1954 NTSC “Correct” Video.

[etype2]

Originally Posted by old_tv_nut

The ideal would be a NTSC tape played on its original type of machine with no adjustments beyond chroma amplitude and phase, and viewed on a 15GP22. Any additional stages in between (like decoding the NTSC into YCrCb for DVD and recoding as NTSC composite DVD player output) likely will (or in many cases definitely will) introduce modfications to match (or mismatch) modern TVs, monitors or computer screens.

A colorimetric analysis of the TK-41 spectral response shows that it was an excellent match to the original NTSC phosphors. This quickly went haywire as TV makers changed the white point and the phosphor primary colors themselves (particularly the greeen, but also the blue) in the quest for brighter pictures, and further when later camera makers tweaked the cameras to cater to the newer receivers and monitors. The train didn't get back on track until PAL standardized their cameras to match the modern phosphors. Then sRGB for computer stills and the color standards for HDTV also adopted the same primaries. This doesn't mean that camera makers necessarily did it by the book. Sony HD cameras in particular had a color rendition all their own, with particularly bright yellows - but the standardization meant that they could guarantee that all HDTVs would show the colors the way Sony intended. The Sony camera color may have been fudged to show the paler skin tones preferred in Japan, but I don't know for sure. I do know that we had to modify the matrix in the early Sony cameras to match the standard colors on the test chart (which the BTS cameras already did) when we were creating the subjective comparison test material for the U.S. HDTV format wars.

Very interesting, so now I have to find a quad machine. :-)

In a 1954 publication, Westinghouse claims the red phosphor in the 15GP22 had a “slow persistence causing fuzzy images”. Would this be one one of the reasons phosphors were changed? I know brightness as you say was an issue.