Concerning White Balance (WB)
I had a friend visit over the holidays and we had a few discussions regarding topics that involved WB and stage / theatre photography, so I'm hoping this article helps a few people in understanding what WB is, regardless if you are in front or behind the camera or admiring photos. (This first article is basic WB, and the next article will be about Stage / Theatre photography and WB.)
It happens every now and then that after taking photos, and loading these images onto a computer, people take notice that the subjects have Greenish, Orange, or Blue tones. The scene that was shot did not look that way when the photo was taken, so what happened? The camera snapped a photo of the moment, but the camera, unless instructed to use a specific color balance, will use an algorithm with the colors present to decide how warm or cold the photo should be. ...ok, in English, the camera is giving you its best guess on what color temperature the existing light is. Light can be either warm or cold, tinted green, or anywhere in between. In some cases, the best guess your camera can offer is good enough, but with some good guesses, there will be terrible guesses that can leave skin tones less than flattering. For serious photographers that are trying to convey a feeling, or capture the moment, using the correct WB can make a big difference (or using a different WB to create a mood). Auto WB is fairly good in modern cameras, but relying on it may lead to inconsistent color tones.
White is white, what's the big deal?
White is white, but how many tones of white are there? A human eye sees a white car and your brain has marked that car as white; now look at a wall and your brain also says that the color is white, then look at a white shirt, a white refrigerator, white clouds, photo copier paper...they are all white, albeit different tones of white. Your brain is doing your white balancing for you.
When you take a photo with your digital camera, you will have to specify what temperature of light should be used for that photo. This affects all the colors of that photograph (and the next photos you take), not just white surfaces; the white color is just easier to reference. So if you set the incorrect WB, or if your camera uses a bad guess (Auto WB), your photo may result in strange skin tones, and the colors may just look "off" and unflattering.
Here is a sample photo with three different values set for the white balance. One of them is set to a WB value of daylight, one is set to Tungsten and one is a custom balance set from a white portion of the image (the letters). Can you tell which one is which?
The first image is the Custom Balanced image. The second is the Daylight balanced and the last one is the Tungsten balanced. The slight difference between the first two photos is the warmth that the Custom WB shot has compared to the Daylight balanced. Not such a huge difference, but adds up to the final image nonetheless.
How does this affect skin tones? Check out these next set of images. One is balanced for Shade, one for Flash and one for Tungsten. Skin tones are less forgiving...unless blue or orange skin is what you are looking for. The image balanced for Shade can work as the warm tone is acceptable, but if the skin tone is a big deal for your clients, then be aware of that concern.
So what to do to prevent or correct this?
If shooting in JPEG format, you will want to set your WB prior to taking the photo. Locate the WB settings on your camera and specify the type of light you are shooting in (daylight, flash, fluorescent, etc).
If shooting in RAW format, you can use any current post-processing software to adjust the WB when processing. If you like to crank up the colors by adjusting saturation and making blue skies really blue, and green grass almost-neon-like; please do take care that you preserve the correct skin tones. Deep colors are great, but orange skin just reeks of over-processing. If you are not familiar with how to adjust WB in post processing, I would suggest going to YouTube and locating a tutorial for your software.
There are companies that sell white balance assisting devices that can range from $ to $$$. Some people will swear by them and some people will say use a Pringles cap or any translucent food container to achieve the same thing. If you shoot RAW, just do it in post processing. Save your $ and get a good photography book instead. If you shoot JPG, look into using your camera's Custom White Balance feature. Learn and master your gear instead of buying more gizmos.
So Hopefully that gives you an idea of what White Balancing is.
Drop me a message if you have any questions or comments.