underlying details like wave-particle duality. Instead, I’ll try to explain how light creates so many beautiful effects seen in everyday life. In the demonstration below you can use the sliders to control the position and size of a rectangular light source.

Awesome explanation about Lights and Shadows. I am a big fan of Bartosz Ciechanowski work, his explanations are clear and have cool interactive examples.