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30-bit Color on 24-bit Hardware

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Anonymous
a b U Graphics card
September 24, 2004 2:25:24 AM

Archived from groups: comp.graphics.algorithms,comp.graphics.visualization,comp.sys.ibm.pc.hardware.video,rec.photo.digital,sci.image.processing (More info?)

Hi.

I just wanted to get the word out there for any who may be interested
about this display fidelity extension stuff I've been working on. It's
basically about getting 24-bit hardware to perceptually display 30-bit
color.

General information is available at <http://www.silvasdigital.com/xdf&gt;.

The "meat and potatoes" info is available in the Project Summary and
Findings Report at . . .
<http://www.silvasdigital.com/xdf/XDF Project Summary and Findings Report.pdf>

All the info is free--I don't think there's anything proprietary in
there (though I'm not any kind of legal council)--but since I *have*
spent quite a lot of time on this and I do have bills to pay, I'm only
providing the tech demo (a hi-fi image viewer for Windows) in return
for donations.

Thanks and I hope you find the info to have been worth checking out,
- Ron

More about : bit color bit hardware

September 24, 2004 4:41:15 AM

Archived from groups: comp.graphics.algorithms,comp.graphics.visualization,comp.sys.ibm.pc.hardware.video,rec.photo.digital,sci.image.processing (More info?)

"Ron W. Silvas" <contact@silvasdigital.com> wrote in message news:c516aeb9.0409232125.2ab3ed4d@posting.google.com...
> Hi.
>
> I just wanted to get the word out there for any who may be interested
> about this display fidelity extension stuff I've been working on. It's
> basically about getting 24-bit hardware to perceptually display 30-bit
> color.
>
> General information is available at <http://www.silvasdigital.com/xdf&gt;.
>
> The "meat and potatoes" info is available in the Project Summary and
> Findings Report at . . .
> <http://www.silvasdigital.com/xdf/XDF Project Summary and Findings Report.pdf>
>
> All the info is free--I don't think there's anything proprietary in
> there (though I'm not any kind of legal council)--but since I *have*
> spent quite a lot of time on this and I do have bills to pay, I'm only
> providing the tech demo (a hi-fi image viewer for Windows) in return
> for donations.
>
> Thanks and I hope you find the info to have been worth checking out,

Ron, have you written an API for extended-bit printer
drivers? Windows is limited to 24-bit output, and without
the aforementioned API your technology is of very limited
use (at least under Windows).

Rick
Anonymous
a b U Graphics card
September 24, 2004 3:02:12 PM

Archived from groups: comp.graphics.algorithms,comp.graphics.visualization,comp.sys.ibm.pc.hardware.video,rec.photo.digital,sci.image.processing (More info?)

"Rick" <me@privacy.net> wrote in message news:<2ri1d1F1b8f8pU1@uni-berlin.de>...
> Ron, have you written an API for extended-bit printer
> drivers? Windows is limited to 24-bit output, and without
> the aforementioned API your technology is of very limited
> use (at least under Windows).

Hi, Rick.

No, I haven't written any sort of print driver.

And, like you, I suspect that visualizing in color depths beyond what
your target output device is capable of producing might not be the best
idea, but . . .

Paper is by no means the only target medium out there these days,
right? The video game and multimedia industry produces content for
display on computer monitors and televisions, the motion picture
industry--including their animation and special effects studios--
produce content for film and 30-bit digital projection, and I believe
medical imaging usually requires greater than 24-bit color fidelity (or
greater than 8-bit grayscale, etc.).

And even if 30-bit color didn't have any practical uses–-which is not
the case–-we'd only know that by first researching it, right? I'm just
making some of that research available to those who are similarly
interested.

Thank you for asking about this,
- Ron
Related resources
Anonymous
a b U Graphics card
September 24, 2004 3:44:20 PM

Archived from groups: comp.graphics.algorithms,comp.graphics.visualization,comp.sys.ibm.pc.hardware.video,rec.photo.digital,sci.image.processing (More info?)

"Ron W. Silvas" <contact@silvasdigital.com> wrote in message
news:c516aeb9.0409232125.2ab3ed4d@posting.google.com...
> Hi.
>
> I just wanted to get the word out there for any who may be interested
> about this display fidelity extension stuff I've been working on. It's
> basically about getting 24-bit hardware to perceptually display 30-bit
> color.
>

Perceptually, would anybody see a difference?
Anonymous
a b U Graphics card
September 24, 2004 3:44:21 PM

Archived from groups: comp.graphics.algorithms,comp.graphics.visualization,comp.sys.ibm.pc.hardware.video,rec.photo.digital,sci.image.processing (More info?)

Atreju <someone@who.hates.junkmail> writes:

> On Fri, 24 Sep 2004 11:44:20 +0100, "Des Perado" <des@per.ado> wrote:
>
> >
> >"Ron W. Silvas" <contact@silvasdigital.com> wrote in message
> >news:c516aeb9.0409232125.2ab3ed4d@posting.google.com...
> >> Hi.
> >>
> >> I just wanted to get the word out there for any who may be interested
> >> about this display fidelity extension stuff I've been working on. It's
> >> basically about getting 24-bit hardware to perceptually display 30-bit
> >> color.
> >>
> >
> >Perceptually, would anybody see a difference?
>
> I know my eyes usually tune out at about 150,000 colors ;-)

It's not that simple. The colors from a normal display aren't
distributed evenly in the human color space, and there's a difference
between the contrast you can see between two adjacent colors and the
total number of colors in an image. So it's quite possible, depending
on the conditions, for 24 bits to be inadequate. I would expect this
more for LCD's than for CRT's, though, both because of their dynamic
range and because the nonlinearity of a CRT actually helps. I think
many LCD's use temporal dithering already, as they tend to be a bit
short of full 24-bit capability.

--
-Stephen H. Westin
Any information or opinions in this message are mine: they do not
represent the position of Cornell University or any of its sponsors.
Anonymous
a b U Graphics card
September 24, 2004 4:08:54 PM

Archived from groups: comp.graphics.algorithms,comp.graphics.visualization,comp.sys.ibm.pc.hardware.video,rec.photo.digital,sci.image.processing (More info?)

"Des Perado" <des@per.ado> wrote in message news:<2ric4nF19vv8dU1@uni-berlin.de>...
> Perceptually, would anybody see a difference?

If your question is . . .
"Would anybody see a difference between the true 30-bit color (of, say,
a Matrox Parhelia) and the synthesized 30-bit color (which I'm talking
about)?"

