Producing Conference Video Pt. 2: Lighting and Audio

The Technical Side of Ligthing for Video

Lighting for video is more technical than it is creative for a lighting technician. The goal is rather simple: create as even a wash of front lighting as possible while having the subjects pop from the background using backlights. The former is a matter of tweaking with lighting positions and overlap to make sure that there are no hot spots or dead spots on stage. A light meter can be used on stage to measure precise light output but generally having a stand-in walk around the stage while you follow them with a video camera set to the same manual exposure will tell you when you need to make adjustments. There are no rules to how precise you need the light levels to be but if you can avoid having to make iris adjustments you are in great shape.

Ultimately, what matters the most is avoiding bright spots next to dark spots because that is where your talent will inevitably choose to stand and then proceed to rock back and forth in and out of the light.

Making Your Subjects Pop

Making your subjects pop from the background is important to create separation. Separation differentiates your talent from the background and is critical when they are wearing similar colors to the background. Dark jackets or dark hair against a black backdrop are the most common culprits and the effect is similar to the high contrast ratio problem in that your subject's face will appear to be floating on-screen sans body. The fix is using one or a combination of backlights. Besides the obvious that front lights are physically in front of the speaker and back lights behind, they are similar in that on camera, their visible light is in the front. Front lights increase light overall on the side facing the video camera while back lights contour the subject by adding light only to the edges.

Often times, the final call of lighting decisions is not yours to make so there are a few compromises you can negotiate. One of the lighting decisions that causes me the most problems is the use of a follow spot-a spot light that is supposed to follow the talent as they move across the stage. The reason they cause me problems is that the operators often have the throw too narrow to cover the entire body of the talent from head to toe, don't allow additional room for movement and allow the talent to momentarily leave the spot, and aren't always the smoothest at panning.

I've already discussed what happens in a high-contrast-ratio environment when the talent leaves the light but the curious thing that happens when the light technician has jerky pans is that the live audience hardly notices it but on video it gives the illusion that the camera operator is the one who is not smooth. To solve this problem I negotiate to have the follow-spot on a wider setting and stress the importance to the follow-spot operator of not allowing the talent to leave the light, even if it is just their arm. I find that giving them a video monitor so they can see how important their role is in determining production values of the video is both empowering and effective in getting them to work in concert with you.

Adjusting Contrast Ratio

The last step in bringing the contrast ratio within your video camera's range is to increase your video camera's range. There are two functions in most prosumer and professional video cameras that will do the trick. The first is called "knee," and it works to digitally knock down the brightest areas, or highlights. The second is black stretch and it works to digitally increase the brightness of your darkest areas, or shadows. Think of the black stretch as gain but instead of brightening up the whole image, whether it needs it or not, it only applies gain to the shadow areas that need it the most. Together they help to extend the exposure latitude of your video camera.

LED lights are really changing the stage lighting game. They run with significantly lower power consumption requirements. I started seeing them being introduced as on-stage LED up-light canisters, useful for adding light to the backdrop. Most can be programmed to throw both white light, colored light, or cycle through the entire range of colors. I find they are especially useful against backdrops to separate them from your talent.

The benefits of low power consumption go beyond the challenge of finding enough circuits to power your lights. Low wattage lights also heat-up less and radiate less heat as a by-product, keeping the room cooler for audience and crew alike. When my wife, Amanda, and I were on our honeymoon in Mexico's Mayan Riviera, our resort had nightly stage productions in their covered outdoor theatres. One night one of the lights exploded, raining hot glass down on the spectators who were right in front of us. Fortunately the metal scrims caught the larger pieces but a few small ones got through. This isn't a problem with LED lights, because they don't heat up anywhere close to as much as traditional lights. Unfortunately, up until recently, LED lights weren't available in high-output models so traditional high-wattage lights lit up all but the smallest stage environments.