What is white balance? White balance (WB) is the process of adjusting the colors in an image so they are realistic and accurate. Our eyes have no problem with white balance, but cameras can have problems. As my students know I place emphasis on getting the exposure correct in the camera. It’s equally important to get WB correct and make the best choice in your camera.
If the WB is not correct your photos may have a blue, orange or yellow cast . These color changes are caused by the color temperature of the light sources in the photo and the camera’s difficulty in choosing the correct setting.
The chart below illustrates how the Color Temperature varies with different light sources.
Each of the six photos below were taken using different camera white balance presets.
The photos below were taken on a sunny day (no clouds) at about 10 AM. As can be seen the Auto WB (AWB) and Sunny preset yielded the similar results. Makes sense, right? Sunny day!
But what happens when you use the wrong preset? In the next four photos I used the Shade, Cloudy, Tungsten (domestic lighting) and Florescent settings. You will note that with each of these settings the photos have yellow or blue casts when compared to the photos above. Here the camera was set to the wrong WB for the lighting conditions.
OK, with AWB the camera did a good job of determining the correct white balance. So why not use it all the time? I would agree under some conditions it works well, however there are cases when AWB just doesn’t work.
The AWB photo (below left) gave a result that is too yellow.
In the photo you will see a card is propped up against the lamp.
Professionals sometime use something called a ‘gray card’ to assist in
getting a reference point for the correct WB. A gray card can be purchased, if you want, at most photography stores or online.
In the photo (below right) I used the gray card and the levels adjustment in Photoshop** to correct WB. I could have used the card to create a custom WB setting in my camera, but didn’t because I wanted to easily compare results. (See your camera manual for how to do custom WB with your specific camera)
I then re-shot the photo using the camera’s Tungsten WB setting as you see in the photo below, the results are similar to the Photoshop** corrected photo, though a little less yellow cast which personally looks more natural to me.
A second example below left, was taken by a friend, using AWB . The colors of the four rings are turquoise, purple, cobalt blue and red. As can be seen, the AWB didn’t do a good job of getting the colors correct. I learned the photo was taken with lighting from a table lamp. Using a white balance correction in Photoshop** I shifted the color temperature towards yellow, Tungsten. This improved the colors, but further color adjustment would be required in Photoshop** to be able to better distinguish purple and cobalt blue rings. If the Tungsten WB had been used in the original photo, colors would have been closer to the actual from the start.
Summary: What does this all mean? I believe the best choice is to use your camera’s WB, presets, i.e. Sunny, Shade, Cloudy, Tungsten and Florescent.
However, when taking photos outside in generally sunny, partly cloudy or a mixture of sunny and shady conditions AWB should work satisfactorily most of the time. Otherwise, I’d use the WB presets, your choice and preference. Explore the different WB’s available on your camera for different lighting situations and see what works best for you.
Using the WB presets is specially important for indoor available light photography i.e. Tungsten and Florescent. In the case of mixed lighting, where you have both natural i.e. sunlight and indoor lighting it becomes a little trickier. I’d recommend taking photos with both AWB and the appropriate WB for the indoor lighting. In the case of mixed lighting, the use of the gray card should be helpful. When using a flash indoors I’d recommend setting the camera for Flash WB. I’ll share my thoughts on flash photography in a future blog.
The links below will give you greater detail on How to Set a Custom WB.
** When I use the term Photoshop, I’m using it generically to mean any photo post processing software that allows for making corrections to your photos.
See my prior blog post Photo Processing Software if you wish additional information on photo processing software.
If you have any Questions please feel free to contact me
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