DN linearization problem

PiezoDN Digital Negatives
1

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)

Thanks

Alan

2

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

You have access to it at Piezography.com

Screen Shot 2021-02-01 at 9.36.08 AM
Screen Shot 2021-02-01 at 9.36.08 AM2376×1346 424 KB

regards,
Walker

3

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

4

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.

-Walker

5

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.

6

PPEv2 is for everything.

It does a stupendous job on negs.

best,
Walker

7

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

8
  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.

-Walker