White Balance!------ Tungsten and Sunshine and Snow OH MY!

I'm hoping I can keep this entry shorter than the rest. Again, I'm going to snag my explanation of White Balance from the post about shooting Automatic vs. Manual.

White Balance - refers to the representation of colors in your image. Different light sources cast different colors on your subject. Lets say for example you had a piece of white notebook paper on the table and it was lit by a tungsten bulb (normal lamp). If there was no white balance adjustment, the image will appear to be very warm and orangey in color due to the color cast from the lamp. Your white paper won't look so white. Lets say it was under the light of a fluorescent lamp. These lights cast a blue color on your subject. The image will look cool and blue in color. Who wants blue or orange paper...or anything in between? Well you may want a color cast if you're going for an artistic effect, but by adjusting white balance whether automatically, or manually, the camera will warm up or cool down the image to bring that paper back to a nice white color.

Ok so lets start by going through some of the available white balance settings on many modern cameras.

AWB -Auto White Balance does it's best to detect what type of lighting is present and to correct for it. (ok for most situations, but far from perfect)

- then there's all the manual settings. I'll list the names of most and it should be pretty self explanatory. You're basically just telling the camera what lighting is present.

Sunshine, Shade, Cloudy, Tungsten, Fluorescent, Camera Flash

There is also a Kelvin option and a Custom W.B. option.

Kelvin is typically a measure of temperature. In this case how warm or cool the photo is measured in Kelvin.

With photography, the scale we use ranges from approx. 1,000 degrees kelvin (candlelight) to 10,000 degrees kelvin (north sky [blue light]). In between we have sunshine at about 5,500 degrees, household lightbulbs at about 2,500 degrees, early sunlight at about 2,000 degrees, and overcast daylight at about 7,000 degrees. These are just a few of the light sources and an approximation as where they fall on the Kelvin scale. So by choosing the Kelvin option on your camera you can manually set the color temperature of the photo. I typically don't use this, however there are times when I intentionally want to warm up or cool down a photo. You may want to warm up a sunset or sunrise or in the example below I wanted a unique color for my sky so I bumped up the Kelvin to I believe somewhere around 9,500k.

The option I use 95% of the time is custom white balance. To achieve a custom white balance, you first need a white balance target. The one I have is made by Photovision. You'll see a picture of it below. With this type of target you basically just take a photo of the target with the white side closest to your light source, set your WB to custom, then depending on your camera, go into the menu and choose custom white balance. It will likely bring up the last photo you took (of the target) and ask if you want to use this photo to set your custom white balance. You hit ok or whatever on your camera and presto, you've just corrected those incorrect colors with amazing accuracy. There are many other white balance targets on the market. For example, one you put over the end of your lens, aim at the light source, and proceed to follow the same instructions above.

Below is a before and after of a tungsten bulb in my hotel room. I've also included a relatively white sheet of paper to see the effects on white itself. It should be noted that the before photos were taken while using the Auto White Balance function, so as you can see, AWB is faaaarrrr from perfect.

White balance target by Photovision

Before W.B. adjustment

Target photo that we use to set our custom W.B. with

A shot of the target after setting the custom W.B.

After W.B. adjustment

I want to add a quick note about snow. If you're using AWB on snow, the combination of the snows reflectivity and the actual light can trick the camera into rendering the snow blue. In some cases this can be very extreme. If you don't have a WB target, you can point the camera at the whitest patch of snow (avoid shadows), take the photo, and then use it to set a custom white balance with. You're basically telling the camera that what's in the photo is true white. From then on, your snow photos should be much more color accurate.

And there you have it. White Balance in a nutshell. (or errr "From The Ground Up!)