The planes of the head

Artists simplify a head into planes (a flat forehead, side planes of the temple, the wedge of the nose, the box of the jaw) because light behaves on a plane as it does on a cube: one plane, one value. A real skull shows the same thing in bone.

With the planar head you see the planes cleanly; with the skull you see why the face has them. Light from above and the side makes the planes read most clearly.

1

On the planar head each flat facet gets one value: count how many different values you see.

AZ 60° EL 30°

darkest 32%average 56%brightest 79%lit 50%

2

The brow overhangs the eye sockets, so the sockets are dark whenever the lamp is above.

AZ 0° EL 70°

darkest 36%average 53%brightest 84%lit 39%

3

The nose is a wedge: one side lit, one side dark, a small shadow underneath.

AZ 60° EL 30°

darkest 28%average 53%brightest 82%lit 47%

4

On the skull the cheekbones catch the light and the eye sockets and nasal opening are the darkest shapes.

AZ 0° EL 70°

darkest 28%average 51%brightest 82%lit 39%

The head is cut into flat planes. Each plane takes one tone, so move the lamp and see the planes of the forehead, the brow, the cheeks and the jaw change in turn.

Each card is one lamp position: the picture it makes, a diagram of where the lamp stands (azimuth is measured from the camera: 0° is a lamp at the camera, positive turns it toward the picture’s left, 180° is straight behind; elevation is the angle above the table), and the values measured on the form itself.

From the left

AZ 60° EL 30°

darkest 32%average 56%brightest 79%lit 50%

Load in the room →

From above

AZ 0° EL 70°

darkest 36%average 53%brightest 84%lit 39%

Load in the room →

From the right

AZ -60° EL 20°

darkest 32%average 56%brightest 80%lit 48%

Load in the room →

Choose the planar head, drag the lamp from far left to far right, then repeat on the skull and the male bust. Notice how the same lamp position gives you the same pattern of planes in all three.

Open this lesson in the Light Study Room

The room opens with the shape and the first set-up already loaded, and the same diagram you see here follows your lamp as you move it. Drag the lamp’s marker on the picture, or move it on the pad, and switch between Picture, Light only, Surface and Shadow. Or open it from inside the studio: the Study button in the bottom bar, then Academy lessons. The Light Study Room is a separate classroom for learning light on 3D shapes; when you are ready, “Send to studio” takes the shape into the main editor.

Exercises

1. On the planar head, count the number of distinct values you see from the left. Then from above.
2. On the skull, find the lamp position where both eye sockets are completely dark.
3. Compare the nose on the planar head and on the bust: where is the shadow plane?

Michelangelo →Da Vinci →Rembrandt →