White Balance - Auto vs Shot vs "A" auto adjust

I shoot a lot of natural light scenes outdoors, many times in situations where I cannot use a gray card beforehand for my white balance starting point. In some cases, I start with the camera's auto white balance setting that C1 will pick up. In other cases, I click on the "A" auto adjust button and it gives me a nicer place to start with, especially in certain mixed lighting scenarios. But there are times when clicking on the "A" will give me very wacky results, particularly in all sunlight or sunlight mixed with shade - wacky meaning it will be almost entirely green tinted. Example:

WB Shot:
http://www.terencepatrick.com/storage/c1-shot.png

WB "A" auto:
http://www.terencepatrick.com/storage/c1-auto.png

Is this a bug or does the "A" setting look for something not shown in certain photos?

Also, why is the "shot" preset and the "auto" preset (in the WB drop down menu) giving the same results? Shouldn't the "auto" preset be the same as the "A" auto adjust?

Paul Steunebrink

May 18, 2011 19:58

[quote="Terence2" wrote:
...
Is this a bug or does the "A" setting look for something not shown in certain photos?

A bug or not, but any kind of automatic adjustment can be influenced by over exposed areas or color dominants. "Auto" is just a averaging trick, one way or the other.

[quote="Terence2" wrote:
Also, why is the "shot" preset and the "auto" preset (in the WB drop down menu) giving the same results? Shouldn't the "auto" preset be the same as the "A" auto adjust?

No. The "shot" preset refers to the camera preset, whether this was auto, daylight, shadow or fixed Kelvin value. You don't have to remember your camera setting, just go to "shot" to go back to your starting point. It actually reads the white balance settings the camera wrote into the metadata section of your raw file. So when you shot with auto white balance, the preset "shot" will be the same as "auto".
The A or Auto Adjust of Capture One has its own metrics to auto white balance, which is not necessarily the same (more probably not) as your camera manufacturer did put in it's hardware. So expect CO's Auto Adjust (for WB) never be the same as your camera. Confusing? Think of your raw file as a new starting point once in your computer. Your camera does not exist anymore and it is Capture One (or any other raw software package for that matter) who determines what happens.

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