Created attachment 181549 [details] Results of Steps to Reproduce SUMMARY STEPS TO REPRODUCE 1. Set up tablet (physical hookup, launch driver, etc) 2. Open krita 3. Select a brush with opacity controlled by pen pressure (i.e. Basic-2 Opacity) 4. Paint with the brush at full pressure OBSERVED RESULT The brush stroke never reaches full black. It caps out at ~50% gray at full pen pressure EXPECTED RESULT The opacity of the stroke should be fully opaque at full pen pressure SOFTWARE/OS VERSIONS Linux/KDE Plasma: Ubuntu 20.04.6 LTS Krita Version: 5.2.9 (installed via snap) XP-Pen Driver Version: 4.0.7 (7c4a501) ADDITIONAL INFORMATION The Artist 16 is listed as "supposed to work" on the [List of Supported Tablets](https://docs.krita.org/en/reference_manual/list_supported_tablets.html#list-supported-tablets) Tablet has 8191 levels of pressure sensitivity I opened `Settings > Configure Krita > Tablet Settings > Open Tablet Tester` and was able to see that the pressure input was getting clipped at 47.4% (pressure level 3882)
Created attachment 181550 [details] View of Tablet Tester Output. Shows pressure maxing out at 47.4%
Created attachment 181551 [details] Work around that I have found I can work around this bug by adjusting the global input curve, but it cuts my pressure range in half
Created attachment 181590 [details] driver output is correct I used `evtest` to check the raw output of the driver and it is reporting values just fine. It is reaching its max value of 8191 (not clipping at ~3882). This indicates that the issue is likely how krita is ingesting this information.
Documentation says that the tablet tester doesn't modify the value at all. Given that the driver is outputting the correct value and krita isn't modifying it, I believe this is a QT event issue https://docs.krita.org/en/reference_manual/preferences/tablet_settings.html
I have cross posted this issue with QT: https://bugreports.qt.io/browse/QTBUG-137091?filter=-2 I will wait to close this bug until someone from the krita development team chimes in