The key light is the light that is most bright and most influential. For our thriller this would be used to reveal characters that hold in importance, for the audience to gather that this is the moment or action that should be view the most in order for them to understand completely what i occuring in the scene.
The back light
The back light helps counteract the effect of the key light, bu allowing the character or object look more rounded. This lighting would be highly suitable for our thriller as is will allow the characters to be anonymous and making the audience believe that this anonymous character is someone of good justice, but this may not be true, meaning that this type of lighting leaves the audience in suspence.
The filler light
The filler light will help soften the harsh shadows that the key and back lights create, more than one filler light may be used.

