I'm interested to know what you mean by a 'mura' effect and am wondering whether a certain optical effect I'm getting with this monitor could be accounted for by that. What I'm finding is that, at anything other than a sitting position (ie. normal viewing position), the image will rapidly and unevenly dull/darken. More precisely, as I move my head/eyes to a more upward position so that I'm less square on to the monitor, saturation is lost and the screen takes on either a grey, milky appearance or sometimes a shadowy appearance. This seems to happen only in the vertical plane. The effect is very pronounced if, for instance, I move off my sitting position to a standing position. The steeper the vertical angle with the screen, the worse the effect.
I've thought that this might be a consequence of LG having removed the polariser layer on these screens a year or two ago. My older NEC monitor (sRGB only) certainly never suffered from this. It had excellent viewing angles all round. If this is due to the loss of the polariser then it's obviously been a retrograde step.
I've tested for it being anything to do with reflected light on the screen but the effect is still there even with the room fully darkened out. So, it's definitely emissive, not reflective (I began to wonder if was essential to use the hood). The effect is not there, either, if you view the screen at various vertical angles from a distance of, say, 2 yds away. So, this is all down to subtended angles. But, of course, that doesn't help, as normal viewing is at 2 ft, not 2 yds.
I'm not sure what to make of that erroneous recording of the resolution on the Certificate. I wouldn't call it a trivial mistake, as it now puts the integrity of my 241 in complete doubt. And, after all, this being a Spectraview version, I've paid extra for what's supposed to be a calibrated, all-but-perfect sample.
One possibility is that the technician typed in the completely wrong resolution, and that's all, and NEC unfortunately then issued the monitor from the factory without spotting the mistake. The other possibility is that the technician was measuring 271s at the time and erroneously put the serial no. of my 241, rather than that of a 271, down on the sheet. But we'll never know. Therefore, all the calibration figures accompanying that Certificate could refer to a completely different monitor, not mine. That said, I wouldn't feel too concerned about it if someone with the appropriate knowledge could reassure me that this doesn't matter in the long term and that the LUT values in the monitor are fixed and are the same for all 241s and 271s.