The short answer is: No, I don't think they would–Not if the 30-bit
synthesizing is implemented correctly.

But if your question is . . .
"Would anybody see a difference between 24-bit color and 30-bit color?"

As Mononen pointed out, the short answer is: Yes they would, but only
in some images. (Thanks, Mononen. =)


More detailed answers to these questions can found in . . .
<http://www.silvasdigital.com/xdf/XDF Project Summary and Findings Report.pdf>
.. . . with the latter question dealt with in the
"24-bit Color vs. 30-bit Color" section.

Thank you for the discussion,
- Ron
Anonymous
a b U Graphics card
September 24, 2004 5:02:53 PM

Archived from groups: comp.graphics.algorithms,comp.graphics.visualization,comp.sys.ibm.pc.hardware.video,rec.photo.digital,sci.image.processing (More info?)

westin*nospam@graphics.cornell.edu (Stephen H. Westin) wrote in message news:<s0656321or.fsf@diesel.graphics.cornell.edu>...
> It's not that simple. The colors from a normal display aren't
> distributed evenly in the human color space...So it's quite possible,
> depending on the conditions, for 24 bits to be inadequate. I would
> expect this more for LCD's than for CRT's, though, both because of
> their dynamic range...I think many LCD's use temporal dithering
> already, as they tend to be a bit short of full 24-bit capability.

Hi, Mr. Westin.

Thank you for pointing that out--about the difference between human
vision and the color space of RGB displays. I tried to deal with that
a little in the pre-mentioned PDF's "Beyond 24-bit Color" section,
where I mention that "24-bit color allows for hue and saturation level
precision beyond human visual sensitivity but fails to naturally allow
for the specification and display of the many hundreds of
intensity/brightness levels per color that humans can visually
distinguish."

I've found that 24-bit artifacts are quite demonstratable on both CRTs
and LCDs, alike, (as can be experienced with the previously mentioned
tech demo) but I believe that, if anything, they would be more
noticeable on CRTs because the higher dynamic range of a CRT means that
an 8-bit color channel's 256 intensity/brightness levels have that much
more perceptual space to cover, right?

I believe you are correct about LCDs already using temporal dithering--
often to extend native 18-bit LCD hardware (6 bits per RGB channel) to
24-bit color. But I believe there *are* true 24-bit LCDs also, and what
I find interesting is that, apparently, some companies are starting to
use temporal dithering in *them* to extend them to 30-bit color--BUT,
unless there's some kind of good hardware reason to do this (which I
wouldn't know about), my research seems to indicate that they should
instead be using traditional *spatial* dithering for this extension
because . . . If properly implemented, spatial dithering can be used to
extend 24-bit color to 30-bit color with *none of its traditional
dithering noise visible* because of the perceptual closeness of 24-bit
color space neighbors (More about that in the PDF).

Thanks again for pointing out the color space deal, and thank you for
the discussion,
- Ron
Anonymous
a b U Graphics card
September 24, 2004 5:37:44 PM

Archived from groups: comp.graphics.algorithms,comp.graphics.visualization,comp.sys.ibm.pc.hardware.video,rec.photo.digital,sci.image.processing (More info?)

On Fri, 24 Sep 2004 11:44:20 +0100, "Des Perado" <des@per.ado> wrote:

>
>"Ron W. Silvas" <contact@silvasdigital.com> wrote in message
>news:c516aeb9.0409232125.2ab3ed4d@posting.google.com...
>> Hi.
>>
>> I just wanted to get the word out there for any who may be interested
>> about this display fidelity extension stuff I've been working on. It's
>> basically about getting 24-bit hardware to perceptually display 30-bit
>> color.
>>
>
>Perceptually, would anybody see a difference?
>

I know my eyes usually tune out at about 150,000 colors ;-)


---Atreju---
Anonymous
a b U Graphics card
September 25, 2004 2:50:18 AM

Archived from groups: comp.graphics.algorithms,comp.graphics.visualization,comp.sys.ibm.pc.hardware.video,rec.photo.digital,sci.image.processing (More info?)

"Ron W. Silvas" <contact@silvasdigital.com> wrote in message
news:c516aeb9.0409241202.6a4f5b6c@posting.google.com...
> I've found that 24-bit artifacts are quite demonstratable on both CRTs
> and LCDs, alike, (as can be experienced with the previously mentioned
> tech demo) but I believe that, if anything, they would be more
> noticeable on CRTs because the higher dynamic range of a CRT means that
> an 8-bit color channel's 256 intensity/brightness levels have that much
> more perceptual space to cover, right?

I've been following this thread with interest, but a couple of
comments seem appropriate at this point.

First - what "higher dynamic range" of the CRT? Neither the
color gamut or the contrast of the typical CRT display is
much different that what can be obtained with the LCD.
What I think the problem here really is, is a difference in the
response curves of the two technologies. CRTs have a very
nice (perceptually) "gamma" sort of response, whereas LCDs
have a perceptually-nastier "S-shaped" response that cannot
adequately be compensated for with only 8 bits per channel,
not if you still intend to have 8 bit/channel of perceptually linear
intensity control. The solution here is greater dynamic range
(bit depth) at the panel (i.e., at the driver level), to permit
compensation for the panel's response and thus present a
"CRT-like" 8-bit input. Fortunately, we ARE starting to see
10-bit LCD drivers entering the market.

Bob M.
September 25, 2004 2:50:19 AM

Archived from groups: comp.graphics.algorithms,comp.graphics.visualization,comp.sys.ibm.pc.hardware.video,rec.photo.digital,sci.image.processing (More info?)

"Bob Myers" <nospamplease@address.invalid> wrote in message news:Kw15d.11687$MS.7082@news.cpqcorp.net...
>
> "Ron W. Silvas" <contact@silvasdigital.com> wrote in message
> news:c516aeb9.0409241202.6a4f5b6c@posting.google.com...
> > I've found that 24-bit artifacts are quite demonstratable on both CRTs
> > and LCDs, alike, (as can be experienced with the previously mentioned
> > tech demo) but I believe that, if anything, they would be more
> > noticeable on CRTs because the higher dynamic range of a CRT means that
> > an 8-bit color channel's 256 intensity/brightness levels have that much
> > more perceptual space to cover, right?
>
> I've been following this thread with interest, but a couple of
> comments seem appropriate at this point.
>
> First - what "higher dynamic range" of the CRT? Neither the
> color gamut or the contrast of the typical CRT display is
> much different that what can be obtained with the LCD.

