"Dave Plowman (News)" wrote in message
...
In article , Arfa Daily
wrote:
Contrary to what you believe about the phosphors on CRTs, I don't
believe that there has been any significant change in their colour
rendition capabilities since the earliest delta gun tubes in the uk,
which I worked with from about 1970

Oh, but there was. The original delta gun shadow mask tubes used the
correct NTSC phosphors. Which gave a pretty pure red. The rot really came
in with PIL tubes which used a very 'orange' red phosphor simply because
it allowed a brighter picture. And that had real implications to flesh
tones. Took many years before that was corrected.

--
*We have enough youth, how about a fountain of Smart?

Dave Plowman London SW
To e-mail, change noise into sound.

Hmmm. I can't say that I remember slot mask / in line tubes producing any
worse a picture, in terms of colour rendition, than deltas. Certainly, they
were an improvement in convergence and extremity focus - perhaps even
overall 'sharpness'. If the colour / output of the red phosphor did not
match the transmitted weighting factor for that colour, I would have thought
that this would have caused serious problems for rendering whites and greys
correctly, and would have had a significantly pronounced effect on the
ability of the tube to render subtleties such as flesh tones. An 'orangy'
red would have screwed about with the chromaticity diagram, and completely
altered the pallette of colours that the tube *could* produce from just
three primaries. It would be like taking a printer's pantone colour chart,
and redefining all the hues, wouldn't it ?

We had some pretty fussy customers back then with serious pots of money, and
I can't recall any colour accuracy issues ever arising - aside from one
particular customer who used to complain on a weekly basis that colours were
"bleeding through" (convergence issues !) and in the summer that there was
something wrong because the grass in front of the wicket on the cricket, was
yellow ...

Nor can I recall any mention of this either in the trade press, or at our
company's training school, which was recognised as being one of the best
that there was.

Anyway, going back to chromaticity diagrams, did you look at the link to an
explanation of 'non-spectral colours' to see what I was talking about,
outside of any differences which there may or may not have been with the
phosphor colours ?

Arfa