3-point lighting, a technique used in traditional photography and cinematography, works by illuminating a subject using three different light sources. This technique gives you total control over the strength and position of each light source. 3-point lighting is used in many productions, including docus, reality TV, and narratives because the effect provides context even before the subject utters a word.
The Basic Setup of 3-Point Lighting
The 3-point lighting includes the key light, fill light, and back light. Here is a typical lighting setup:
A key light is the main source of light. This light source shines on your subject the most. Although there is no standard wattage for a key light, watt ranges from 150 watts to 10k watts, depending on the project. The key light is often set to the side of the camera, angled between 15 and 45 degrees. From the side, raise the key light above the camera. This way, the light hits the subject from 15 to 45 degrees higher than the camera angle, which is pleasing to the eye.
When it comes to the position of the key light, the subject usually stands in between the camera and the key light. The key light illuminates the front side of the subject, including the face. The strategic position of the key light adds drama and interest to the scene.
Fill light is used to adjust the contrast between the right and left sides of the subjects to fill in the shadows left by the key light. Because the key light is set at an angle, shadows appear on high points of the body. Fill light produces a less powerful beam of light to soften the shadows cast by the key light. The point is to not eliminate shadows completely but to reduce the strong illumination of the key light for a softer transition of light from one side to the other.
To set your fill light, place it on the opposite side of the camera as the key light. Point the light on the subject at a similar angle as the key light. If the brightness of the fill light is too much, you have to use filters to diffuse it. You could also adjust the strength of the light by moving the fill light further or closer to the subject.
Rim Light (Backlight)
Rim light is set in the back to separate the subject from the background. It provides a soft glow to the image from the back. The wattage of a back light is similar to that of a fill light but sometimes, less powerful light is enough to highlight the subject from the back.
When done right, the back light creates a beautiful “halo” effect on the subject’s head and shoulders. This effect separates the subject from the background. Backlight adds depth to the shot and improves the quality of your work.
You could set the backlight directly behind the subject, as close as possible to the subject’s back or hang it from above the back of the subject. Adjusting the rim lights lets you create a bright, clear outline that highlights the top or side edge of the subject so don’t be afraid to try different angles to get the lighting right.
Although 3-point lighting is comprised of actual lights, you could apply the same principle using the sun, some diffusers, and a reflector. But to make your work as polished as possible, you must have the ability to control the strengths and positions of each point of light.
Lighting Tips and Tricks
3-point lighting is a popular technique because it gives utmost control of how a subject is illuminated. This setup is ideal for creating a studio type lighting effect, if you have to light a single subject or if you’d like to create a still image. To optimize this setup, try any of these lighting tips:
The setup always starts with the key light and to ensure excellent results, the one light scene (using just the key light) should have a good balance and contrast between light and dark. The shading should use all the grays in between. The illumination from your one light should look close to the final render except for the pitch-black shadows and harsh contrast. The fill light will then soften the shadows and balance the contrast.
Shadows from a fill light are often optional or skipped entirely. The key light to fill light ratio is 8:1. For a shadowy effect, use 1/8th of the key light’s brightness. If you are using several fill lights and the illumination overlaps, their sum should not compete with the key light.
You could mimic reflected light by tinting the fill light color to match the color of the environment. Fill lights could also be set to not cast specular highlights.
Backlights are often used to cast shadows. To create a rim of light around the top or side of your subject without affecting the background, try light linking. Link the rim lights only with the main subject being illuminated.
If the illumination is too harsh then you have to diffuse the lights. A diffuser will come in handy if the lights are too bright. The diffuser softens the light so the overall setup creates a natural-looking light.
Create a softer light effect using a bounce sphere. The bounce sphere has a reflective surface that softens harsh light. You could also use a bounce sphere as a fill light so you don’t have to carry several lights. Just set the bounce sphere next to the subject and let the light bounce from the key light on to the subject’s face. This tool will come in handy if you don’t have a complete light kit.