Styles and the "raw black/white point" module

I was having trouble with magenta highlights earlier and unusually, I had exposed using iso 160 on my eos 6D. I eventually noticed the raw white point was at 15,100 (or thereabouts) which is too high for iso 160. It’s ok for iso 100 on a 6D, which is what I often use. It seems this happened because I had the black/white point module in my Style, set at 15,100.

Initially I thought what a fool having that in my style, but it’s an easy mistake to make - of course you must have this module working with any raw file. But it’s reasonable to assume it will carry on adjusting according to ISO, surely? This adjustment is not like increasing saturation, say, which is a matter of taste; it’s a technical parameter which has got to be set correctly.

Enhancement? - I think dt should warn you if you try to include this module in a style. I wonder how many others have been caught like this.

Well, modules in styles are added to what is already in place, and identical module earlier in the history are overridden, just like when you add the modules by hand.

Now, the dilemma is what to do with automatically added modules with auto-selected values: in some cases, you want to keep the auto values, in others you want to override the automatic values (e.g. because they are wrong for certain cases, or you don’t like the automatic values)…

Also, IMO styles should contain the minimum number of modules needed to get the effect you want. Reason: if there are extraneous modules, applying multiple styles can have unexpected and unwanted side effects, because they override earlier applied modules.

So, while a warning when you include automatically applied modules in a style could be useful, it’s also a bit patronising, in that you don’t trust the user to know what he wants.

@rvietor, where you say modules with “auto-selected values”, I think you mean modules which are driven by factors which change from one image to the next, like ISO (in the case of whitepoint), or lens model (in the case of aberration correction). This is in contrast to modules which are driven only by user-supplied values, e.g. saturation = 120.

I think it would be good if dt could at least warn when one of the former types of modules is involved in a style. I suppose this could be when you create or amend the style; or at the point of applying it.

Note that it’s very easy to end up with whitepoint in your style. dt invites you to create a style from the history stack.

I don’t think this is patronising! For one thing, some users will not be aware of this pitfall. And there are already possibly “patronising” messages like when you output having explicitly set the override setting on - it still warns you might be overwriting every time.

Well, when I start making a style from a history stack, most modules are not selected. Notably, none of the automatically included modules is selected for inclusion, even when I changed the settings of some of those modules. So e.g. inclusion of the raw black/white point would be my explicit choice…

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@rvietor, it doesn’t work like that for me on the Feature Release of 9 March, “3.0.1 + dirty”. What version are you referring to please?

3.0.2, the latest stable version.

In that version at least, it is possible to modify existing styles from the “styles” section in the right sidebar of lighttable mode. That means you can remove (and add) modules from/to the current style.

(Note that I prefer using stable versions, as development/feature versions can have unexpcted behaviour, which is less likely in versions tagged as stable)

@rvietor, I will build 3.0.2 soon and have a look.
Where do you look to see the status of a release, e.g. stability? In this forum, 3.0.1 and 2 were both announced as feature releases using the same template.

Please try simply pressing “save” when you get that window with all the modules not selected. In 3.0.1 this creates the style with all the modules active!

Have now tried 3.0.2; same as .1 re. this issue.

To recap: I am suggesting it is bad to have the black and white point module in Styles, and that dt makes it easy to have this problem. @rvietor, you suggested this only happens when the user deliberately does it.

Having just tried 3.0.2, it is still easy to have this problem, same as 3.0.1. This is what I am doing to demo this -

  1. Import a new raw and go into darktable.
  2. Click the “create style” button and see this pop up -
  3. Enter a name and click save.
  4. Go to lighttable and see the style has been created. Select it and click edit. See this -

Firstly then, I didn’t explicitly choose black/whitepoint, but it is there and active, ready to trip me up when a different ISO comes along.

Secondly, I didn’t actually choose anything! That is surely a bug, all the “include” checkboxes in the first window should be ticked.

So to re-iterate, I think there should at least be warnings when this module is included in a Style.

Maybe for now just rename the module if you make a change to it so if you see it in the style it will flag your memory…

Now I’m aware of the problem I’ll ensure that module doesn’t get in my styles.