From time to time I need to scan B&W film negatives. Lightroom (on its own) does not do negative-to-positive tonal conversions.
A great while back I learned a great trick to use ACR to create an "inverse tonality" curve (converting a neg to positive) to save & then use in Lightroom. Worked like a charm. The problem is, I think that was back in the days of Lightroom using Process Version 2 (or maybe 3?), and that trying to apply that curve in LR's current process version just doesn't work - no change to the image. (I can still use that curve if I drop back to the earlier Process Version, but of course that means losing some of the Develop tools of the current process)
I have tried to build a new inverse curve in the current ACR, but can't (the UI won't allow inverting the endpoints). Is there a way to construct a neg-to-pos curve that will work in the current LR Classic (without having to drop back to Process V2 or V3)? Or is this another example of Adobe moving on, assuming nobody needs or wants such a capability anymore?
Thanks for any thoughts...
John