Introducing color calibration module (formerly known as channel mixer rgb)

Software darktable
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Thank aureliene. Thank you a lot for your time and efforts for trying to make us understand these concepts. Not all developers (few of them, indeed) take such an effort.

I think i more or less understand what you mean, and as often i am sure you are right.

I don’t meant temperature and tint is the correct model.

I meant they are concepts people have managed to ‘u dertand’ even no in depth or being a not completly correct model.

But literature and tutorials have simpkified this concepts enough in a way that comon users can manage them.

I undertand more or less what is temperature as the temperature of a black bpdy that radiates a given light wave seen as a precise color.

But tint us not as easily understood. Many colors are not possibleusing just a radiation body.
So tint is a kind of deviation from the locus? Of the radiatong body, something like the distanxe from the nearest color that can be emited with it.

I don’t know if that is exactly what tint is, but i think it is a working model for not technically people.

It seems quite an artificial model, by the way.

I would be glad to change it for another one. You say chroma and hue.

But we will need a better understanding of what chroma and hue is.

I have seen previous links to very good books and online tutorials.
But reading almost 300 pages would be a bit hard to begin with.

I will try to read them slowly and see if i can understand part of them and improve my knowledge.

Meanwhile i would need a working definition of what chroma and hue is.
I have read this terms in many places but used in a loose way.

I had thought hue and chroma were similar, but it is obious they are not.

I have read dtdoc about color concepts, but not fully understood what hue and chroma is, will need to find more examples about it. And read it slowly and in a big screen and not in mobile to see if I can understand it.

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Just replace invalid with see manual :slight_smile:

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It’s not darktables purpose to widen audience; main purpose is to widen capabilities useful for those that are limited by simplified tools

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I’m going to chime in here and say that darktable is too powerful to not expect people to read the manual.

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The manual is useless when it gets too technical for most peopke, but the ones who understand the color science.

I can understand what hue is, everybody has used the color wheel.

Chroma is not as easy to understand.

I love aureliene explanations about color concepts, anyway.

I have to read it more carefully to see uf i can understand it, but some .ore graphucs with the color wheel and may be some graphic about what chroma is may help.

Results are great, we just need get used to the interface and new concepts.

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The manual tries to keep everything straight in constant terminology without making it hermetic.

If you don’t understand chroma or hue or both there’s https://darktable-org.github.io/dtdocs/special-topics/color-management/color-dimensions/ :slight_smile: specifically made to explain terms used.

see https://darktable-org.github.io/dtdocs/special-topics/color-management/color-dimensions/#illustrations :stuck_out_tongue:

As you can see - the manual is SUPERB.

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I would agree, the manual is great and I use it almost daily.
But I can see why some parts are not always easy to understand for some. This is partially because some of the concepts are inherently hard to understand. But I have also noticed some terminology from the world of mathematics and physics used, which can further cloud comprehension for those without this kind of background. I’m not sure if the manual still includes such words, but two that come to mind are “orthogonal” and “abscissa”. Layman’s terms for these would be something like “at right angles” and “x axis” respectively. The manual’s attempts at being very precise and technically accurate are one of its many strengths, but keeping it in plain English as much as possible should be a goal in my opinion.

I’m an editor by trade and have previously offered to contribute to the manual if more volunteers are needed…

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http://www.huevaluechroma.com/ This is a great site with some nice explanations and examples…

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contribute as much as you can :slight_smile: Including huevaluechroma stuff.

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Thank you all.
I have read it but not fully understood it.

Hue i think i understand it, it us the classuxal color wheel.

Chroma has a definition that is not all that simpke… What do we understand for colorfullness compare to gray?

It is not so simple to understand
I thonk of it as some kind if aaturation, but not in the perceptive world but in physucal world.
O us gray 100% full color corresponding to hue.

I have to study the graphs, but in the mobile i cannot see the well, will havd to wait for a pc screen.

The explanation about saturation and chrima sounds very inyeresting.

The link would help too, thank you.

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Will do, thanks!

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Agreed. You don’t need an invitation. All pull requests to dtdocs are considered. If you want to make major changes, best to raise an issue for discussion first though.

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I doubt I would be making any major changes; more likely changes of a proofreading/editing nature for consistency/clarity.

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I have read manual and the provided link. Thank you, I think i have a better undertanding of chroma, hue and other concepts.

Manual explains perfectly what invalid means in color calibration module and that it does not invalidate color correction, just that the used illuminant does not fit plankian model.

I have sime doubts about chrome, may ve i have misunderstood it.

But in the link and concepts definition in manual talks about chroma as a perceptive property: how close or distant are we from a gray with the same lightness as seen by a human observer, so perceptually as we see it with our eyes and brain.

But in many of the recent modules talk about chroma as scene referred, thus physical or at least phisiologically, after using cone filters in our eyes.

May you explain this a bit more?

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VñBy the way, may be i can help in translating parts of the manual to spanish.

Is there a way of doing it without installing git and hugo?
Some kind of online page were you can paste the translation?

Right now i am not easy accesd to my computer, after summer i will get more involved.

We have a spanish speaker forum about dt that can help in polishing my translation, or privide more translators.

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Please see here for details. All translations are done online in weblate so you don’t need to use git/hugo at all. Edit: looks like Spanish is currently at 100% translated, though weblate is not currently entirely up-to-date with the English version of the manual. We’ll look to get that updated within the next few days.

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Yes, it’s translated even so fresh eyes could be great.

@ariznaf I encourage you to work in the translations :slight_smile:

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Sometime all the explaining the world may not resolve the issue…If you pull up a color wheel esp one that has also a saturation gradient and use extreme slider adjustments you can visually see what it does to primary and secondary colors…then you can apply the observed behaviour to your images.

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Thank you for the info.

I will try to help with translations when needed.

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Definitely true. Some concepts I have read over and over again and I still don’t fully grasp them. At some point you just have to move on and use your eyes to see what you like. It can be frustrating though, I do sympathize with others who have trouble comprehending some very abstract ideas. We all have different strengths and what’s intuitive to some will never be for others…

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