It's Sunday morning and the worship leader wants to try something. He's chosen a slower song and he wants to bring the lights down slowly to create a more "worship-ful" environment. (His word, not mine.)
As the song comes to a close, the lights are down to almost 25%. The tech crew looks up at camera monitor and sees a frightening image. The worship leader is washed in a red glow. When he smiles his teeth are even red. He looks like he he's on stage in the underworld.
For a split second, the technical director hesitates. Does he put that image on the big screens? Calmly he calls out, "Bring up the announcement slides."
This team has learned a valuable lesson, just because it looks good to the naked eye, does not mean that it's going to look good to the camera. Sometimes white is not really white. Understanding the difference is critical to getting the best look from your camera to the screen.
A stroll though your neighborhood at night can revel some important differences in light color temperature that you may not have noticed. As your eyes adjust to the dark, observe the different colors of light around you. Those little solar lights in the garden seem to be more blue. The light coming from the house fixtures looks more orange. That kitchen window seems almost green. Those street lights look almost pink. Your brain tells you though that each of them is white light.
Scientists will tell us that light is a vast spectrum that ranges from what we see into the invisible or infrared and ultraviolet light. In between, is the entire rainbow of colors that are graded by their color temperature. The temperature come from the Kelvin scale which places typical tungsten stage lights at about 3,200 degrees (or 3,200K for short). Sunlight varies as it travels across the sky but is placed generally at 5,600K. HMI Spotlights can come up to 6,000K as do many moving lights. LED and fluorescent bulbs can range from 27-6,500K.
These are measured when the lamp is used at 100% power. If you dim the bulb, even a little bit, you change the color temperature.
While our brains correct the color coming into our eyes, your camera does not. Your camera simply records the color that enters the lens. Yes, digital cameras have an automatic white balance setting but if your location has multiple light sources, you might get some strange results. For example, you may notice that your image gets blue when someone opens a door or a moving light may change position and change the color.
The first key to getting a great image is to learn how your camera white balances. You will need to find something that is white, like a piece of paper, and place it in front of your camera. For a typical digital camera, there will be a setting in your menu or a separate button. With DSLR cameras, white balancing can be a little more complicated. Check your user's manual for the details. Make sure your white is being lit by the main source. Don't turn your camera onto a white wall, for example, that is not getting the same light as your main subject, the pastor worship leader or whoever is on camera the most.
The second key is to know your lights. Stand in the place of your main subject and notice which lights are hitting you the strongest. What is the most dominate light source? What kind of light is it? A tungsten? A spot? A window? Wherever possible, try not to mix the lights that are going to be on your main subject.
Fortunately, you can correct lighting color with some simple tools. Rosco, Lee Filters and others make gels, or thin plastic sheets, that go in front of the light to correct the color. For example, let's say that your main subject is being hit primarily with the tungsten stage lights but there is a point at which he make walk into the light of a florescent and gets a bit green for a moment. A sheet of Rosco's "Fluorofilter" wrapped around the tube will help correct the problem. (If you have a light that gets very hot, make sure the gel is away from direct heat because they will melt.)
You can also purchase large sheets of color correction that can cover an entire window or skylight. This is how the pros shoot indoors and keep the color even.
Another tool is to simply change the lamp or bulb in your lighting fixtures. Perhaps your issue is with those new compact florescent (CFL) bulbs in the house lights. A trip to your local big box hardware store will reveal a wide variety of color temperatures in florescent bulbs and even for those long florescent tubes.
If you were considering switching to LED light, some actually have adjustable temperature settings. You can add a few at a time to your current set-up by switching them all to the matching color temperature.
The third key it to work closely with whoever is working the light board. Whenever possible keep the lights at 100% when your camera is in use. If there is dimming involved, make sure the camera gets white balanced again. The rule of thumb is whenever the light source changes - white balance again.
