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Pete D - thanks for the heroic attempts at a comparison. I say heroic, because trying to get various factors (like white point color) to be the same in different sets so you can compare the phosphors and matrices is VERY difficult. You cannot even do the white point and gray scale matching with a colorimeter (a device having multiple filters and sensors) unless the colorimeter has been calibrated for the particular phosphors. [Then how DO you calibrate it, you ask.] The only accurate electronic instrument to measure phosphor color is a spectroradiometer, which should be calibrated to a standard source traceable to NIST. However, spectroradiometers are much more expensive, and used to be much slower reading, than colorimeters. At Zenith, our usual technique was to use a colorimeter calibrated to match a spectroradiometer, with a different calibration setting for each new phosphor set.
The other way to guarantee correct white point and grayscale tracking is by means of an optical comparator that presents a D65 field and an immediately adjacent view of the screen to the person making the adjustment. We had one of these for a while at Zenith, but I haven't seen one in a long time. The optical comparitor gave very precise results for one particular observer - so precise that the next observer would get noticeably different results (looking in the comparator) depending on normal slight variatons in color vision from one person to the next. For example, one of our older engineers always required more blue current to match the comparator than I did. I think this was a combination of his brown eyes and age (indicating more pigmentation in the eye itself) vs. my blue eyes. I'd also guess that I require more blue than I used to as my eyes age. Color experts who have had cataract surgery on one eye have written papers on the greater blue-violet sensitivity when the lense is removed. Gas stove flames, in particular, may go from dull to vivid violet/blue. We have one engineer at work who had lens implants in both eyes - but the doctors put a UV blocking lens in one eye and a clear one in the other, and he reports he can see such differences between his two eyes.
A similar thing: if you wear glasses that turn dark in the sun (as I do), put them down on a white surface and see if they aren't slightly amber rather than fully clear indoors - this will affect your sensitivity to the blue phosphor, possibly to a greater extent on the newer tubes where the blue phosphor is more towards violet.
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