Originally Posted by njfoses
I went and used the same settings and used the apl patterns this time and the results vary by a good amount. Using the apl patterns for grayscale my grayscale is much to blue.
I don't know why xy measurements would be any different unless the meter is picking up another part of the pattern like discussed in the thread from SOWK. The discussion there was that maybe the meter was reading the black along with the center measurement area. On my TV the xy measurements don't change much, even with the color APL patterns and how my TV doesn't have a great ANSI contrast compared to other technologies. Anyway I would have to see your measurements and get more of an idea about the i1 setup to really take a guess on this one. For xy you can really just use typical patterns, because the APL patterns basically have to do with Y measurements.
My brightness, contrast and gamma all changed using these patterns as well.
Generally all the Y levels would be expected to change.
Now im confused for grayscale, brightness, and gamma im not sure which is correct?
You cannot measure on-screen gamma with an adjusting iris using typical window or field patterns. The numbers it will give you are nonsense because the light output (Y) will change depending on the pattern. The idea with the APL patterns is just to try to keep APL from changing to try to measure on-screen relative levels.
Gamma is just about relative light levels. If your display adjusts light levels depending on APL, then the APL pattern should give a better idea about on-screen gamma. Of course the on-screen relative light levels may also change depending on APL, so that's why there are two sets of APL patterns in those sections. The first large patterns are to look at a somewhat high APL, and the small ones are to look at a low APL response.
Anyway if you don't get what I said above it's no biggie. Just don't look at gamma with typical windows or fields on a display that varies light levels, and don't set your color based on Y measurements if the levels vary depending on APL. Gamma and setting color are the two areas where adjusting light levels become a problem. Both of those situations have to do with relative Y levels, so if APL causes Y to vary then the results are really not as intended when using typical window or field patterns.