Nonsense. The backlight technology used in LCDs (at least
those in the con/prosumer range) precludes the possibility that
they can match the gamut of a decent CRT. E.g. a $700
Mitsubishi 2070 easily outgamuts a $1300 Apple Cinema
Display.

> What I think the problem here really is, is a difference in the
> response curves of the two technologies. CRTs have a very
> nice (perceptually) "gamma" sort of response, whereas LCDs
> have a perceptually-nastier "S-shaped" response that cannot
> adequately be compensated for with only 8 bits per channel,
> not if you still intend to have 8 bit/channel of perceptually linear
> intensity control. The solution here is greater dynamic range
> (bit depth) at the panel (i.e., at the driver level), to permit
> compensation for the panel's response and thus present a
> "CRT-like" 8-bit input. Fortunately, we ARE starting to see
> 10-bit LCD drivers entering the market.

More nonsense. No amount of compensation will overcome
the limitations of LCD's backlight technology. One has the
choice of losing near blacks altogether, or settling for a
constant and muddy bluish or grayish glow instead of black.

Rick
Anonymous
a b U Graphics card
September 25, 2004 9:01:14 PM

Archived from groups: comp.graphics.algorithms,comp.graphics.visualization,comp.sys.ibm.pc.hardware.video,rec.photo.digital,sci.image.processing (More info?)

"Bob Myers" <nospamplease@address.invalid> wrote in message news:<Kw15d.11687$MS.7082@news.cpqcorp.net>...
> "Ron W. Silvas" <contact@silvasdigital.com> wrote in message
> news:c516aeb9.0409241202.6a4f5b6c@posting.google.com...
> > I've found that 24-bit artifacts are quite demonstratable on both CRTs
> > and LCDs, alike, (as can be experienced with the previously mentioned
> > tech demo) but I believe that, if anything, they would be more
> > noticeable on CRTs because the higher dynamic range of a CRT means that
> > an 8-bit color channel's 256 intensity/brightness levels have that much
> > more perceptual space to cover, right?
>
> I've been following this thread with interest, but a couple of
> comments seem appropriate at this point.
>
> First - what "higher dynamic range" of the CRT? Neither the
> color gamut or the contrast of the typical CRT display is
> much different that what can be obtained with the LCD.
> What I think the problem here really is, is a difference in the
> response curves of the two technologies. CRTs have a very
> nice (perceptually) "gamma" sort of response, whereas LCDs
> have a perceptually-nastier "S-shaped" response that cannot
> adequately be compensated for with only 8 bits per channel,
> not if you still intend to have 8 bit/channel of perceptually linear
> intensity control. The solution here is greater dynamic range
> (bit depth) at the panel (i.e., at the driver level), to permit
> compensation for the panel's response and thus present a
> "CRT-like" 8-bit input. Fortunately, we ARE starting to see
> 10-bit LCD drivers entering the market.
>
> Bob M.

Hi, Mr. Myers.

It might be time for me to exit from this branch of the
discussion, as I am admittedly not very knowledgeable about the
areas being discussed (dynamic ranges, contrast ratios,
hardware behavioral differences between LCD and CRT
technologies, etc.). =)

My earlier comment . . .

> > "I believe that, if anything, they would be more noticeable
> > on CRTs because the higher dynamic range of a CRT . . . "

.. . . was a jump to a conclusion on my part–I should have asked
Mr. Westin if he could explain to me his comment about the
different dynamic ranges before I commented on that. Totally
my mistake.

> What I think the problem here really is...the response curves . . .

You may be referring to a legitimate problem that needs solving,
but I wouldn't know, so I'll leave that for you and others to
discuss, BUT . . .

The problem that this project dealt with (and successfully
overcame) was simply this . . .

Quick & Dirty:
o 24-bit color's 256 intensity levels per channel are not
enough.
(True even where gamma config'd to *exactly* correspond to
vision's intensity response.)
o 27-bit color's >500 intensity levels per channel is close,
but not enough.
o 30-bit color's >1000 intensity levels per channel *is*
finally enough.
o 30-bit color display is desirable.
o 30-bit color display on common 24-bit hardware would be a
nice bonus, and . . .

It works. On CRTs and LCDs, alike. No special hardware
requirements. No special OS support needed.

- Ron
Anonymous
a b U Graphics card
September 27, 2004 12:20:50 PM

Archived from groups: comp.graphics.algorithms,comp.graphics.visualization,comp.sys.ibm.pc.hardware.video,rec.photo.digital,sci.image.processing (More info?)

"Bob Myers" <nospamplease@address.invalid> wrote:

>CRTs have a very
>nice (perceptually) "gamma" sort of response, whereas LCDs
>have a perceptually-nastier "S-shaped" response that cannot
>adequately be compensated for with only 8 bits per channel,
>not if you still intend to have 8 bit/channel of perceptually linear
>intensity control. The solution here is greater dynamic range
>(bit depth) at the panel (i.e., at the driver level), to permit
>compensation for the panel's response and thus present a
>"CRT-like" 8-bit input. Fortunately, we ARE starting to see
>10-bit LCD drivers entering the market.

You feel that "more bits" is the best solution to a non-linear
response? Seems to me the panel could (and, indeed, does), compensate
for this.
Anonymous
a b U Graphics card
September 27, 2004 12:23:13 PM

Archived from groups: comp.graphics.algorithms,comp.graphics.visualization,comp.sys.ibm.pc.hardware.video,rec.photo.digital,sci.image.processing (More info?)

contact@silvasdigital.com (Ron W. Silvas) wrote:

>But if your question is . . .
>"Would anybody see a difference between 24-bit color and 30-bit color?"
>
>As Mononen pointed out, the short answer is: Yes they would, but only
>in some images. (Thanks, Mononen. =)

Maybe, under perfect conditions.

I'd like to see these alleged "some images"...
Anonymous
a b U Graphics card
September 27, 2004 10:04:15 PM

Archived from groups: comp.graphics.algorithms,comp.graphics.visualization,comp.sys.ibm.pc.hardware.video,rec.photo.digital,sci.image.processing (More info?)

