Editing moments with darktable

If you aren’t using one already, I’d highly recommend shooting with a circular polarizer. I’ve found it makes an incredible difference in making the sky blue and enhancing the contrast between blues and clouds. See an example here of the difference it can make

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To my taste, there is too much yellow in the green. It no longer looks as fresh and spring-like.
Here is a version with a reduced yellow tone for comparison:

Overall, I think both photos have a yellow cast which reduces the separation between warm and cold colors.
In the second photo, the rough local contrasts make the texture of the green areas very busy.

In general, with the pastel look - because the global contrasts are reduced - you have to make sure that the separation of subject and background is achieved through color separation (among other things, by reducing the color range) and good weighting of local contrasts. This is no easy task. And not all motifs are suitable for this type of look. You have to try it out.

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New episode: rgb primaries module:

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Fabulous stuff Boris. I liked particularly how you demonstrated the speed at which corrections can be made. What is your principle for choosing which slider to adjust? It seems there might be several options. You used the green here to remove yellow, for instance. I guess it’s mostly obvious but not always, to me at least. I realise you covered this in past videos with the channel mixer. Thanks again for this inspiring work.

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Thank you! Which slider to use depends on which colors - apart from the ones you want to change - also play a role. For example, in the photo with the woman with the green background, I wanted to reduce the yellow in the skin tone and also the yellow from the green leaves in the background. The hue shift from the green primary color towards cyan was decisive for this, although I could have achieved the reduction of yellow from the skin by shifting the hue from the red primary color towards magenta.

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Yep. I think it’s quite intuitive when I use the sliders. Interesting to hear the reasoning for using one option over another. Thanks

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Thanks Boris, The clarity you brought out is beneficial. I also gathered that Color Calibration and RGB Primaries are complementary, you can use one or the other. The RGB primaries is just a more elegant and intuitive way of achieving the result. Is this a fair assessment?

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Yes, but I see the rgb primaries as a simplified and reduced version of channel mixer. For example, the manipulation of primary colors is limited to protect the white point and you have an extra set of sliders for color toning. This is very good for making some quick and easy corrections.

Channel Mixer has no limitations and accordingly offers a much wider range of creative implementation. However, it is not as intuitive and easy to use.

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Great tutorial as always! I was curious if you ever use color calibration or rgb primaries with masks? I can’t recall seeing this done in any earlier videos.

I’ve tried pairing rgb primaries with a parametric mask to target highlights or shadows, but I’m not sure if I’m over-complicating things.

Sometimes yes, but very rarely. The photo must have very difficult light/color conditions that cannot otherwise be handled. Why should you treat highlights and shadows separately?

I remember AP in one of his videos pointed to the shadows, contrary to highlights, not being lit by the sun, but rather by the (blue) sky and/or reflections from colored foliage, buildings etc .

I see.

However, it is rarely the case that you actually have to treat it that way, because in my understanding this is part of the natural lighting.

A typical example would be photos with a snowy landscape where the snow illuminated by the sun has a warmer color than the shadows, which get their color from the blue sky. For me, this is part of natural lighting and does not need to be corrected.

Where I see more sense is when you have two light sources with different colors where you don’t want that, for example in portrait photography so that the shadow side of the face has a different color than the illuminated side and you want to balance that.

I have rarely had such situations where masking was necessary.

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I have always felt there is a great power hidden within the RGB Primaries, though I couldn’t exactly tell why and I used it by trial and error.

Now, thanks to your video I see one huge thing (to me at least): protecting the greys.

Eliminating such colour casts as those from yellow umbrellas is just outstanding! I think it looks better than just targeting particular colours in Colour Equalizer and / or Colour Balance RGB, because all the pixels in the image are more or less affected, the shifts are gradual and smooth, as a result (and somewhat automatically) the contrasts are better pronounced and we don’t need to worry about masking or artifacts of not good enough masks.

Multiple times I chose “the lesser evil” eyeballing the white balance, simply because if I picked the WB even from something like Spyder Cube or Colour Checker, besides white and greys, everything else looked way off.

Now the only thing I need to do, is to get familiar with achieving secondary colours to counter the casts. Hence my new wallpaper is:

:wink:

And I think we can create a little handbook with common problems and solutions, something like

If after whitebalancing with Colour Calibration you see:

  1. yellow cast in the skin
  • move the green slider to the right (towards cyan)
  • and the red slider to the left (towards magenta)
  1. skin too reddish
  • move the green slider to the left
  • and the red slider to the right (both towards yellow)
  1. the skies should look similar to Fujifilm’s Classic Chrome
  • move the blue and the red sliders to the left

The list is open to new entries :wink:

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That is indeed a very good decision. Perhaps even the most important one when it comes to dealing with colors.
I find it astonishing that the knowledge of color mixing in photography is only such a marginal element and hardly gets any attention. When you learn to paint, this is one of the basic skills you need to master. In my opinion, this should also be the case with photo editing.

A very good idea. However, I would supplement it with an explanation of what happens in terms of color mixing using an example. This avoids the typical blind following without understanding.

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Hello,
Great tutorial!
I’ve made a post 2 years ago about RGB Primary Corrections with Abstract Profile under RT.

It makes the same job you described in the middle of your new episode.

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It guess it’s possible to set up presets with the proviso that they’re just a starting point. I have a couple in color calibration/channel mixer, say, for boosting the red/yellows and cutting blue in foliage, or darkening skies. Be nice to have something shareable, somehow.

Talking of which, @s7habo I noticed some interesting looking tone equaliser presets in your latest video. Would it be possible to have a closer look at those or even share them to the community who might be interested? I tend to default to the same tweaks so interesting to see alternatives that I would never have considered.

Thanks

P.S. I have had an rgb Venn diagram as my desktop since Boris started posting his channel mixer videos.

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The only one I often use is what I call “linear shadow brightening” and it looks like this:

grafik

I know mathematically you’re not supposed to do it that way but rather use an “s” curve, but I don’t care because it works very well.
I have two versions of it, one with EGIF and one with guided filter.

Mask exposure compensation can serve well as a kind of fulcrum for brightening.

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Thanks!

Oh! I love the “linear shadow brightening”! Here is my first try with it, and I like it much better than my previous edit.


24-05-25__MG_0703_01.CR2.xmp (8.9 KB)

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I have an exposure preset to sort of do a similar thing. I use a luminosity mask of sorts made by dragging the main highlight boundary slider all the way to the left. I leave it feathered 100 percent. I blend this in addition mode. It’s a sort of shadow biased lift. It can work really nicely on some images…

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