I’m a new darktable user and I’m looking for advice when it comes to the correct usage of the colour calibration module. It’s really a very basic concepts question.
After reading the docs, watching tutorials and playing around, my understanding at this point is that the colour calibration module’s role is to create a stage in the pipeline where the picture is sort of neutral in the sense that whites and greys should appear as such, and not coloured by the light that was falling on them at the time of the shoot. Sort of like a reference point that should be set correctly so that other modules in later stages, like filmic and color balance rgb have a correct starting point to work as expected.
Is my understanding correct? If so, I’m having trouble understanding the following…
Suppose that I have a picture taken at golden hour. At the scene, there was a beautiful orange tint and I want to convey this to my photo. I don’t want to neutralize the effect of the sunset light in order to have accurate studio-like whites and greys.
In that case, how should I work with the colour calibration module? Should I neutralize the whites and greys and then try to bring back the golden hour colours in the colour balance rgb module? Or should I have an orange hue right in the calibration step. And if I do the latter, will this ruin the expected behavior of modules later in the pipeline?
I think there are different types of pictures. I mean, for many of my “everyday” photos I wouldn’t mind neutralizing them first. I mostly take the “As Shot” setting and live with it.
If we are talking about the genius picture, which you edit in depth, yeah… then I think you got the point. Create a neutral white balance with one or more color calibratrions and the colorize as you wish with the 4 ways in the color balance rgb. Thats for sure one way to handle things.
A fitting (hopefully ) video that comes to my mind is this one:
I would try to set daylight in color calibration an then match the exact color tone (gold) that I have in mind for the picture.
Just my 2 cents of course and I’m just an interested amateur.
I do the second option. Get the hue/tone/temperature I want in color calibration. I’ve never had a problem with other modules, but, I’m aware that it’s not the ‘scientifically correct’ approach.
You could in this case where you want to bias your results by the “look” just correct the cast with CC as normal… trying default or color pick on the whole image to remove the cast… then toggle the setting to custom…nothing will change but now slowly drop the chroma to reintroduce the cast to the level that you find visually pleasing…
So basically you do go neutral and then slowly remove that allowing as much as you want back into the photo…this lets you tweak it… The module authour would likely say make things neutral to be correct and then edit your look with rgb color balance but using custom in CC along with the other tabs in the module can also impart your look…
In the end its an exercise or perhaps the correct word might be objective of the model to best map the image so that it will appear as the scene illuminant when viewed to a given set of display conditions… and uses the full rgb data for the calculation instead so 3 scaling values used in traditional wb…
When I was trying to wrap my head around it I found this article explained things fairly well…
There are some interesting threads on the topic of the CC module that could be worth your reading.
For my use I have created a picture style which includes setting the CC module to as shot since much of the time I have good white balance straight out of the camera. Sometimes I select daylight to bring out the golden colors of the golden hour or the blue of the blue hour.
It is also possible to disable the CC module and just use the white balance module on its own. Sometimes I do this. I feel more comfortable with the traditional controls of WB module sometimes. Dare I say, but I feel sometimes the CC module makes a simple job difficult.
For me, the color calibration module (the illuminant correction part at least) is a (fancier) white balance module. So I respect the scene lighting just as much as I did with the “traditional” white balance module. If I do not like the “correct” correction, I just change it.
Not scientifically correct, but then, those are tools to create the images we want to create. Being able to exactly reproduce the scene is very useful. And there are situations where you need precisely that. But not always.
And no, using an “incorrect” correction here won’t ruin later modules. (in any case, you would see that…)
) video that comes to my mind is this one:
