White balance changes exposure?

Hello,

I just noticed that changing the whitebalance changes the exposure and by a lot. Is this normal? i thought with raw you could change the WB in post without affecting anything else.

Anyway, i compared Camera Raw an DXO, and the difference is huge., is this normal too? smart lighting was off.

Thanks

/J

What are the settings in Color Rendering? Are any other adjustments enabled? Can you show a comparison with different white balance settings in PL rather than in Camera Raw?

You’re set on manual, at least use the colour picker to set your white balance, or set it as shot before doing a comparison. Not really sure otherwise saying there’s a huge difference between….
Sorry it just doesn’t make sense.

You show a stage shot. I do a lot of that work.

The first thing I do to my RAW files is to correct the White Balance. It often makes a big change to the exposure. That does not worry me.

I then go on to do my other corrections and so often it still involves recovering burnt out highlights.

There is a lot of confusion about White Balance on RAW files. Unless the camera is doing something strange the WB setting on the camera will only be affecting its jpgs. But I don’t want this thread to become an argument about whether it does change the RAW file. You were interested in WB and exposure in DxO - and yes it will alter.

Tony

It’s also good to know that the colour temperature/tint sliders are of no calibrated scale. The same picture in various RAW converters and only used “standard settings” (whatever that is, it’s not the same in each converter), altering the temperature and tint sliders will lead to different results.

And as @TonyGamble said, brightness will alter in each converter differently.

Yes i am mainly interested in the exposure change when i change WB, i hadn’t realized that before.
and as i said when i boosted the WB it raised it so much which surprised me. Default import settings no changes. Best to set WB before even in raw i suppose, but for stage lighting i though to fix it in post :slight_smile:

Kattouf,

I usually have to photograph at the dress rehearsal stage and the lighting engineer is still experimenting.

The setting WB varies and I am constantly looking for white shirts and frocks - or some bit of the scenery. Whip through the whole sequence and sort the WB with the pipette. What you don’t want to do is correct the exposure and then tidy the WB as for sure it will mess up what you did!

T

white balance is at the RAW level a set of 3 multipliers (often just 2 in practise). The linear data from the RAW file needs is R and B channels multiplied to be ‘in line’.

Doing that through ‘temperature / tint’ is actually not that smart if you think about it, but people are used to it. But yes, RAW converters are calculating R/G/B multipliers (of which G often is just 1.0) to temperature / tint, and those calculations are not the same (for good reasons).

White balancing is one of the first steps in the entire RAW pipeline. If you pick a setting that boosts the R and B channels by a lot, it kinda makes sense for the exposure to change (since exposure is also just a multiplication of linear RAW data). Some software tries to normalize the exposure between WB changes, some others don’t.

Since the RAW data is then pretty quickly fed to an camera input profile, and somewhere down the line there is an exposure setting… and exposure affects how we perceive colors with our eyes (as in, dark blue can look quite different in the shadows vs brightly lit), this all isn’t as easy as you might think :slight_smile:.

Since every software handles color and ‘color science’ differently, how WB affects exposure and if that is wanted or not and how it affects the camera profile and the color reproduction… is all different software to software.

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As commented above, WB changes the relative multipliers of the R, G and B channels. And therefore affects the apparent exposure. It is very well possible that a scene that seemed to be overexposed has no blown out channel after WB correction, or vice versa.
Your stage scene appears to be flooded with relatively red light. This will be corrected after WB, and the area that you marked in your screenshot will get darker. If you do an automatic WB correction, it is very well possible that the result is different in PL than in other applications. Each one has it’s own recipe. The result will probably be more similar if you use the color picker in both applications.

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“It is very well possible that a scene that seemed to be overexposed has no blown out channel after WB correction, or vice versa.”

That is what I usually find. I get scared by the jpgs I’m seeing when I do my initial sorting (outside DxO).

A quick tidy up of the WB reassures me my exposure was not that way off!

Tony