Our generation is used to bright lights. From staring at our bright computer screens for ten hours a day, watching our huge televisions, attending bright concerts with intense lighting effects, the zeitgeist of our time is “Louder and Brighter”! But is “brighter” really better? Most people do not take into consideration are the more subtle concepts of lighting visibility.
One of my favorite stories on this concept had to do with a student of mine working on a production at the university. The show was in a proscenium theater and the director kept complaining that he could “not see or hear the actors”. When I arrived, there must have been over 300 foot-candles of light projecting onto the actors. Although the actors were sweating under the lights, they were indeed difficult to “see and hear”. How can that be?
One of the primary functions of light is “visibility.” Light must be present to reflect the wavelengths off of an object so that our eyes can perceive it. Although our eyes are very sensitive to light, we still need a minimum number of lumens for light to be perceived easily by the eye. But intensity alone will not create effective visibility. Like in my student's design, throwing lumens on stage is not enough. Lighting designers must understand how to use the contrast of light and shadow, along with the angle of light to create effective visibility.
When the director complained that he could not see the actors, my student was adding light by exclusively using front light. Unfortunately, direct front light is the worse angle of light to use for visibility. When you use direct front light very few shadows are created on the face, making it difficult to see the modeling of the actors' expressions. We read expressions on the actors' faces to help us understand and “hear” the actors. This is why when faces are washed out with front light; we usually have difficulty understanding what the actors are saying.
A more affective approach to lighting actors is with a combination of diagonal front light (from a Box Boom), high side light (from the ends of an overhead lighting batten which hits high and across the actor's face, revealing shadows of the angles and curves on the face, and highlighting the lips), and a small amount of direct front fill light (from a low cove or balcony rail, to reveal the eyes). This emphasis on “modeling” the actor's face with light and shadow is much more effective than cooking the actor with intensity.
Effective visibility depends on good contrast and balance between the foreground and background. It is important to understand that when you add intensity, the irises in our eyes close a bit to adjust for the brighter light. When our irises close, everything that is less intense than what your eyes are focusing on (like the background, video projections, etc.) will appear much darker to the eye. This is called “relative intensity”. When an imbalance occurs you may be tempted to just add more light to the background to balance the visual composition. However, by doing this you add more lumens to the viewing space, making our irises close even more.
A much better solution may be to take light away from the brightest object, allowing the eyes to balance the foreground and background. It's amazing how effective it is just to take the intensity down, instead of adding. Plus you save energy by doing so.
When balancing the lighting for video for a broadcast event, always look at the video feed when working with the lighting, as the camera is the eye of the audience.
When working on productions that incorporate live and broadcast audiences (like most worship services), you have to take both into consideration. This is where I think many worship lighting designers lose focus. You can still light for the camera, but also look at the lighting from the audiences' perspective. Go out to the last row of the audience and see if people look clear and defined under the light. You may have to add a little intensity to balance it for both broadcast and live.
Also look at the intensities of the IMAG projection surfaces. Sometimes they may be so bright that it makes the stage lighting look dim. Again, it's that “relative intensity” thing that happens in our minds. If you have super powerful projectors, lowering their intensity may help.
It is also good to consider how much ambient light is in your house of worship. The more light that emanates from windows, adjacent rooms, or even your houselights, the brighter your stage lighting must be. Try turning those ambient sources of lights down, and get better window shades. For houses of worship that incorporate natural light, higher intensities on stage will be required.
Understanding the concepts of effective visibility, contrast, relative intensity, and how our eyes and minds respond to physical light will help you create an amazing amount of focus and visibility to your design. Hopefully you will never again hear the words: “Why is it so dark?”