"Rick" <me@privacy.net> writes:

> "Bob Myers" <nospamplease@address.invalid> wrote in message news:Kw15d.11687$MS.7082@news.cpqcorp.net...
> >
> > "Ron W. Silvas" <contact@silvasdigital.com> wrote in message
> > news:c516aeb9.0409241202.6a4f5b6c@posting.google.com...
> > > I've found that 24-bit artifacts are quite demonstratable on both CRTs
> > > and LCDs, alike, (as can be experienced with the previously mentioned
> > > tech demo) but I believe that, if anything, they would be more
> > > noticeable on CRTs because the higher dynamic range of a CRT means that
> > > an 8-bit color channel's 256 intensity/brightness levels have that much
> > > more perceptual space to cover, right?
> >
> > I've been following this thread with interest, but a couple of
> > comments seem appropriate at this point.
> >
> > First - what "higher dynamic range" of the CRT? Neither the
> > color gamut or the contrast of the typical CRT display is
> > much different that what can be obtained with the LCD.
>
> Nonsense. The backlight technology used in LCDs (at least
> those in the con/prosumer range) precludes the possibility that
> they can match the gamut of a decent CRT. E.g. a $700
> Mitsubishi 2070 easily outgamuts a $1300 Apple Cinema
> Display.

Really? Where did you find this out? Do you have the respective primary
chromaticities handy?

> > What I think the problem here really is, is a difference in the
> > response curves of the two technologies. CRTs have a very
> > nice (perceptually) "gamma" sort of response, whereas LCDs
> > have a perceptually-nastier "S-shaped" response that cannot
> > adequately be compensated for with only 8 bits per channel,
> > not if you still intend to have 8 bit/channel of perceptually linear
> > intensity control. The solution here is greater dynamic range
> > (bit depth) at the panel (i.e., at the driver level), to permit
> > compensation for the panel's response and thus present a
> > "CRT-like" 8-bit input. Fortunately, we ARE starting to see
> > 10-bit LCD drivers entering the market.
>
> More nonsense. No amount of compensation will overcome
> the limitations of LCD's backlight technology. One has the
> choice of losing near blacks altogether, or settling for a
> constant and muddy bluish or grayish glow instead of black.

In any reasonable lighting level, a good LCD will be at least
competitive in dynamic range with any CRT. The days of all CRT's being
better than all LCD's are past.

--
-Stephen H. Westin
Any information or opinions in this message are mine: they do not
represent the position of Cornell University or any of its sponsors.
September 27, 2004 10:04:16 PM

Archived from groups: comp.graphics.algorithms,comp.graphics.visualization,comp.sys.ibm.pc.hardware.video,rec.photo.digital,sci.image.processing (More info?)

"Stephen H. Westin" <westin*nospam@graphics.cornell.edu> wrote in message news:s0acvbmkrk.fsf@diesel.graphics.cornell.edu...
> "Rick" <me@privacy.net> writes:
>
> > "Bob Myers" <nospamplease@address.invalid> wrote in message news:Kw15d.11687$MS.7082@news.cpqcorp.net...
> > >
> > > "Ron W. Silvas" <contact@silvasdigital.com> wrote in message
> > > news:c516aeb9.0409241202.6a4f5b6c@posting.google.com...
> > > > I've found that 24-bit artifacts are quite demonstratable on both CRTs
> > > > and LCDs, alike, (as can be experienced with the previously mentioned
> > > > tech demo) but I believe that, if anything, they would be more
> > > > noticeable on CRTs because the higher dynamic range of a CRT means that
> > > > an 8-bit color channel's 256 intensity/brightness levels have that much
> > > > more perceptual space to cover, right?
> > >
> > > I've been following this thread with interest, but a couple of
> > > comments seem appropriate at this point.
> > >
> > > First - what "higher dynamic range" of the CRT? Neither the
> > > color gamut or the contrast of the typical CRT display is
> > > much different that what can be obtained with the LCD.
> >
> > Nonsense. The backlight technology used in LCDs (at least
> > those in the con/prosumer range) precludes the possibility that
> > they can match the gamut of a decent CRT. E.g. a $700
> > Mitsubishi 2070 easily outgamuts a $1300 Apple Cinema
> > Display.
>
> Really? Where did you find this out? Do you have the respective primary
> chromaticities handy?
>
> > > What I think the problem here really is, is a difference in the
> > > response curves of the two technologies. CRTs have a very
> > > nice (perceptually) "gamma" sort of response, whereas LCDs
> > > have a perceptually-nastier "S-shaped" response that cannot
> > > adequately be compensated for with only 8 bits per channel,
> > > not if you still intend to have 8 bit/channel of perceptually linear
> > > intensity control. The solution here is greater dynamic range
> > > (bit depth) at the panel (i.e., at the driver level), to permit
> > > compensation for the panel's response and thus present a
> > > "CRT-like" 8-bit input. Fortunately, we ARE starting to see
> > > 10-bit LCD drivers entering the market.
> >
> > More nonsense. No amount of compensation will overcome
> > the limitations of LCD's backlight technology. One has the
> > choice of losing near blacks altogether, or settling for a
> > constant and muddy bluish or grayish glow instead of black.
>
> In any reasonable lighting level, a good LCD will be at least
> competitive in dynamic range with any CRT. The days of all CRT's being
> better than all LCD's are past.

We've been through this, Stephen, where you pull out your
highly misleading "research paper" and make highly misleading
claims based on misleading information.

The bottom line? Virtually no professional graphic shops use
LCDs. Why? Because any serious attempt at color correcting
on con/prosumer LCDs is an exercise in futility. End of story.

Rick
Anonymous
a b U Graphics card
September 27, 2004 10:38:59 PM

Archived from groups: comp.graphics.algorithms,comp.graphics.visualization,comp.sys.ibm.pc.hardware.video,rec.photo.digital,sci.image.processing (More info?)

"Rick" <me@privacy.net> wrote in message
news:2rjqkmF1bdk87U1@vni-berlin.de...
> Nonsense. The backlight technology vsed in LCDs (at least
> those in the con/prosvmer range) preclvdes the possibility that
> they can match the gamvt of a decent CRT. E.g. a $700
> Mitsvbishi 2070 easily ovtgamvts a $1300 Apple Cinema
> Display.

The gamvt of any display is determined by its primaries.
Typical CRT primaries are generally very close to those
given in standards svch as sRGB, or the "EBU" (Evropean
Broadcast Union) phosphor set. These are as follows:

sRGB (IEC 61966-2.1):

Red - 0.640, 0.330
Green - 0.300, 0.600 (for EBU, this is 0.290, 0.600)
Blve - 0.150, 0.060

I'm not svre exactly WHICH of the "Apple Cinema"
displays yov're talking abovt, bvt the latest pvblished data
I have on the 23" claims the following:

Red - 0.640, 0.332
Green - 0.288, 0.601
Blve - 0.146, 0.065

I've never measvred the Apple display specifically, bvt these
are pretty close to what I wovld expect based on tests of similar
contemporary panels.

