Originally Posted by cgh015
my 75% APL readings
If you haven't done so already, I would probably switch to the "HDTV - REC 709" reference (see step 1.5 from the guide). When you are at the main screen (measures tab), look to the left of the sensors area and you should see a couple arrows. If you click the down arrow to the right of the "Editable data" text a few times you should uncover a "delta luma" line. The delta luma line compares your relative Y measures against the reference.
The delta luma line says that your blue lightness (brightness) is dead on, which is about what I would have expected from a blue mode. The delta luma line says that brightness for green is also very good. The delta luma line reports red as too bright in comparison to white. If your TV has CMS type of color controls you may be able to reduce red lightness to bring it more in line with the reference. Personally I would probably see if there's a way to get red luma to measure closer to zero, but that's about it.
If you view the CIE diagram your measures don't line up perfectly with Rec 709, but they're not bad. Green and red are inside the reference triangle (undersaturated), yet the hue (angle) of red and green are good. This might just be how either the TV or meter performs. If you haven't already made changes that moved red and green in toward white, or if the TV doesn't offer a setting with wider primaries, there probably isn't a way to move red and green xy position closer to the reference. Maybe blue could be rotated (blue hue adjustment) a bit counter clockwise, but really blue is about as close to reference as can be expected. I'm not familiar with the TV or exactly what color controls Samsung includes, but generally I thought the CIE diagram was very reasonable.
should i be using the 75% or 100% modes for calibrating? because I thought it said to use the 100%?
I'm not sure what you mean by modes. I'll assume you meant 75% or 100% color patterns. On these patterns the percentage is usually shorthand to mean percent stimulus. Really the 75% Colors could be said to be 75% Stimulus Colors. The reason I suggested using 75% stimulus colors is because color bars for use with a blue mode usually also have 75% stimulus colors. Anyway, my main point is that using 75% is perfectly fine, and generally that's what I look at first.
Personally I think the "Terminology" and "Adjusting Color using a Color Management System (CMS)" sections from https://www.avsforum.com/avs-vb/showthread.php?t=852536
would be useful to understand if you are going to be adjusting a CMS. I'm sure it took me a while to understand what he's saying there, so at minimum it would probably take multiple reads. Basically the main idea is to get the delta luma line (brightness) of the colors close to zero, and try to get as close as you can to the reference points on the CIE diagram.