Guides · Guide 10
How to draw a three-point lighting diagram
Three-point lighting is the standard starting point for lighting one person: a key to shape them, a fill to soften the shadow, and a back light to separate them from the background. Here is how to draw it so a crew can build it.
The three lights
The key
The main light. It gives the face its shape and decides the mood. It is usually the brightest unit and sits to one side of the camera, angled in toward the subject.
The fill
A softer light from the opposite side, to lift the shadow the key makes. It is usually dimmer than the key, so the shadow stays but is not black. The weaker the fill, the more dramatic the picture.
The back light
Also called a hair light or edge light. It sits behind the subject, usually high, and puts a thin rim of light on the hair and shoulders. It separates the actor from the background.
Where each one goes on the plan
Start with the subject and the camera. Draw a line from the camera to the subject. This is the camera axis. Everything else is placed around it.
- Key. Around 30 to 45 degrees to one side of the camera axis, on the plan. It lights the near-camera side of the face less and the far side more, which gives shape.
- Fill. On the other side of the axis, often closer to the camera, and set lower in power.
- Back light. Behind the subject, on the line pointing back toward the camera, often offset slightly to the side opposite the key.
These are starting points, not rules. The room will push back, and so will the actor. Adjust by eye and then update the plan to match what you built.
Heights matter as much as angles
A plan is a view from above, so it cannot show how high a unit sits. Write the height next to each one. As a starting point, the key sits above eye level, angled down so the shadow of the nose falls toward the opposite cheek. The back light sits higher still. The fill is usually near eye level or below.
Name them and label them
Call them L1, L2, L3 or Key, Fill, Back. Add the type of unit and its height. If a unit has a flag or a diffuser on it, note that beside it. A three-point setup is only three lights, but written clearly it can be rigged in a few minutes.
When three is the wrong number
Three-point is a method for a single subject facing a camera. Two people in conversation need a key for each, or a single wide key and a back light on both. A wide, moving scene needs the room lit instead of the person. Treat three-point as a place to start, then add or drop units as the shot asks.
Check it against the frame
Draw the camera's angle of view on the plan and make sure no light or stand is inside it. The back light is the usual offender, because it sits behind the subject and is easy to catch at the top of frame. If it is in shot, lower it, move it or flag it.
ShotPlots lets you place each light, set its type and height, and see its throw on the plan. The example above is a worked version with a key, a daylight fill, an edge and a practical. Draw one free, no account, nothing to install, or see a finished sheet and its PDF.