lighting - Best fluorescent bulb color temperature for shooting people and interviews?

I have a small, ultra white matte 13x10 room that I need to photograph and film people in. Something like this. The most important thing to me is accurately depicting a person's skin color.

Yesterday I purchased some clamp work lights and a few 6500k CFL bulbs. However, after taking some test photos with these lights I noticed that the skin color of my subjects looked very white (and even green where veins where). It seems that this lighting is a bit much for people.

What is the correct temperature for shooting people in an indoor room? I also have some nasty, yellow soft-white (2300k?) and halogen lights.

Answer

The problem with fluorescent lighting isn't the color temperature, exactly. You can generally adjust white balance to account for that. If there's a green tint, that can usually be compensated for with manual white balance. But the poor color rendering is harder.

The problem is that by their nature fluorescent tubes only produce light in narrow ranges of wavelengths (depending on the composition of the gasses and phosphors used). Since colors in objects are in a sense only actually there if the matching wavelength of light can be reflected back into your eyes or camera, this means fluorescent lighting flattens color in weird ways.

This is one of those cases where the human vision system's magical qualities run us into trouble. Your brain adjusts for this so quickly that you don't really notice unless you've got a reference light source to compare to. (There's a cool little exhibit on this at the Museum of Science in Boston, if you're ever in my area.)

"Full spectrum" bulbs use a combination of gasses to cover more spectrum. But even then, it tends to be spiky and weird, not the wide incandescence of, say, the sun (or a traditional light bulb). Many fluorescent bulbs list something called CRI, or "Color Rendering Index". This isn't perfect — I don't think it's regulated, and it appears to be determined by each manufacturer, not independently. And the process / standard could stand to be updated to an approach using more rigorous scientific understanding. But, it's what we've got.

So, you want to look for bulbs advertising a CRI at least in the high 80s — 100 is perfect on the scale. There's lots more detail in the Wikipedia article on CRI.

Of course, you could avoid the problem by using incandescent (including halogen) light sources.