3-Point Lighting Technique
The three point lighting technique is a method used in visual media like video, film, still photography and computer-generated imagery.
This technique uses three lights called key light, fill light and back light. They are some "rules"/techniques that is the basics to have, like: if only using one light, that one becomes the key light; or if only have 2 lights placed, one is the key and the other one is either the fill or the back light.
Key Light
Is the main light. It's normally the strongest and has the most influence on the scene and normally is placed to one side of the camera/person, so in that side it's well lit and the other has some shadow.
Fill Light
This is the secondary light and is normally placed on the opposite side of the key light. It is used to "fill" the shadows created by the key light. It's usually softer and less bright than the key.
To achieve that, you have to options: move further away or use some spun.
Back Light
Normally is placed behind the subject. Rather than providing direct lighting like the 2 before, this one provides definition and subtle highlights around the person/object. This helps to separate from the background and provides three-dimensional look.
