RE: NEC PA271Q "Native" chromaticities
RE: NEC PA271Q "Native" chromaticities
- Subject: RE: NEC PA271Q "Native" chromaticities
- From: Wayne Bretl via colorsync-users <email@hidden>
- Date: Mon, 2 Dec 2019 19:19:47 -0700
A bit of technical discussion about NTSC and television:
SMPTE had no influence as far as I know on the selection of NTSC primaries. The
choices were made mainly by RCA as part of the second NTSC (National Television
Systems Committee; the first NTSC established monochrome standards in 1941).
The standards, adopted by the FCC, simply stated that the signal should be
"suitable" for the specified primaries, with no details. Because the early
image orthicon cameras were noisy and used drift-prone tube circuits, it was
impractical to use matrixing of the R,G,B signals to match the primaries, and
as a result the camera optical filters were carefully chosen to match the NTSC
phosphors. They also used the old trick of film and print reproduction in using
narrow band color separation filters to enhance the saturation of ordinary
object spectra. The noise limitations also meant that it was unreasonable to
actually match the desired gamma correction of 1/2.2 (cameras were actually
designed to about 1/1.75), so that acceptable tone rendition was obtained by
careful exposure plus playing with the black level. The resulting signal gave a
high-contrast reproduction that was in a way similar to Technicolor, and
partially compensated for the low contrast ratio of early CRTs due to their
high screen reflectivity. However, the lowlight contrast was lost in the
process, and gradually improved as the display contrast ratios got better, and
rather dramatically when the image orthicons were replaced by the much less
noisy Plumbicon pickup tubes, plus gamma correction actually 1/2.2 and proper
color matrixing.
Even with these changes, there is typically a discrepancy between the
saturation capability of highlights and lowlights in subtractive vs. additive
systems, with subtractive systems (printing) excelling in lowlights, and
emissive displays excelling in highlights. The net result is that a display
with NTSC primaries, with correct black level and viewed under dim ambient, can
equal or exceed the gamut of most surface colors, whereas, an sRGB display is
lacking in at least the cyan and "true green" regions.
The compromise to Rec 709 is strictly because those were the primaries that
were available that made bright CRTs with nearly equal gun currents. The
unequal gun currents in early "NTSC" CRTs were a terrible headache in terms of
maintaining equal spot size and gray scale tracking between the guns. One
should also note that the psychophysical sensation of "colorfulness" is
affected greatly by display brightness, and the TV companies and their
customers recognized this, although they may not have had the research to
support it at the time. In any case, customers much preferred brighter
pictures, a difference they could see immediately and continually, while they
could not detect gamut limitations without seeing the TV side by side with the
program stage itself.
-----Original Message-----
From: colorsync-users
<colorsync-users-bounces+waynebretl=email@hidden> On Behalf Of Wire
~ via colorsync-users
Sent: Monday, December 02, 2019 6:21 PM
To: email@hidden
Subject: Re: NEC PA271Q "Native" chromaticities
Of course, it brings nothing to the party today! It's maligned today. Yet,
it's an excellent compromise of concerns from the perspective of history.
My earlier point—which context is a bit elusive here—was that if you think
eciRGB is a great compromise today—and over at DisplayCal forum a knowledgeable
user strongly makes this point—well I say: isn't it interesting that eciRGB
gamut is NTSC 1953!
So what happened? Did color engineers just not care? Why was there this
compromise toward 709?
And given that everyone who has ever owned a personal computer owes a debt to
the television industry, it's hard to say "OMG why is my work so hamstrung by
this outdated display standard"? In 1980s computing environments, color itself
was considered an expensive option that crossed off purchase reqs. In my
experience, it was the rise of the web that made color mandatory.
I'd be interested in anecdotes about how the limits of sRGB affect color
printing from an artistic perspective.
For example, I once met a guy who loved orchids and was disappointed with his
inkjet printer because it couldn't do pinks (magentas) that looks anything like
his 2004 era color PC display. He wasn't concerned about matching the flowers!
Lol
The history of great art photography is black-and-white. And it still is.
For example, the movie industry had the marvel of Technicolor which it showed
off in prestige roadshow pictures. Is there a similar moment in color still
printing? Yes Cibachrome was great looking, just like Kodachrome is loved. But
is there an Ansel Adams of color?
So at what point would you say that color radically changed art printing?
Not the photography of other media, but as an artistic aspect in and of itself.
Desktop publishing color has traditionally about simulation and visualization
of pre-existing media, and how printing gamuts affect this.
Most color fidelity convos go something like "Well this system can't reproduce
this other thing, so..." and the requirement gets constructed from a simulation
requirement. In 1953, was SMPTE thinking "Eventually we'll use this tech to
simulate 6 color inkjets"?
So I'm curious to hear you put the statement "you can't get any worse than
sRGB" into a perspective of a history of printing, and was there a seminal
point at which transcending the limits of sRGB profoundly changed photography?
Yea, sRGB is limited, no argument. But I've never come across anyone who from a
pure perspective of aesthetic appreciation looked at an sRGB display and
remarked, that's OK but it's missing something. Of course you can see
differences, and once you have seen them you can train yourself to notice in
rarified conditions. However, I've heard plenty of people say "my display color
is too intense" when looking at web color on a WCG display and wonder what's
going wrong.
On Mon, Dec 2, 2019 at 3:58 PM Andrew Rodney via colorsync-users <
email@hidden> wrote:
>
> > On Dec 2, 2019, at 4:44 PM, Wire ~ via colorsync-users <
> email@hidden> wrote:
> >
> > My current peeve is the denigration of sRGB. It's a color-space that
> makes
> > so much sense.
>
> Well it did in circa 1994 or so (with CRTs). I don't see what it
> brings to the party today. And far, far too many urban legends surrounding it.
>
> > And I'm super excited about new wide-gamut displays, and more color.
>
> More? Maybe wider gamut which is nothing really that new. Even on
> iPhone and iPad.
>
> Anyway, for those of us still printing, you can't do much worse than
> sRGB ;-}
>
> Andrew Rodney
> http://www.digitaldog.net/ <http://www.digitaldog.net/>
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