lens profile/correction in DT workflow
I have a fundamental problem concerning automatic lens correction.
Question: When should this be done within the workflow? … during import, after crop and lightness adjustments…?
What I did so far:
I have put it into the preset and the module shows up with right lens as step 13 in the (last) automatic part of the import workflow, but it is switched off ! If I put the cursor over the step 13 it shows substantial changes of the four lens parameters though, differing from original exif.
When I activate lens correction module manually, I see the module works correctly.
But it will eventually be switched off again after crop or lighting corrections
Lens fun db is activated, the lens type and brand is correctly detected
I’ve never seen a module switch off automatically.
What can happen is that a style switches off a module (has it included in that state).
For the rest, darktable has a fixed processing order (pixel pipe order) (*), independant of the order in which you activate or modify modules. So it doesn’t matter all that much when you activate the module, as far as the final output is concerned. But since lens correction moves pixels around, it might be more practical to activate it early in the process (so you see where e.g. a crop or a mask ends up).
(* : While you can change this pixel pipe order, that also has to be done explicitly: manually or through a style, those can only be applied manually).
Which parameters do you mean?
Tbh, I don’t see the usefulness of having a module like lens correction included in a style in the off state: I want to use the automatic settings if I use that module, so having it switched off in a style only adds a useless line in the history stack.
thanks rvietor,
attached you can see a screenshot.
On the left you see that the module 12 in stack is de-activated. On the right side the menu shows lens correction switched off. This is the status after import or stack-reset. Of course I can activate lens correction any time later again…
oh and the four parameters that changed referred to: distance, aperture, focus and scaling. can’t reproduce this at the moment because I deleted the preset and made a new one with only camera and lens make as parameters.
problem seems to be solved! I selected the correct lens again in the database, saved the preset. Now all works like charm. I assume the database changed sometimes since DT 4.4 - there are two versions of the same lense in the DB, and I selected the older one.
Anyway, I learned that I am doing right to correct distortions first in my workflow
Thanks again, thread can be closed
