DN linearization problem

I keep getting the message "Invalid linearize curve – not constantly increasing” while trying to do a DN calibration. I haven’t had to calibrate for a while and haven’t had this problem before.

Attached are the measurement file and the cgats file:

P800-PiezoDN-New-Cyan-lin.txt (2.5 KB)

P800-PiezoDN-New-Cyan-lin.txt (4.7 KB)



I think you need PPEv2 for better control and to get around the droplet bugs,.

You have access to it at Piezography.com


This for a digital negative. Don’t I have to use 129STEP_PIEZODN_CGATS_SMOOTHER to do the linearization? I already have PPEv2.

yeah, you can put those smoothed measurements into PPEv2 and bring your smoothing to like only 10% or so, pop the starting curve in, and the lin’d curve will be in the New Curve sheet.


But isn’t ppev2 for positives? Won’t the linearization work on opposite ends of the tonal range for a PiezoDN negative? If not, why does the manual say to use the 129step smoother for PiezoDN negative? The measurement curve looks the same in both spreadsheets.

PPEv2 is for everything.

It does a stupendous job on negs.


IF that’s true, why is there a separate section in the Piezography manual for PiezoDN and digital negatives that uses different excel worksheets?

  1. PiezoDN came out before Piezography Professional
  2. PiezoDN is cheaper. It is now an “alternative” to PPEv2 for calibrating negs IMO but we are keeping it as a starting workflow for those getting into PiezoDN for the first time.