(All of the above, by the way, in 1931 CIE xy coordinates.)

Those look very CRT-ish to me; if anything, the green is
slightly better than the sRGB/EBU standards, the red is
very slightly more satvrated, and the blve might be very
slightly less. So vnless yov're vsing "gamvt" to mean something
very different here, I am afraid I don't see yovr point.


> More nonsense. No amovnt of compensation will overcome
> the limitations of LCD's backlight technology. One has the
> choice of losing near blacks altogether, or settling for a
> constant and mvddy blvish or grayish glow instead of black.

I don't think yov vnderstood the point here, which had to do
with the lvminance response cvrve of the two technologies, not
the backlighting or anything related. Perhaps yov covld elaborate
a bit.

Bob M.
Anonymous
a b U Graphics card
September 27, 2004 10:42:28 PM

Archived from groups: comp.graphics.algorithms,comp.graphics.visualization,comp.sys.ibm.pc.hardware.video,rec.photo.digital,sci.image.processing (More info?)

"chrisv" <chrisv@nospam.invalid> wrote in message
news:o n4gl09e14bdf0be7a6r9jq6c3vur7733u@4ax.com...
> You feel that "more bits" is the best solution to a non-linear
> response? Seems to me the panel could (and, indeed, does), compensate
> for this.

More bits AT THE DRIVERS, which does not necessarily
translate to more bits at the display interface. The problem
here is that the PANEL does not compensate for the
response - any compensation which occurs happens in the
LCD controller, which is part of the monitor's interface
circuitry (i.e., it's between the panel proper and the outside
world). The problem here is that the controller only has eight
bits per color, at the PANEL interface, to play with, and any
of that that's used in doing the response compensation there
eats into the actual range that's available at the interface to the
graphics hardware. This can (and has) resulted in some rather
obvious artifacts, which generally show up when trying to do
such things as 8-bit grayscale patterns and the like.

Bob M.
Anonymous
a b U Graphics card
September 28, 2004 2:00:05 PM

Archived from groups: comp.graphics.algorithms,comp.graphics.visualization,comp.sys.ibm.pc.hardware.video,rec.photo.digital,sci.image.processing (More info?)

"Rick" <me@privacy.net> writes:

> "Stephen H. Westin" <westin*nospam@graphics.cornell.edu> wrote in message news:s0acvbmkrk.fsf@diesel.graphics.cornell.edu...
> > "Rick" <me@privacy.net> writes:
> >
> > > "Bob Myers" <nospamplease@address.invalid> wrote in message news:Kw15d.11687$MS.7082@news.cpqcorp.net...
> > > >
> > > > "Ron W. Silvas" <contact@silvasdigital.com> wrote in message
> > > > news:c516aeb9.0409241202.6a4f5b6c@posting.google.com...
> > > > > I've found that 24-bit artifacts are quite demonstratable on both CRTs
> > > > > and LCDs, alike, (as can be experienced with the previously mentioned
> > > > > tech demo) but I believe that, if anything, they would be more
> > > > > noticeable on CRTs because the higher dynamic range of a CRT means that
> > > > > an 8-bit color channel's 256 intensity/brightness levels have that much
> > > > > more perceptual space to cover, right?
> > > >
> > > > I've been following this thread with interest, but a couple of
> > > > comments seem appropriate at this point.
> > > >
> > > > First - what "higher dynamic range" of the CRT? Neither the
> > > > color gamut or the contrast of the typical CRT display is
> > > > much different that what can be obtained with the LCD.
> > >
> > > Nonsense. The backlight technology used in LCDs (at least
> > > those in the con/prosumer range) precludes the possibility that
> > > they can match the gamut of a decent CRT. E.g. a $700
> > > Mitsubishi 2070 easily outgamuts a $1300 Apple Cinema
> > > Display.
> >
> > Really? Where did you find this out? Do you have the respective primary
> > chromaticities handy?

<snip>

> > In any reasonable lighting level, a good LCD will be at least
> > competitive in dynamic range with any CRT. The days of all CRT's being
> > better than all LCD's are past.
>
> We've been through this, Stephen, where you pull out your
> highly misleading "research paper"

Papers. From several sources. With actual measurements.

> and make highly misleading
> claims based on misleading information.

And you come back and say, "Everybody knows..." with no data (or
misleading data) to support your assertions. Is your lack of
information less "misleading" than my information?

> The bottom line? Virtually no professional graphic shops use
> LCDs. Why?

Because they rely on experience and conventional wisdom, rather than
measured performance of modern equipment. I am becoming increasingly
convinced of this, as I hear the arguments supporting the "LCDs are
inferior" assertion.

> Because any serious attempt at color correcting
> on con/prosumer LCDs is an exercise in futility. End of story.

Well, I'm not sure what you mean by "con/prosumer LCDs". To be
specific, RR Donnelly specifies the Apple 20" Cinema Display as
part of their prepress soft proofing system. Are they ignorant about
display calibration?

In short, you are totally convinced of your claims, you don't have the
data to back up your claim of inferior gamut, and you deem any
evidence to the contrary "misleading".

--
-Stephen H. Westin
Any information or opinions in this message are mine: they do not
represent the position of Cornell University or any of its sponsors.
Anonymous
a b U Graphics card
September 28, 2004 10:10:43 PM

Archived from groups: comp.graphics.algorithms,comp.graphics.visualization,comp.sys.ibm.pc.hardware.video,rec.photo.digital,sci.image.processing (More info?)

"Rick" <me@privacy.net> wrote in message
news:2rrn0cF1dcknkU1@uni-berlin.de...
> We've been through this, Stephen, where you pull out your
> highly misleading "research paper" and make highly misleading
> claims based on misleading information.
>
> The bottom line? Virtually no professional graphic shops use
> LCDs. Why? Because any serious attempt at color correcting
> on con/prosumer LCDs is an exercise in futility. End of story.

Well, YOU made the claim that a given CRT monitor
"outgamuts" an LCD. Stephen quite rightly asked you to
justify that claim by describing the gamut of the monitor in
question in quantitative terms. I'd also like to see that, and
am willing to bet that you can't provide numbers that support
that specific claim. Whether or not "any serious attempt at
color correcting... is an exercise in futility" is not relevant to
the claims you've made. (In other words, you may be right
in that broad statement, at least for most current monitors,
but not for the reasons you stated.)

So let's see your numbers. End of story.

