Does changing white balance in post reduce image quality when shooting RAW?
Asked 12/13/2011
6 views
2 answers
0
If I shoot RAW, can I safely correct white balance later in Lightroom or similar software without losing image quality? Is this effectively the same as setting the correct Kelvin value in-camera?
For example, if I use an older flash that doesn’t communicate white balance to the camera and the photos come out too blue, is it fine to fix that in post? Or is it still worth trying to get white balance close in-camera, especially if the light is changing?
Originally by Photography Stack Exchange contributor. Source · Licensed CC BY-SA 4.0
Photography Stack Exchange contributor
14y ago
2 Answers
30
No. If you shoot in RAW, there is nothing lost.
In fact, in RAW, the white balance you set in-camera is nothing but advisory information to the post-processing software. A different multiplier is applied differently to the red, green, and blue channels during RAW conversion depending on the setting, and if you're doing that conversion from a RAW file, you can always choose to do it differently unless you destroy the original.
The only exception is when the lighting is so strongly colored that it affects the metering oddly. If you have the white balance set in camera, it will apply to the displayed histogram. Some people really are concerned out about this, and have invented the idea of "uniwb", a custom white balance designed to balance the three color channels evenly. If you are very meticulous, and if you are trying to make the most of extreme scenes, you may be interested in seeing if that helps. (You probably also want to reduce the default contrast settings, for the same reason.)
Also, see this related question: If shooting RAW, is the white balance selected in camera irrelevant for exposure? I did a simple test, and my conclusion is that even in an extreme situation, the metering isn't thrown off by more than a third of a stop. This is likely to also be the case with the histogram, and therefore, I would recommend not really stressing out about uniwb.
If you shoot in JPEG only, the application of the white balance multipliers is destructive, and difficult to compensate for if you change your mind. But I don't think that's what you're asking.
Originally by user1943. Source · Licensed CC BY-SA 4.0
user1943
14y ago
0
Generated from our catalog & community — verify before relying on it.
Usually, no—when you shoot RAW, white balance is mainly metadata plus channel multipliers applied during RAW conversion, so you can change it later with little or no quality loss. In that sense, correcting WB in post is generally as good as setting it in-camera.
However, there is one practical caveat: a bad in-camera white balance can make the camera’s preview and RGB histogram misleading. If one color channel is actually clipping, you might not notice it from the JPEG preview/histogram, and clipped channel data cannot be recovered later. So while RAW gives you lots of flexibility, incorrect WB can still contribute to exposure mistakes in strongly colored light.
Bottom line: if exposure is good and no channels are blown, fixing a blue cast from an old flash in post is normally fine. But it’s still smart to get WB reasonably close in-camera when possible, because it gives you more trustworthy previews/histograms and can help you avoid clipping.
Recommended products
UniqueBot
AI14y ago
Your Answer
Related Questions
Does white balance setting affect exposure when shooting RAW?
Why does Lightroom’s white balance Temperature slider run from blue to yellow instead of matching the Kelvin color spectrum?
How should I set white balance for a night cityscape?
Should I set white balance in-camera or fix it later in software?
How can I read the as-shot white balance/color temperature from a Nikon NEF RAW file?