Getting the colors right!
Wednesday, January 13th 2010 @ 6:21 PM (not yet rated)
The "white balance" needs of digital cameras can be SO confusing. What is it, anyway? Light is a "spectrum" ... and is how we "see" color, as the varius wavelengths we see as different colors. "Temperature" is the term used to describe the mix of colors in the light falling on the scene in front of you. That "temperature" is the important thing!
Dark cloudy afternoons have a very "blue" light (up to 10,000 kelvin or "k"), and standard household bulbs are very red-yellow (around 3200 "k"), both compared to summer-time noon (around 5200 "k").
Here's the deal: most camera's have a photo-sensor that is designed "for" light of about 4000 to 4600 "k". It will be the most accurate in color-response in that light. For light "warmer" or "colder" they use little adjustments that amplify or reduce the signal from the camera's sensor in one or more of it's three channels, Red, Green, and Blue. Why 4000k? Note: it's about in the middle of the light color-temp range. Also note: it is MUCH closer to Daylight than to "tungsten", the standard house-hold bulbs.
It is much easier to get good (or at least decent) colors in tungsten lighting by setting a manual color temp rather than using the camera's "tungsten" or "auto-white balance" settings if you can. I would suggest starting with a setting of 3000k for tungsten lighting, and adjusting to taste from there.
Also, be sure to get a well-exposed image! You are "shooting" so FAR from the camera's "native" color, it is amplifying signal like crazy to "balance" to the right colors. The SLIGHTEST under-exposure (darker than "normal") will result in TONS of noise in the image!
And those new "compact flourescents"? Good luck ... their basic color temps can vary from 3800 to 6000 "k", but their color output is SO uneven, that one shade of a color is WAY strong but farther along the "hue" of that color is near non-existant. And their "tint" or "hue" components are even harder to sort out! So, your greens might be dull and your reds over-powering yet ... odd. Though blue may look pretty good but those faces ... purple-yellow-blue skin just never looks ... right!
Making it worse, the colors vary so much from batch to batch of the same light within one maker, and there are so many "flavors" of these lights, that chances are every compact flourescent in the room will have it's own odd color output! This results in situations where going back to flash for your main exposure, or at least "bouncing" a little flash off a neutral-colored ceiling, may vastly improve your photo's colors.