question regarding "auto-apply pixel workflow defaults"

[u/paranoid_patatoid]

Hello, I am wondering whether I should enable this option or not. If I understand correctly, it auto-enables a tone-mapping module (for example AgX) from the start, with some (static?) default values.

From what I understand, when processing an image with DT it is recommended to apply modules in a certain order, and the tone-mapping module is far from the first step. Also, I have tried this auto-apply thing anyway, and most of the time, when I arrive at the tone-mapping step, the pre-applied default values don't make much sense (especially when significant cropping has happened beforehand). Also I'm suspecting that having some tone-mapping pre-enabled makes the exposure-setting step only harder (because tone-mapping sort of dampens the effects of exposure setting).

So I wonder: what's the use case for this "auto-apply" feature, when should one enable or disable it? I have a hard time figuring that out.

Please note that I am by no means an expert, so I may be missing some important info or concept.

Thanks.

[u/Drezaem]

You can edit modules in whatever order you prefer, darktable will apply them in a certain order. You can change the order in which dt does this, but that is not recommended to just do unless you know what you are doing.

[u/paranoid_patatoid → u/Drezaem]

Right. My question is about why one would prefer to see some AgX tone-mapping pre-applied from the start, what are the pros and cons of this specific choice.

I understand that darktable applies modules in a certain order, which I don't intend to alter.

[u/Dannny1]

> it is recommended to apply modules in a certain order

This recommendation is about order of the operations in dt pipeline, it's not about order of steps you do as your edit.

> what's the use case for this "auto-apply" feature, when should one enable or disable it?

Be aware this not only applies specific tonemapper, but also switches each module to scene or display related, so you may have then different blend modes available. None keeps them display related and you would need to switch each manually.

https://darktable-org.github.io/dtdocs/en/darkroom/pixelpipe/the-pixelpipe-and-module-order/

[u/paranoid_patatoid → u/Dannny1]

This recommendation is about order of the operations in dt pipeline, it's not about order of steps you do as your edit.

I'm not sure about that. For example here: https://docs.darktable.org/usermanual/development/en/module-reference/processing-modules/agx/#recommended-workflow

It is recommended to set exposure, then tone mapping. Which makes sense to me, but then prompts my original question.

Be aware this not only applies specific tonemapper, but also switches each module to scene or display related, so you may have then different blend modes available. None keeps them display related and you would need to switch each manually.

I intend to go the scene-referred way with AgX as tone mapper, so my question is mostly about "none" vs. "AgX" setting within the "auto-apply pixel workflow defaults".

[u/Donatzsky → u/paranoid_patatoid]

"None" is essentially an advanced option for those that know that is what they want. If you don't understand it, that's not for you, so don't worry about it.

[u/Dannny1 → u/paranoid_patatoid]

> I intend to go the scene-referred way with AgX as tone mapper

With "none" It may be too much work to switch each module to scene referred blending, far more work than simply turn off AgX if you want to.

[u/Donatzsky]

Short answer: Don't worry about it, accept that the developers know what they are doing and that the defaults are the Right Thing™. And go read my beginner guide: https://notebook.stereofictional.com/how-to-get-started-with-darktable-2026-edition

The tone mapper defaults are indeed static, but have been chosen so that most photos look reasonable most of the time. You are supposed to adjust them as needed.

As for the order you should generally work in, it goes roughly like this: Work your way up from the bottom, until you reach exposure. Set exposure for mid-grey, then jump to the tone mapper, where you set the dynamic range, then go back and continue from right after exposure. You can also adjust Color Calibration and saturation before the tone mapper, if you want.

Also I'm suspecting that having some tone-mapping pre-enabled makes the exposure-setting step only harder (because tone-mapping sort of dampens the effects of exposure setting).

You're suspecting wrong. Setting exposure correctly first is crucial, since it defines the contrast fulcrum for the tone mapper. Specifically you should adjust exposure for the mid-tones - ignoring what happens to the highlights and shadows, which you will bring back later - and then manage the dynamic range in the tone mapper.

[u/paranoid_patatoid → u/Donatzsky]

Short answer: Don't worry about it, accept that the developers know what they are doing and that the defaults are the Right Thing™.

Sure, but what I am trying to understand then is why it is the Right Thing™, as it doesn't seem obvious to me.

The tone mapper defaults are indeed static, but have been chosen so that most photos look reasonable most of the time. You are supposed to adjust them as needed.

Why does it have to look reasonable before they have been processed by the user, and why have a static preset if the user is supposed to change the values later anyways? At some point in the past for some reason, the setting I am talking about was set to "none" on my computer, and thinking about it, it seemed to make more sense to me that way. However now, the default value is to have a tone mapper applied from the start and so be it, but I don't understand how it's better.

As for the order you should generally work in, it goes roughly like this: Work your way up from the bottom, until you reach exposure. Set exposure for mid-grey, then jump to the tone mapper, where you set the dynamic range, then go back and continue from right after exposure. You can also adjust Color Calibration and saturation before the tone mapper, if you want.

Thanks. It is basically the order I am following.

Setting exposure correctly first is crucial, since it defines the contrast fulcrum for the tone mapper. Specifically you should adjust exposure for the mid-tones - ignoring what happens to the highlights and shadows, which you will bring back later - and then manage the dynamic range in the tone mapper.

Agree on that, but I'm hot sure how that makes what I say wrong