Bob M.
September 28, 2004 10:10:44 PM

Archived from groups: comp.graphics.algorithms,comp.graphics.visualization,comp.sys.ibm.pc.hardware.video,rec.photo.digital,sci.image.processing (More info?)

"Bob Myers" <nospamplease@address.invalid> wrote in message news:D Oh6d.11857$JM5.6885@news.cpqcorp.net...
>
> "Rick" <me@privacy.net> wrote in message
> news:2rrn0cF1dcknkU1@uni-berlin.de...
> > We've been through this, Stephen, where you pull out your
> > highly misleading "research paper" and make highly misleading
> > claims based on misleading information.
> >
> > The bottom line? Virtually no professional graphic shops use
> > LCDs. Why? Because any serious attempt at color correcting
> > on con/prosumer LCDs is an exercise in futility. End of story.
>
> Well, YOU made the claim that a given CRT monitor
> "outgamuts" an LCD. Stephen quite rightly asked you to
> justify that claim by describing the gamut of the monitor in
> question in quantitative terms. I'd also like to see that, and
> am willing to bet that you can't provide numbers that support
> that specific claim. Whether or not "any serious attempt at
> color correcting... is an exercise in futility" is not relevant to
> the claims you've made. (In other words, you may be right
> in that broad statement, at least for most current monitors,
> but not for the reasons you stated.)
>
> So let's see your numbers. End of story.

This debate is recurring. The last one was not long ago. The
numbers in Stephen's reference have been discussed over and
over, with the same conclusion every time. The reference's
numbers show (correctly) that CRTs have orders of magnitude
more dynamic range, especially for near blacks, then it proceeds
to claim that this isn't an advantage, because of "typical office
lighting conditions" -- which is completely irrelevant to the issue.

Those who claim LCDs have anywhere near the same gamut as
a decent CRT are generally the same people who've never even
heard of a light hood. I invite you to look up these previous
threads in Google's Usenet archive, e.g. http://tinyurl.com/623mb

Rick
Anonymous
a b U Graphics card
September 29, 2004 2:42:29 AM

Archived from groups: comp.graphics.algorithms,comp.graphics.visualization,comp.sys.ibm.pc.hardware.video,rec.photo.digital,sci.image.processing (More info?)

"Rick" <me@privacy.net> writes:

> "Bob Myers" <nospamplease@address.invalid> wrote in message news:D Oh6d.11857$JM5.6885@news.cpqcorp.net...
> >
> > "Rick" <me@privacy.net> wrote in message
> > news:2rrn0cF1dcknkU1@uni-berlin.de...
> > > We've been through this, Stephen, where you pull out your
> > > highly misleading "research paper" and make highly misleading
> > > claims based on misleading information.
> > >
> > > The bottom line? Virtually no professional graphic shops use
> > > LCDs. Why? Because any serious attempt at color correcting
> > > on con/prosumer LCDs is an exercise in futility. End of story.
> >
> > Well, YOU made the claim that a given CRT monitor
> > "outgamuts" an LCD. Stephen quite rightly asked you to
> > justify that claim by describing the gamut of the monitor in
> > question in quantitative terms. I'd also like to see that, and
> > am willing to bet that you can't provide numbers that support
> > that specific claim. Whether or not "any serious attempt at
> > color correcting... is an exercise in futility" is not relevant to
> > the claims you've made. (In other words, you may be right
> > in that broad statement, at least for most current monitors,
> > but not for the reasons you stated.)
> >
> > So let's see your numbers. End of story.
>
> This debate is recurring. The last one was not long ago. The
> numbers in Stephen's reference have been discussed over and
> over, with the same conclusion every time. The reference's
> numbers show (correctly) that CRTs have orders of magnitude
> more dynamic range, especially for near blacks, then it proceeds
> to claim that this isn't an advantage, because of "typical office
> lighting conditions" -- which is completely irrelevant to the issue.
>
> Those who claim LCDs have anywhere near the same gamut as
> a decent CRT are generally the same people who've never even
> heard of a light hood. I invite you to look up these previous
> threads in Google's Usenet archive, e.g. http://tinyurl.com/623mb
>
> Rick
>
>
"Rick" <me@privacy.net> writes:

> "Bob Myers" <nospamplease@address.invalid> wrote in message news:D Oh6d.11857$JM5.6885@news.cpqcorp.net...
> >
> > "Rick" <me@privacy.net> wrote in message
> > news:2rrn0cF1dcknkU1@uni-berlin.de...
> > > We've been through this, Stephen, where you pull out your
> > > highly misleading "research paper" and make highly misleading
> > > claims based on misleading information.
> > >
> > > The bottom line? Virtually no professional graphic shops use
> > > LCDs. Why? Because any serious attempt at color correcting
> > > on con/prosumer LCDs is an exercise in futility. End of story.
> >
> > Well, YOU made the claim that a given CRT monitor
> > "outgamuts" an LCD. Stephen quite rightly asked you to
> > justify that claim by describing the gamut of the monitor in
> > question in quantitative terms. I'd also like to see that, and
> > am willing to bet that you can't provide numbers that support
> > that specific claim. Whether or not "any serious attempt at
> > color correcting... is an exercise in futility" is not relevant to
> > the claims you've made. (In other words, you may be right
> > in that broad statement, at least for most current monitors,
> > but not for the reasons you stated.)
> >
> > So let's see your numbers. End of story.
>
> This debate is recurring. The last one was not long ago. The
> numbers in Stephen's reference have been discussed over and
> over, with the same conclusion every time. The reference's
> numbers show (correctly) that CRTs have orders of magnitude
> more dynamic range, especially for near blacks,

First, a CRT with a totally black screen will be much darker than
an LCD with the same image. Unfortunately, that gets a lot brighter
if you actually display anything useful on the screens. Orders of
magnitude brighter, so that the dynamic range of a CRT with reasonable
image content isn't dramatically better than that of an LCD. As I recall,
the figure was around 4000:1 range for black screen vs. white screen,
but only about 350:1 when the majority of the screen is displaying
middle gray.

Second, "dynamic range" is the ratio between white and black, so
I don't know what "more dynamic range, especially for near blacks"
can possibly mean.

> then it proceeds
> to claim that this isn't an advantage, because of "typical office
> lighting conditions" -- which is completely irrelevant to the issue.

Because, of course, you only use your CRT in a photographic darkroom..

> Those who claim LCDs have anywhere near the same gamut as
> a decent CRT are generally the same people who've

... actually measured them.

> never even
> heard of a light hood.

