Originally Posted by Javs
Oh, and its pretty clear now, that I have gamut coverage issues. I am no longer going to chalk it up to user error, or not taking readings right. This thing is missing 8% of the gamut calibrated, end of story, its going back. The most I have ever seen in an uncalibrated state is 93%.
Green and Cyan are not where they need to be, they are acting as if there is no filter in the path at all. I know there is though since when I do the same tests with Manni's BT2020NF I get even less gamut.
Re luminance in HDR vs SDR, this is also what I concluded, especially after a jvc Autocal in my new SDR setting. I now aim for around 100nits for peak white in SDR (similar to what I aimed for in HDR) and cannot see any significant color difference along with my other settings.
Regarding your gamut issue, your unit show a classic undersaturation in green and cyan due to a wrong hue of green. It's all the colors at 100% sat between green and blue which are undersaturated. They would most likely be undersaturated in rec-709 as well, because the green filter pushes the saturation but can't do anything about the wrong hue. The reason why JVC tell you that it's within spec is because it's a very frequent issue, especially in lower end models, especially in the first batches in a production. There is no guarantee that a new unit will not have this issue. It's one of the things to check along with bright corners, convergence, streaking, etc.
I know you're a dealer so you might be able to cherry pick yours, but otherwise if all the other aspects are good, I would think twice before swapping. Unless you can see that colours are wrong, remember that there is very little content at 100% sat (what you measured) except in animation. Most of the content is inside the triangle, not at the edges. If you do a JVC autocal from one of my custom colour profiles, therefore have a gamut tracking near perfection in both rec709 and bt2020, these errors won't show much if at all because the inside of the gamut tracks properly, so colours will not be undersaturated.
Getting a good projector, in my opinion, is getting one that gives you a picture that doesn't show any visible defect with actual content. If you try to swap a unit because you can measure something wrong with patterns or when sticking your nose to the screen, you'll be chasing your tail. I've never seen a perfect unit. I've rejected a few due to stuck pixels in the middle of the screen, otherwise I try to see if I get a good balance between the main offender (bright corners, stuck/dead pixels, undersaturated gamut due to wrong hue, focus/convergence, native contrast, black and white uniformity, etc). If I do, I know it's a small miracle so I keep it if there is nothing that hurts my eyes with actual content from a normal watching distance (1 screen width).