If we take ‘filmic rgb’ as the pivot point between scene-referred and display-referred (I’ll ignore base curve as we’ll consider it depracated, though base curve has moved quite a bit in the pixelpipe), a lot of modules have moved from one to the other between darktable 2.6 and darktable 3.0 (i.e. between an image previously edited in darktable 2.6 and an image that’s newly-imported into 3.0).
Moved from scene-referred to display-referred:
- color reconstruction
- vibrance
- colorize
- color mapping
- bloom
- shadows/highlights
- local contrast
- color zones
- lowlight vision
- monochrome
Moved from display-referred to scene-referred
- rgb levels
- rgb curve
- sharpen
- lowpass
- highpass
- lut 3d
- channel mixer
I can’t disagree with any of these movements in general – they look like positive changes. But many of these modules will have very different effects in a 2.6.x-edited raw than in a 3.0-edited raw.
This means that you can’t come up with a workflow using the 3.0 modules and then apply the same workflow to a file previously imported via 2.6.x, with consistent results (even if the only thing you enabled in 2.6 was, for example, the crop & rotate module). The very fact that it was previously edited in 2.6 significantly changes the pixelpipe order.
I think we should recommend that users wanting to move to a new (3.0-based) workflow start from a fresh edit, i.e. discard their prior history, first. Those wanting to retain a crop should do so by duplicating, discarding and pasting as I’ve described above.