Programs read White Balance differently?

[Thornton]

I was just playing around and found that two of the four raw converters I have which can process my Fuji X100 raws seem to give somewhat different interpretations of the camera white balance. Affinity Photo and PSE (Camera Raw, Standard setting) both agree on a temperature of 4900, the bundled Fuji (Silkypix) software reads the temperature as 4747, but DxO, which looks significantly different from the others, has a temperature of 5929. Something seems to be wrong somewhere. (I was going to post photos but don't seem able to upload to the website).

Julian

[Manfred M]

They do when you use the “auto” function. It’s a calculated value and depends on how the software measures and calculates the colour temperature.

That is why people shoot a gray card in portraiture and product photography.

[Thornton]

They do when you use the “auto” function. It’s a calculated value and depends on how the software measures and calculates the colour temperature.

That is why people shoot a gray card in portraiture and product photography.

Thanks Manfred. I'd assumed that the "camera" or "as shot" value was worked out by the camera and then that figure was simply read by the program.

Julian

[dje]

I was just playing around and found that two of the four raw converters I have which can process my Fuji X100 raws seem to give somewhat different interpretations of the camera white balance. Affinity Photo and PSE (Camera Raw, Standard setting) both agree on a temperature of 4900, the bundled Fuji (Silkypix) software reads the temperature as 4747, but DxO, which looks significantly different from the others, has a temperature of 5929. Something seems to be wrong somewhere. (I was going to post photos but don't seem able to upload to the website).

Julian

Yes Julian i have found the same thing. This is not surprising though because, as Manfred says, Color Temp used in the raw processing software is a calculated value and there are different ways of calculating it. The White Balance settings used by the camera are included in the raw file as simple multipliers for the R and B channels, not as a color temp. When applied to the image, the multipliers make all three channels (R G & B) equal for a neutral grey subject.

For raw processing purposes, it is much more convenient to use color temp as the user interface rather than these multiplier values. Adobe uses a fairly complex method involving a camera color matrix and profiles for two different illuminants (where possible) to convert the multipliers into col temp (and tint). Other raw converters use one or two other methods (for which i have seen very little detail).

Dave

[DanK]

Thanks Manfred. I'd assumed that the "camera" or "as shot" value was worked out by the camera and then that figure was simply read by the program.

Julian

That's my interpretation as well. I use only one (or two, depending on whether you count ACR and Lightroom as different) raw converter, but in that case, I believe "as shot" is a reading of the image as it was taken, before the value after alteration, whether by an auto adjustment or a manual adjustment.

I had always assumed that this was simply read from EXIF, but if that were the case, all of the programs would give the same as shot value. I wonder if the DxO is after an automatic adjustment.

[Thornton]

That's my interpretation as well. I use only one (or two, depending on whether you count ACR and Lightroom as different) raw converter, but in that case, I believe "as shot" is a reading of the image as it was taken, before the value after alteration, whether by an auto adjustment or a manual adjustment.

I had always assumed that this was simply read from EXIF, but if that were the case, all of the programs would give the same as shot value. I wonder if the DxO is after an automatic adjustment.

What I have found is that the “camera” value of 4747 given by Silkypix (Fuji) when using the “Default” parameter set changes to a “camera” value of about 6000 when the parameter set is changed to “Super Neutral”.
I certainly think with this particular shot I was processing, that the DxO colour looks more pleasing than the others.

[pschlute]

I'd assumed that the "camera" or "as shot" value was worked out by the camera and then that figure was simply read by the program.

Every raw converter can treat white balance differently. Most will have a setting that reads the "camera setting" and you can use that if you wish. But that is subject to the vagaries of what "jpeg" setting you have set on your camera. A raw converter will also have an auto setting which may or may not get close to your intentions. My converter of choice has about 12 others plus the infinitely variable temp sliders. As Manfred says, if you want consistency use a grey card.

The whole point of using raw is that your white balance is not baked in, and can be changed at will. If you want more accuracy than eyeballing the raw file in pp, then shoot the grey card and sample it in post.

[DanK]

What I have found is that the “camera” value of 4747 given by Silkypix (Fuji) when using the “Default” parameter set changes to a “camera” value of about 6000 when the parameter set is changed to “Super Neutral”.

There is at least part of your answer. The "camera" value in that program must not be neutral but must instead reflect whatever picture style (or whatever Fuji calls them) you choose. A picture style is a set of postprocessing steps that creates a given style of JPEG if you shoot JPEG. Different picture styles impose different color balances, saturation levels, etc., so it is not surprising that their white balance settings are different.

In the case of Lightroom, the "as shot" value is not affected by the rendering profile. I just tested this by taking one raw file and using several different profiles to render a starting point, including both Adobe's own and their emulation of one of the Canon picture styles. The "as shot" value did not change at all.

[dje]

In the case of Lightroom, the "as shot" value is not affected by the rendering profile. I just tested this by taking one raw file and using several different profiles to render a starting point, including both Adobe's own and their emulation of one of the Canon picture styles. The "as shot" value did not change at all.

And that's what you would expect. White balance is quite separate to color rendering with a camera profile. Profiles are designed to be used with white balanced raw data from the camera so white balance has to be applied before color rendering.

If Silkypixs works differently, I'd say it's the odd man out! I've never used it.

Generally speaking, white balance should be separate from picture style etc in camera. After all, WB is a separate camera setting.

Dave

[dje]

The whole point of using raw is that your white balance is not baked in, and can be changed at will. If you want more accuracy than eyeballing the raw file in pp, then shoot the grey card and sample it in post.

White balance adjustment can still be done on a jpeg or tiff. It's just that the original color temp information is gone. You'll find the CT and Tint set to zero and the adjustment is relative to this. Not ideal!

Dave