Getting your whites white...
and I am not talking about the laundry.
White Balance (WB) in photography has to do with the accuracy of color in your image.
You might notice an image has a blue or orange cast to it..
for example the white snow might look bluish.
If you increase saturation,
you will increase the color casts as well.
Auto WB to Shade WB with additional adjustments.
Different sources of light have different color temperatures.
So white does not always look white in your photos.
While your eye naturally adjusts to the light temperature,
your camera tries to adjust, but may not always adjust correctly.
While choosing the correct white balance will enhance
the appearance and accuracy of your images,
it is critically important when shooting people.
Skin tones that look too blue or too orange are not only inaccurate,
but also not very flattering.
Above...Tungsten WB to Custom WB
Digital Cameras have white balance settings.
While most of the time I shoot in the Auto White Balance (AWB) setting mode
which allows the camera to choose the color temperature,
I also shoot RAW so I can easily correct incorrect white balance settings.
At other times, when I am shooting in the same light environment,
I might adjust my white balance settings as follows.
1. When shooting in a home environment with incandescent bulbs, your shots will appear warmer or more orangey. Selecting Tungsten in WB will cool the colors down.
2. When shooting under cool Fluorescent lights like in public spaces selecting Fluorescent setting will warm the shots up.
3. Daylight is kind of self explanatory...
4. When using the Flash WB setting the camera will add a touch of warmth to the photo.
5. Outdoors on a cloudy day things appear cool so selecting the Cloudy setting will warm things up.
6. Shade is kind of like shooting under a cloudy sky. The Shade setting will also warm the colors.
Light temperature is measured on a Kelvin scale.
The Kelvin setting allows you to set your own color temperature.
|Color Temperature||Light Source|
|2500-3500 K||Tungsten Bulb (household variety)|
|3000-4000 K||Sunrise/Sunset (clear sky)|
|4000-5000 K||Fluorescent Lamps|
|5000-5500 K||Electronic Flash|
|5000-6500 K||Daylight with Clear Sky (sun overhead)|
|6500-8000 K||Moderately Overcast Sky|
|9000-10000 K||Shade or Heavily Overcast Sky|
Custom White Balance is where the 18% Grey Card comes into the picture. You can read about that on Wikipedia.
As far as selecting Custom White Balance, check your camera's manual for directions. In a pinch, I have used a white tablecloth to select Custom White Balance. I am just telling my camera that what I just photographed should be white, and the camera adjusts accordingly.
And Yes, you can adjust your white balance in post. You will have more options if you shoot in RAW, but jpg shooters can still make adjustments. Here is an article about adjusting WB in post.
....And coming soon, how to play with white balance for some cool effects.
For those serious about correct color in digital photography, make sure you have your computer monitor calibrated. If your monitor color is off, then the images that look right to you will look wrong to others or when printed.