I have a i1 Display Pro but no Calman Software. So I thought I would do the basics and adjust the rgb's atleast and then maybe more forward to grey scale.
First I installed DisplayCal on my HTPC (Archlinux) and started the calibration with the i1 Display Pro connected to the HTPC.
All I had to adjust was to lower the green level to get a perfect delta 0 according to DisplayCal.
I then made a desktop screenshot of the white test field that DisplayCal uses to calibrate.
I verified that it had the same color/values and would produce the same delta by opening the screenshot and moving the i1 Display Pro adapter over the "screenshoted" DisplayCal white test field.
I then connected the i1 Display Pro to my Windows Laptop which has HCFR installed.
Afterwards I opened HCFR and started the rgb monitoring while my i1 DisplayPro was on top of the screenshoted Displaycal white test field that was still shown on my TV via my HTPC.
HCFR now suddenly displays a delta of ~12.8 with blue being way to high and green being way too low.
What I basically did was:
Have my TV connected to my HTPC and display a white test field.
Adjust the TV rgb according to DisplayCal on my HTPC to a delta 0.
Still have my TV connected to my HTPC and display a white test field.
Adjust the TB rgb according to HCFR on my Windows laptop to notice weird different delta values.
The test image and HDMI port didnt change during the test.
Only the software for testing changed (and also the OS / Device because HCFR doesn't run on Linux).
Why do the two tools show such different RGB values?
Which tool should I trust?