I miss the simplicity of adjusting white balance for artistic affect to make things warmer or cooler. Now that we’ve moved to the new workflow with the color calibration module, the default adjustment does a great job of removing any tint, but generally choses an adaptation which doesn’t allow colour temperature to be adjusted directly, instead offering a hue control. The overall improvements in processing make that change worthwhile, so I looked at options to have the best of both worlds.
I’ve found that adding a second instance of the color calibration module with adaptation set to black body and then adjusting the colour temperature gives good results, but also gives me a warning about double CAT applied.
What bad things may come from double CAT? What should I look for in my picture so I can spot any negative impact? Is there a better way to do this without having to guess hues? The manual mentions but doesn’t elaborate on:
These warnings are intended to prevent common and easy mistakes while using the automatic default presets in the module in a typical RAW editing workflow.
Because it doesn’t have a colour temperature control. I would have to identify the hue shift that I’m looking for and I find that a lot harder than simply making the image warmer or cooler.
I often use two instances of the CC module. I feel the warning is simply a warning in case you have accidently instigated two instances. If your method is working for you then just ignore the warning.
If you are going to use wb as a creative adjustment and not grade from scene neutral likely you might as well just set the CC module to daylight and you get the temp slider then dial the temperature and tint to suit your needs. You no longer need CAT neutral.
Go even further and just use wb…. The way I look at it you use the CAT to get a scene neutral from the detected illuminant of the scene…if you are going to do creative editing with wb then I imagine you are in a way by-passing this so my thoughts would be why wrestle with it….just go old school and use wb
it’s not something catastrophic - you might simply try to apply a white balance twice and wonder why it don’t work properly and then write issue reports in GitHub, or ask for help here …
If you know what you’re doing you can switch off those warnings in the preferences…
It’s similar to the colored steep sections in AgX, filmic or the warnings in tone equalizer:
If there are issues caused by the module - they might give an indication why those occurs, but if you can’t see unexpected stufff, then these warnings are completely irrelevant…
If this is the intention then it is not consistent with darktables overall philosphy of being able to go extreme and “break” things in almost every module. I think double tonemappers would deserve a similar warning. I regularily accidentaly paste settings between images and end up with e.g. sigmoid+agx active and sometimes not immediatly noticing it.
But: Nice. never noticed this setting! Thanks for pointing that out.
I’m really after any subtle issues that may be caused. Is there a hidden correction that undoes some of the work from the white balance module that may get double applied or anything like that? I’m not worried about catastrophic issues, I can see them. I’m worried about subtle issues that I may miss when processing a batch of photos quickly and then notice days later.
To rephrase: Darktable doesn’t hold your hand very much, many modules/settings are able to go extreme - which I like. I think the double-cat-warning doesn’t fit in there. But I’ll leave it at that :-).
just count the posts here or at github where newbies wonder why color calibration gives strange results
Thats something nearly each user coming from Lightroom etc. fails when trying to use darktable the used way assuming it’s just a Lightroom clone …
In my case I’m not coming from Lightroom and have been on darktable for a very long time. I’m perfectly happy using the current system for ordinary white balance. My questions are around creative use of the module.
If it looks good, it is good, but knowing what to look for helps.