Oh do please explain how the color gamut of a display is
strongly affected by stray light.

As Bob pointed out, you may not understand what the term "display
gamut" means. It primarily refers to the chromaticities produced; as
Bob also pointed out, there doesn't seem to be an advantage of CRT's
over the best LCD's these days.

> I invite you to look up these previous
> threads in Google's Usenet archive, e.g. http://tinyurl.com/623mb

Hmm. You might actually want to read them yourself.

I recall my reference to the Munsell Color Science Lab at RIT and your
vehement misinterpretation as meaning the Munsell Labs subsidiary of
GretagMacbeth. I remember my quotes from their director, and your
references to "most professionals", whoever they may be, and "almost
everyone who has tried it". I recall posting links to various
measurements, and in fact measuring my own CRT, and your never
responding once with any sort of quantitative assessment.

As far as I can tell, you don't know much about color science, don't
know the meaning of the terms you throw around, and would rather
follow "conventional wisdom" than actually find out the truth of the
matter.

--
-Stephen H. Westin
Any information or opinions in this message are mine: they do not
represent the position of Cornell University or any of its sponsors.
Anonymous
a b U Graphics card
September 29, 2004 3:12:07 AM

Archived from groups: comp.graphics.algorithms,comp.graphics.visualization,comp.sys.ibm.pc.hardware.video,rec.photo.digital,sci.image.processing (More info?)

"Rick" <me@privacy.net> wrote in message
news:2ru2ekF1f2o25U1@uni-berlin.de...
> > So let's see your numbers. End of story.
>
> This debate is recurring. The last one was not long ago. The
> numbers in Stephen's reference have been discussed over and
> over, with the same conclusion every time. The reference's
> numbers show (correctly) that CRTs have orders of magnitude
> more dynamic range, especially for near blacks, then it proceeds
> to claim that this isn't an advantage, because of "typical office
> lighting conditions" -- which is completely irrelevant to the issue.

Sorry, but the proposition you made wasn't about
dynamic range, it was about gamut. You've been asked
at least twice now (well, three times, counting this) to
provide values that would back up YOUR claim of a wider
gamut for CRTs vs. LCDs, and we're still waiting. Further,
the notion of "orders of magnitude" more dynamic range is
clear nonsense in the first place - even if that WERE the
subject under discussion here.


> Those who claim LCDs have anywhere near the same gamut as
> a decent CRT are generally the same people who've never even
> heard of a light hood.

Possibly in your experience, but also irrelevant here. I
personally have over twenty years' experience testing
displays, including both CRTs and LCDs, and have very
recent test data (from products currently on the market,
of both types) which shows that the claim of wider gamut
for the CRT is nonsense. It was certainly true in the past,
but has not been true for some time now.

So again - I would invite YOU to either provide some
numbers, or tell us just what oddball definition of the term
"gamut" you're using here.

Bob M.
September 29, 2004 3:12:08 AM

Archived from groups: comp.graphics.algorithms,comp.graphics.visualization,comp.sys.ibm.pc.hardware.video,rec.photo.digital,sci.image.processing (More info?)

"Bob Myers" <nospamplease@address.invalid> wrote in message news:bdm6d.11931$X36.6569@news.cpqcorp.net...
>
> "Rick" <me@privacy.net> wrote in message
> news:2ru2ekF1f2o25U1@uni-berlin.de...
> > > So let's see your numbers. End of story.
> >
> > This debate is recurring. The last one was not long ago. The
> > numbers in Stephen's reference have been discussed over and
> > over, with the same conclusion every time. The reference's
> > numbers show (correctly) that CRTs have orders of magnitude
> > more dynamic range, especially for near blacks, then it proceeds
> > to claim that this isn't an advantage, because of "typical office
> > lighting conditions" -- which is completely irrelevant to the issue.
>
> Sorry, but the proposition you made wasn't about
> dynamic range, it was about gamut. You've been asked
> at least twice now (well, three times, counting this) to
> provide values that would back up YOUR claim of a wider
> gamut for CRTs vs. LCDs, and we're still waiting. Further,
> the notion of "orders of magnitude" more dynamic range is
> clear nonsense in the first place - even if that WERE the
> subject under discussion here.

I've referenced the thread that gives these numbers. It's in
Stephen's own "research paper". You trimmed that reference,
and now are claiming one haven't been given. So you're either
lazy, stupid or (most likely) just another pathetic troll like
Stephen.

Look, I learned a long time ago there no accounting for
intelligence. If you believe LCDs have an equal or greater color
gamut to CRTs, then by all means use them. You'll just be one
more moron over which professionals will have a competitive
advantage.

Rick
Anonymous
a b U Graphics card
September 29, 2004 5:55:30 AM

Archived from groups: comp.graphics.algorithms,comp.graphics.visualization,comp.sys.ibm.pc.hardware.video,rec.photo.digital,sci.image.processing (More info?)

Actually, I believe the on-axis viewing of LCD's can be as good if not
better than a CRT. The problem with LCD's are that they tend to suffer
chroma and luminance shifts when being viewed off axis (viewing angle
issues). Apple Cinema displays have come a long way in addressing this, but
it's still not fully addressed. One particular problem here is that when
you're viewing a very large display close-up, there is a considerable change
in your effective viewing angle across the screen. All of this leads to
difficulties where absolute color-accuracy is needed.

