The key light is the most important light on set. It’s purpose isn’t just to illuminate the actor, but to help accentuate the emotion of the character in each and every scene. When looking at the key light, there are two major factors to consider: What direction does the key light come from, and how much does it wrap around the face?
- Direction – The direction of the key light is often guided by the direction of the ambient light on set, although the key light can be placed practically anywhere. As a general rule of thumb, try to avoid placing the light close to the axis of the lens. This will fully illuminate the front of the actor, wiping out the natural shadows that contour and shape the face. The result is neither flattering nor glamorous. The general guide is to position the key light roughly 45 degrees to the left or right of the axis of the camera lens… but how far?
- Wraparound – Sometimes a key light can be the harsh, untreated fixture, or it is heavily diffused. The degree of diffusion and wraparound depends heavily on the type of actor being lit and the overall cinematic look.
- Women (beauty/glamorous look) – Position a large key light such as a 2,000 watt tungsten, or a 1.2k HMI slightly more frontal than usual about 6-8 feet away from the actor, and raise the key light roughly 12″ above her eye line. Clip light diffusion like opal or 250 and 1/4 CTO (to warm up the light) to the barndoors. Then place a 6×6 heavy diffusion like gridcloth or bleached muslin 3-4 feet from the actor. This lighting tends to accentuate the cheek bones , lips and chin while filling in wrinkles around the eyes. Combined with a light pro-mist filter in front of the lens, this lighting is very flattering to women.
- Women (Standard look) – Try using a Kino-Flo wrapped with opal, and place 45 degrees from the lens axis. Then, place a 4’x4′ frame of 250 diffusion to further soften the light. This light, while slightly harsher than the beauty lighting tends to bring out more of the texture of the face, and creates a large eyelight.
- Men – (Standard look) – Use a 1k tungsten light through a 4’x4′ frame of 250 diffusion just off the lens axis as the main key light, then, add another 1k tungsten light through 4×4′ 250 frame focusing on the same side, but closer. This “stacked” key light approach creates a realistic look that both sculpts the face without accentuating wrinkles or skin imperfections.
- Men and Women (Sculpted) – An outstanding technique, especially when the actor’s eyeline is far from the lens access it to illuminate the far side of the actor’s face with a high, focused key. Assuming the actor is looking frame right, set up a 1,000w tungsten light through a frame of 250 diffusion just to the right of the camera. Then place a 650w tungsten light with 250 clipped to the barndoors focusing on the left side of the actor’s face. Raise the light so it is 2-3 feet above the actor’s eyeline. Notice how the key almost serves as a rim light, bringing out the contours and shape of the actors face. This lighting setup also creates an outstanding eyelight.
- Bouncing the Key – The key light doesn’t always need to be directly focused onto the subject. Some of the most beautiful light is reflected, and one of the most common ways to do this is by using a piece of 4’x4′ bead board, available at your local hardware store. The soft beaded texture of this styrofoam creates a soft diffused light without a lot of specularity.
- Low Ambience – For creating a key in low light situations, set-up a 1,000w or 2,000w light on a turtlebase with a 5/8″ baby pin adapter and focus it straight up into a 4×4 beadboard mounted at a 45 degree angle. Control the softness of the light by spotting or flooding the light source, and by walking the bead board closer or farther from the subject.
- High Ambience – For environments with high ambience, place the light fixture on a baby stand at eye level and aim it across the axis of the camera lens into a beadboard placed at a 45 degree angle. The light can be positioned as close as the outside edge of the frame, although a lenser may be necessary to reduce any reflection of the light source onto the camera lens.
- UltraBounce – To create an even softer key light, focus a large light source into a 6’x6′ UltraBounce. Although the light output won’t be as great as if the light were directly focused onto the subject, the reflected light will be softly wrapped around the subject, especially if the 6×6 is walked closely to the subject. Combine this tech with an additional key light coming from the side to add a little more edge to the look.