Give user possibility to change white balance relatively
When I change e.g. temperature in white balance section, then save it as a new style and apply it to whole collection then every photo has exactly the same temperature set. It is not very practical solution.
My expectation is:
I change temperature from 4500K to 5000K (+500K). When I save this change as a style and set this style to the image that oryginally had 4700K (from RAW information) I suppose it to have 5200K as a result (+500K as well). This behavior could be optional (relative/absolute change option).
#1 Updated by Roman Lebedev about 2 years ago
- % Done changed from 0 to 20
- Status changed from New to Incomplete
Do note that we store white balance as multipliers.
The displayed Kelvin temperature is not representable (as in, across different software), and is only useful for information.
That being said, i i'm not entirely convinced that this could/should be done.
#2 Updated by Mariusz Jaskółka about 2 years ago
From user point of view:
Maybe this is my opinion but i think it is pointless to set the same white balance to all photos in collection. On the other hand it would be helpfull to make all photos warmer/colder approximetly by the same relative value (na matter which units is being used).
My use-case from today: all collection from the party in room with old-school bulb & all the photos was "too yellow" as my camera was working in auto-white-balance mode. I had to move "temperature" slider left about 500K manually for every single photo.
From programmer point of view:
I understand that temperature value could be calculated by darktable with it's own algorythm and is not compatible with other software. But is it really a problem? Moving slider left/right by the same value from what was read/calculated from RAW manually is possible so doing it automatically with preset/style is technically possible as well. How? One of the solutions could be to switch "white balance" filter between absolute/relative mode (similar to exposure filter's modes). But you are programmers/architects here :) ( I am too but I didn't read the source code ;) )
#7 Updated by François Tissandier 4 months ago
I agree that this is not the same as local white balance. And I find that also useful to be able to choose between an absolute white balance and a relative change to apply in a style (like -400K). Otherwise it's impossible to create a style which would, among other things, make the image less warm or more warm.