Direction of Light
Written by Abin Alex and Anu Joseph.
Abstract
A practical guide to the direction of light: how it is measured from the camera, what front, side, top, back and under light do, the 45 degree working angle, the sun as a clock, measuring the sun with a shadow and two practice exercises, with four diagrams and one table.
Keywords: direction of light, front light, side light, back light, top light, 45 degree key light, sun direction, shadow length, golden hour
How is the direction of light measured?
Short answer. From the invisible line between the camera and the subject, not from the room or the clock.
- Direction is measured from the axis, the line from the lens to the subject. It is not measured from the subject, the room or the clock. Figure 1 shows the dial.
- A light near the axis, behind the camera, is front light. At 90 degrees to the axis it is side light. Behind the subject it is back light. Above is top light and below is under light.
- Turn the camera and the compass turns with you. The light has not moved, you have. Walk 90 degrees around the subject and front light becomes side light. Walk further and it becomes back light.
- There are two ways to change direction. Move the camera or the light, or wait and let the sun move for you.
Place one lamp. Walk the camera in a half circle around the subject and watch front light become side light and then back light.
On a set the same rule applies. The camera position decides what every light is called.
Cham tipSay the direction from the camera, never from the room.
Cham taskPhotograph one subject with one lamp from three camera positions and name the direction each time.
Check yourself: From what is the direction of light measured?
From the line between the camera and the subject.
What does each direction of light do?
Short answer. Front flattens, side sculpts, top hardens, back separates and under unsettles.
- Front light comes from near the camera. It is even, open and honest, and it is flat. Shadows fall behind the subject where the camera cannot see them, so texture and depth almost vanish (Child and Galer, 2008, p. 18). It is used for news and ID photos, on-camera flash and ring light.
- Side light comes from about 90 degrees to the axis. One half of the subject is lit and the other half falls into shadow. It gives the most form and the most texture, and on a face it is split light (Grey, 2004, p. 44). It rewards interesting surfaces and punishes skin you wanted smooth.
- Top light comes from high above, such as the midday sun or an overhead fixture. Shadows drop straight down: dark eye sockets, a nose shadow on the lips, bright hair and a dark chin. It is harsh for faces, but it is the normal light of every open landscape.
- Back light comes from behind the subject, so the camera side gets no direct light. A bright rim traces the hair and shoulders and lifts the subject off the background. Expose for the light and you get a silhouette. Expose for the face and you get a glowing halo. It separates subject from background better than any other direction (Child and Galer, 2008, p. 18).
- Under light shines upward from below the subject. Every familiar shadow is inverted: a bright chin, dark eyes and shadows climbing the wall. It almost never occurs in nature, so the viewer feels unease before they know why. Table 1 compares the five.
| Direction | Look | Feeling | Seen in |
|---|---|---|---|
| Front | Even, flat, little texture | Open, honest, informational | News, beauty, catalogues, ID photos |
| Side | Maximum form and texture | Character, texture, drama | Window portraits, noir, product texture |
| Top | Harsh shadows straight down | Harsh, oppressive, exposed | Midday exteriors, interrogation scenes |
| Back | Bright rim, separation | Romantic, mysterious, glowing | Golden hour, silhouettes, dream scenes |
| Under | Inverted shadows | Wrong, unsettling, threatening | Horror, firelight, footlights |
Table 1. The five directions of light compared.
Light one face from each direction in turn. Photograph each and write the feeling in one word.
A thriller uses top and under light. A romance uses back light and side light.
Cham tipDirection chooses the sentence. Quality and colour choose the tone of voice.
Cham taskShoot the five directions on one subject and label each frame with its feeling.
Check yourself: Which direction separates a subject from the background best?
Back light.
What is the 45 degree working angle?
Short answer. Key light 45 degrees across and 45 degrees up gives form without harshness.
- Between the compass points sits the angle that carries most of portraiture and cinema: the key light 45 degrees across from the axis and 45 degrees up above the eyes.
- It has half of the openness of front light and half of the form of side light. The shadow edge sits gracefully on the face, and texture shows without being punished.
- The sun is at about this height and angle in mid-morning and mid-afternoon, which is why those hours flatter almost everything. When in doubt on set, start with the key at 45 degrees across and 45 degrees up and adjust from there.
Place the key 45 degrees across and 45 degrees up. Move it 10 degrees each way and compare.
Most classic setups are a variation on this start.
Cham tipStart at 45 and 45, then adjust for the mood.
Cham taskLight a portrait at 45 and 45, then change one angle at a time and note what changes.
Check yourself: Where does the working key sit?
45 degrees across and 45 degrees up.
Why should a picture show one main light?
Short answer. Natural pictures show one family of shadows. Fill lifts the shadows but never casts a second one.
- We evolved under a single sun, so pictures that look natural obey it, even when five lamps are burning (Grey, 2004, p. 11). Good lighting reads as one direction with one family of shadows.
- Fill exists, but it stays anonymous. A second or third light lifts shadows and rims edges, but it must never cast a second shadow that contradicts the first. Several nose shadows are the mark of an amateur (Grey, 2004, pp. 11-12).
- Test any setup at a glance: count the cast shadows of the nose. One is craft. Two is a mistake.
Add a second light and look under the nose. If you see two shadows, move or soften it.
On a set, every extra light is judged by whether it adds a second shadow.
Cham tipCount the nose shadows before you shoot.
Cham taskBuild a three light setup that casts exactly one nose shadow.
Check yourself: How many nose shadows should a good setup show?
One.
How does the sun act as a key light through the day?
Short answer. The sun rises in the east, peaks at noon and sets in the west, so one camera position gets every direction in a day.
- The sun follows the same route every day: it rises in the east, climbs to its highest at noon and sets in the west. It is a key light that repositions itself every hour.
