Time to make the rail stop. Can anyone confirm my findings?

Sigma 8mm f/3.5 DG for Nikon
4 shots around
Tilt angle----------NPP value

+7.5¬?---------------0.15
+5¬?------------------0.5
0¬?--------------------1.2


Sigma 8mm f/3.5 DG for Canon
4 shots around
Tilt angle----------NPP value
+7.5¬?---------------1.65
+5¬?------------------1.95
0¬?--------------------2.65

Let me know if you find any discrepency.


Nick