Viewing the brightness RGB,

Software darktable
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Salute

Viewing the brightness.

Is there a view of the brightness of individual rgb channels, using the example of how it is done in RawTherapee, as well as the total brightness in b/w?

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You can use the Color Calibration module for individual RGB channels (or even their combination).
Note that it is an edit that is written to the history (so you can export it, I prefer this module for B&W edits), so it is not a view, technically.

You can also create a preset for each channnel to quickly switch between the views (I’d appreciate if anyone could explain me if white balance setting (CAT) would affect the results on different images, if it needs to be set to bypass)

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I tend to create a copy of the module when I use it for anything besides white balancing. And of course, that copy should have CAT set to bypass (or you apply two white balances, usually not good).

There is one exception: you can use the module in combination with masks to apply a different white balance to parts of an image, e.g. in situations of mixed lighting.

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Yes, I heard a tip here that self-luminous highlights in night photos look better when balanced to 6500K or something like that.

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I assume you want to check the values, and not the luminosity (for a given number n, red (n, 0, 0), green (0, n, 0) and blue (0, 0, n)) will not appear equally bright, green being the brightness, blue being the darkest).

Besides the channel-mixing approach (via the color calibration module), you can also check a channel’s values in the input or output of any module as follows:

  • temporarily enable parametric masks
  • by default, only the input sliders are shown, but you can enable the output ones, as well:
    image
  • hovere over a channel’s sliders and press C. Here are the input red and blue channels, for comparison (you can only show one at a time). To cancel, press C again, or remove the mouse pointer from the sliders:
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I think that ‘red’, ‘green’ and ‘blue’ are shown based on values in the working space, and are the input / output of the module, not the overall output of the pipeline.

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Thanks

It is a pity, of course, that there are no simple switches like RawTherapee, perhaps they will appear in the future, but for now we will go this way

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They may appear, if you ask for them. Please open a feature request on GitHub: Sign in to GitHub · GitHub (you’ll need an account).

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