- Figure 2 gives an example with the camera facing west and the subject facing the camera. From 7 to 9 am the sun is behind you, front light. From 9 to 11 and from 2 to 4 it stands beside you, side light. From 11 to 2 it is overhead, top light. From 5 to 7 pm it faces you, back light.
- This table holds for one fixed camera direction. Face a different way and every entry shifts. You cannot move the sun, but you can choose which way you face, and that decides the lighting plan for the day.
- A shadow always points away from the sun. At sunrise the sun is in the east, so shadows point west. At sunset the sun is in the west, so shadows point east. Reverse any shadow and it points at the sun, which tells you the direction of the light even in a photograph you did not take.
- The length of a shadow follows the height of the sun (Figure 3). A low sun gives a long shadow and a high sun gives a short one. The shadow runs long, short, long, with the minimum at local noon. Long shadows sculpt texture and drama. Short shadows mean flat, hard top light (Child and Galer, 2008, p. 18).
Stand in one spot at three times of day and photograph the same subject. Note where the shadows point.
A location scout reads the sun route on the first visit and plans each scene for its hour.
Cham tipPick the camera direction first, then let the hour pick the light.
Cham taskWrite the direction timetable for a camera facing east.
Check yourself: Which way does a shadow point at sunrise?
West, away from the sun in the east.
How do you measure the sun with a shadow?
Short answer. The tangent of the sun elevation equals the object height divided by its shadow length.
- A shadow and a tape measure are enough to find how high the sun is. The object is the vertical side of a right angle triangle, the shadow is the base and the sun ray is the slope (Figure 4).
- The formula is tan of the sun elevation equals object height divided by shadow length. A 7 m pole throws a 10 m shadow, so tan θ is 7 divided by 10, or 0.70, and θ is about 35 degrees. A shadow longer than the object always means the sun is below 45 degrees.
- At any single moment everything under the same sun has the same height to shadow ratio. If you are 5 ft tall and cast an 8 ft shadow, and a tree casts a 100 ft shadow, the tree is 100 times 5 divided by 8, or 62.5 ft tall. The same trick tells you the height of a building before you ask to rig a light on it.
Measure your own shadow and the shadow of a tree at the same moment. Work out the tree height.
Sun charts and shadow measurements are how a unit plans exterior shooting hours.
Cham tipMeasure both shadows at the same moment.
Cham taskPlace a white object on chart paper marked N, E, W and S. Trace its shadow every hour, graph the length against time and write 800 words on the best hour for a portrait.
Check yourself: What is the formula for the sun elevation?
tan θ equals height divided by shadow length.
What practice builds the eye for direction?
Short answer. Sweep one desk lamp through an arc indoors, then trace shadows hour by hour outdoors.
- Practice 1 is the desk-lamp arc, done indoors. Before you chase the sun, rehearse every direction with one lamp on your desk. Move the lamp, never the object or the camera. Sweep it through a 180 degree arc from the far left to the far right of the subject and watch the terminator travel and the shadows swing.
- Repeat the arc at three heights: once at subject level, once 45 degrees above and once slightly below. Photograph each position and make a contact sheet. On any three frames, label the direction and the mood it creates. Submit the contact sheet of the arc and three labelled frames.
- Practice 2 is the shadow chart, done outdoors. Place a white object on chart paper marked N, E, W and S in open sun. Every hour, trace the shadow, write the time and photograph the chart from the same position with the camera angle unchanged.
- Plot shadow length against time and note the swing of direction. Mark where the two longest and the shortest shadows fall. Write 800 words on what happened to length, direction and colour through the day, and which single hour you would choose to shoot a portrait, defended with your own data. Submit the traced chart, the hourly photos, the graph and the 800 words.
Do the desk-lamp arc tonight and the shadow chart on the next clear day.
The same arc is how a gaffer tests where to place a key before the actor arrives.
Cham tipMove the lamp, never the subject or the camera.
Cham taskSubmit the contact sheet of the arc with three labelled frames, then the shadow chart with graph and 800 words.
Check yourself: What do you move in the desk-lamp arc?
Only the lamp.
Questions beginners ask
How is the direction of light measured?
From the camera to subject axis. A light near the axis is front light, at 90 degrees it is side light, behind the subject it is back light.
What is the best angle for a key light?
45 degrees across from the camera axis and 45 degrees up above the eyes. It gives form without harshness.
Which way does a shadow fall?
Always away from the sun. At sunrise shadows point west and at sunset they point east.
Why is midday sun harsh for portraits?
It is top light. Shadows drop straight down into the eye sockets, under the nose and under the chin.
How do you find the sun height from a shadow?
Divide the object height by the shadow length and take the inverse tangent. A 7 m pole with a 10 m shadow gives about 35 degrees.
What is a good exercise to learn the direction of light?
Move one desk lamp through a 180 degree arc around a subject at three heights and photograph each position.
References
- Child, J. and Galer, M. (2008) Photographic lighting: essential skills. 4th edn. Oxford: Focal Press.
- Grey, C. (2004) Master lighting guide for portrait photographers. Buffalo, NY: Amherst Media.
Further reading
- Hirsch, R. (2008) Light and lens: photography in the digital age. Burlington, MA: Focal Press.
- Hunter, F. and Fuqua, P. (1997) Light: science and magic: an introduction to photographic lighting. 2nd edn. Boston: Focal Press.
- Marr, D. (2004) Beginner's guide to photographic lighting: techniques for success in the studio or on location. Buffalo, NY: Amherst Media.
How to cite this guide. Alex, A., & Joseph, A. (2026). Direction of light: A guide for photographers and cinematographers. Creative Hut Academy. https://creativehut.org/library/direction-of-light/
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