How to illuminate a green screen / Comoiluminar un chroma key

In this tutorial without video, i will explain you how iluminate a green screen.
The green screen is a visual effect, is used in films, TV...
It can be a blue screen it's the same but in blue.
Example:

In a green screen the best important is the lights.
If in a green screen there is a shadow the green screen it wont be right.

You need to illuminate it with patiently and with attention because at the slightest mistake it wont be wrong.

A guide tu illuminate it right: