Some great info on this thread. I did a quick 2 point calibration a few months ago and am now trying to dial in a 10 point calibration with Calman and an i1pro2 with Videoforge on a firestick direct into HDMI.
After running with a 2 point calibration for a few months, this week I ran 10 points sweeps at BT.1886, dimming off, with the 940 gamma at 0, -1 and -2 and got the expected gammas of around 2.2, 2.3, and 2.4.
But my DeltaE error went UP when changing the Sony setting from 0 to -2 on the 10 point sweeps. If -2 approximates 2.4 at the low end I would have expected my error to be less at -2? It makes sense that BT.1886 would force different adjustments as you move from 0 to -2, I just expected -2 to be closer not 0. The gray scale stays pretty much the same as others have commented.
But if my understanding of BT.1886 is correct, whether you set the display at 0 or -2, BT.1886 will push you to RGB adjustments that make you end up in the same place from a gamma standpoint as long as you have the range. My tweaked 10 point DeltaE went way down but it pushed my gamma number down too and I prefer to be closer to 2.4 "look" than 2.2, fully understanding BT.1886 calcs differently. I could just leave my Delta E at 2 and really no change in the gamma, but if I pushed the Delta E down more, my gamma got lower (picture brighter). Of course some of this is theoretical with Delta E's under 3, although the gamma change was noticeable.
I need to run some more sweeps this weekend using a few different charts and spend some more time. Maybe even try some test patterns from a disc.
But just curious what others doing 10 point calibrations and BT.1886 saw with all the good experience on this thread. And also, are you starting your 10 point calibrations at 0, -1, or -2? I did read the whole thread but most of the discussion on gamma were on different matters although very helpful.
PS. Sorry for the lack of screenshots, used a different PC and did not run all tests! Also, if you choose to "reset" say "expert 1", it JUST resets those RGB settings, correct? Not the other ones?