This is really great and quite interesting results as I wouldn’t have expected the CRT to be so much more bright! I’ve been lead to believe over the whole screen CRT’s are a little less bright than an SDR monitor. However my personal experience with a 2730 PVM is not that the case and a PVM is a lot brighter which ties in with your results.
So although interesting and confirming previous experience this isn’t quite what we’re after. Luminance is measured in cd/m2 i.e candellas per square meter. This is fine for a screen with constant brightness over it i.e meauring white on a LCD/OLED as RTings does but starts to pose problems for us on PVM’s where the brightness is variable across the screen i.e when you have scanlines the parts in between are dark and the center of the scanline is bright. Add onto that CRT’s are quite low res compared to modern LCD’s. As we all know 600TVL CRT has 800 lines across whereas a 4K CRT has 3840 pixels across meaning the density of emitting elements is far higher on an LCD.
So in order for an LCD to mimic a CRT displaying white we have to turn off/darken the vast majority of light emitting elements compared to a normal LCD displaying white. This is why we need the brightness to be far above a normal LCD to make up for the lack elements fully brightening themselves.
What all this mounts to is that we somehow need to measure the peak brightness within a scanline and measure its fall off.
Long and short is that I’m not sure how we do that?