Hi Brandito, thanks for your good words.
By experience with my 37LG30, I've learn that because of the Display LT probe precision limitations when measuring gray levels luminance and chromacities below 30% gray level and the limitations of an LCD TV to display very dark blacks, I calculate and set my optimal 2.22 gamma at a gray level of 40% or 30%, which roughly correspond to 13.1% or 6.9% respectively of the peak luminance output at
100 % gray level (which should be between 30 and 60 ftl).
That way, I usually get a proper 2.22 gamma in the range of 40% at 70% gray level (which covers the "usual" range of movies and TV programs), even if the gamma in the range of 0% to 30% is a little bit lower and the range of 80% and up is a bit higher than 2.22.
Also, I discovered than when the "Black Level" is set to "High", the 10-points IRE calibration method settings are messed-up, in the sense that the 100 IRE setting affects a pattern of 109% gray (254 value), the 90 IRE setting affects a pattern of 100% gray (235 value) and so on.
I have done a first calibration run with DVE blu-ray using the color filters, so the settings I have found for color may not be accurate nor optimal. After the 100 hours break-in period I will test the settings again with my Display LT. Usually, I let the color control at 50 and adjust the CMS controls for each color individually.
you're absolutely right about the 40-70% gray levels though. they fall right into the 2.2 gama range pretty easily, the 30 and below are generally a bit lower in gamma, dipping to around 1.9 and the 70 and up get a little low in gamma. i've found it's just a limitation of the tv i guess. still looks much improved.
just redid my colors, went with a 52 setting for color and adjusted the cms controls from there, i based my secondaries off my primaries as this seems to be the suggested course of action. i've been using the accupel calculator to find all my measurements for secondaries and luminance for my cms and greyscale.
and yes, i too noticed that the 10 point ire settings are off when calibrating with a high black level, though i never gave much attention to the low black level.
even though they are off you can still fine tune it a lot more than the 2 point, in fact i think it's almost better they're off since it does allow you to adjust the 105% and 109% white using the 100 ire
you do have to do a lot of back and fourth though. you adjust the 50 ire for the 60% gray and also need to do a little adjusting of the 60. i started making my adjustments using the 100% white, get it to around 29 ftl or 100 Y value, higher and it's really difficult to get the gamma right. then i worked my way down. the 90 ire has no bearing on the 90% gray, same with 80 ire on 80% and down to about 70, below that and you have to kind of go back and fourth adjusting the level you're on and the one below ie for 60% you adjust 50 and 60 ire levels.
as i went along down i would get the level i was on correct with one ire lower (70% i adjusted 60 ire) then when i'd go down a notch i'd see what i could steal for that level from the same ire. so i would get my 70% right using the 60 ire, then check 60% and skip back and fourth between the 60% and 70% patterns to steal what i could in the 60 ire level for the 60% pattern without affecting the 70% pattern. then i'd go down and ire level and fine tune it. this obviously work down to about 30%. the 10-20% are very difficult because the way the 10 point ire settings are off. basically i did whatever i could to get both colors as close as possible, ignoring the luminance for the most part on those levels.
i dunno how clear i made that, just hoping i could save you some time when you get to do your set. sounds like you've had more experience than me overall though so i doubt you'll get stumped.
btw if you haven't already i suggest checking out the accupel calculator, saves time when trying to get your gamma right, gives you the Y values for each gray level based on your 100% white Y value. then you just need to adjust the green down to about the right Y value and fine tune from there.
looking forward to your results. no one else with this tv has really been overly vocal about their calibrations.
final expert 1 22 gamma.zip 4.294921875k . file