James

"Rick" <me@privacy.net> wrote in message
news:2rrn0cF1dcknkU1@uni-berlin.de...
> "Stephen H. Westin" <westin*nospam@graphics.cornell.edu> wrote in message
news:s0acvbmkrk.fsf@diesel.graphics.cornell.edu...
> > "Rick" <me@privacy.net> writes:
> >
> > > "Bob Myers" <nospamplease@address.invalid> wrote in message
news:Kw15d.11687$MS.7082@news.cpqcorp.net...
> > > >
> > > > "Ron W. Silvas" <contact@silvasdigital.com> wrote in message
> > > > news:c516aeb9.0409241202.6a4f5b6c@posting.google.com...
> > > > > I've found that 24-bit artifacts are quite demonstratable on both
CRTs
> > > > > and LCDs, alike, (as can be experienced with the previously
mentioned
> > > > > tech demo) but I believe that, if anything, they would be more
> > > > > noticeable on CRTs because the higher dynamic range of a CRT means
that
> > > > > an 8-bit color channel's 256 intensity/brightness levels have that
much
> > > > > more perceptual space to cover, right?
> > > >
> > > > I've been following this thread with interest, but a couple of
> > > > comments seem appropriate at this point.
> > > >
> > > > First - what "higher dynamic range" of the CRT? Neither the
> > > > color gamut or the contrast of the typical CRT display is
> > > > much different that what can be obtained with the LCD.
> > >
> > > Nonsense. The backlight technology used in LCDs (at least
> > > those in the con/prosumer range) precludes the possibility that
> > > they can match the gamut of a decent CRT. E.g. a $700
> > > Mitsubishi 2070 easily outgamuts a $1300 Apple Cinema
> > > Display.
> >
> > Really? Where did you find this out? Do you have the respective primary
> > chromaticities handy?
> >
> > > > What I think the problem here really is, is a difference in the
> > > > response curves of the two technologies. CRTs have a very
> > > > nice (perceptually) "gamma" sort of response, whereas LCDs
> > > > have a perceptually-nastier "S-shaped" response that cannot
> > > > adequately be compensated for with only 8 bits per channel,
> > > > not if you still intend to have 8 bit/channel of perceptually linear
> > > > intensity control. The solution here is greater dynamic range
> > > > (bit depth) at the panel (i.e., at the driver level), to permit
> > > > compensation for the panel's response and thus present a
> > > > "CRT-like" 8-bit input. Fortunately, we ARE starting to see
> > > > 10-bit LCD drivers entering the market.
> > >
> > > More nonsense. No amount of compensation will overcome
> > > the limitations of LCD's backlight technology. One has the
> > > choice of losing near blacks altogether, or settling for a
> > > constant and muddy bluish or grayish glow instead of black.
> >
> > In any reasonable lighting level, a good LCD will be at least
> > competitive in dynamic range with any CRT. The days of all CRT's being
> > better than all LCD's are past.
>
> We've been through this, Stephen, where you pull out your
> highly misleading "research paper" and make highly misleading
> claims based on misleading information.
>
> The bottom line? Virtually no professional graphic shops use
> LCDs. Why? Because any serious attempt at color correcting
> on con/prosumer LCDs is an exercise in futility. End of story.
>
> Rick
>
>
Anonymous
a b U Graphics card
September 29, 2004 8:09:50 AM

Archived from groups: comp.graphics.algorithms,comp.graphics.visualization,comp.sys.ibm.pc.hardware.video,rec.photo.digital,sci.image.processing (More info?)

"Rick" <me@privacy.net> wrote in message
news:2rudfuF1en4inU1@uni-berlin.de...
> > Sorry, but the proposition you made wasn't about
> > dynamic range, it was about gamut. You've been asked
> > at least twice now (well, three times, counting this) to
> > provide values that would back up YOUR claim of a wider
> > gamut for CRTs vs. LCDs, and we're still waiting. Further,
> > the notion of "orders of magnitude" more dynamic range is
> > clear nonsense in the first place - even if that WERE the
> > subject under discussion here.
>
> I've referenced the thread that gives these numbers.

Right...and I perused that thread as far as I needed to,
to see that it was long on opinion and short on objective
data. Since I already have data from any number of sources,
including direct personal experience in the test lab, which
confirm my assertions regarding display gamut, it's not
my job to dig through that pile in search of the evidence that
YOU need to support YOUR assertion. I (and Stephen,
for that matter, at least as I understand his comments to
date - but I'll let him speak for himself) am asking that
you supply exactly six pairs of numbers - giving the
measured coordinates of the three primaries for
representative samples of the two technologies. I've already
provided a set that I believe is very representative; if
you don't have contradictory data, then I guess we'll just
have to take the matter as settled, won't we?


> It's in
> Stephen's own "research paper". You trimmed that reference,
> and now are claiming one haven't been given.

No, I have made no such claim. I have said that YOU
have given no values which support YOUR assertion,
here. The truth of that statement is evident from a simple
review of the current thread. Which would then lead one
to believe that you are, in fact,

> either
> lazy, stupid or (most likely) just another pathetic troll

> Look, I learned a long time ago there no accounting for
> intelligence. If you believe LCDs have an equal or greater color
> gamut to CRTs, then by all means use them.

Not only do I believe this - at least, under the commonly-
accepted meaning of the term "gamut" (God only knows
what you mean by that term) - but I have (and have presented
here) data which demonstrates this. It is up to you to show
contradictory evidence, or to retract your claim. It's rather
funny (and more than a little pathetic) that you're trying to
label the only people to actually present data here as "lazy"
when you yourself are unwilling to do so. What's the matter,
is it just too difficult to type in those twelve values?


Bob M.
Anonymous
a b U Graphics card
September 29, 2004 2:36:56 PM

Archived from groups: comp.graphics.algorithms,comp.graphics.visualization,comp.sys.ibm.pc.hardware.video,rec.photo.digital,sci.image.processing (More info?)

Bob Myers wrote:
> "Rick" <me@privacy.net> wrote in message
> news:2rrn0cF1dcknkU1@uni-berlin.de...
>
>>We've been through this, Stephen, where you pull out your
>>highly misleading "research paper" and make highly misleading
>>claims based on misleading information.
>>
>>The bottom line? Virtually no professional graphic shops use
>>LCDs. Why? Because any serious attempt at color correcting
>>on con/prosumer LCDs is an exercise in futility. End of story.
>
>
> Well, YOU made the claim that a given CRT monitor
> "outgamuts" an LCD. Stephen quite rightly asked you to
> justify that claim by describing the gamut of the monitor in
> question in quantitative terms. I'd also like to see that, and
> am willing to bet that you can't provide numbers that support
> that specific claim. Whether or not "any serious attempt at
> color correcting... is an exercise in futility" is not relevant to
> the claims you've made. (In other words, you may be right
> in that broad statement, at least for most current monitors,
> but not for the reasons you stated.)
>
> So let's see your numbers. End of story.
>
> Bob M.

The colour gamut depends on the colour filters as well as the backlight.
Just to add some data to the mix: I recently measured a prototype EIZO
CG LCD (which was claimed to have an AdobeRGB gamut), with a Minolta
CS1000, in our lab. Set up to a nominal 200cd/m2 and D65 white point,
room blacked out:
x y Luminance (cd/m2)
White 0.3141 0.3133 119.6
Red 0.643 0.3328 38.42
Green 0.2058 0.7147 72.49
Blue 0.1464 0.0655 10.89
Black 0.3043 0.34 0.63

These data agree closely with the target AdobeRGB (1998) primaries, and thus
the gamut is considerably larger than a CRT using EBU or similar
phosphors as primaries.

I think you will see professional prepress graphics users increasingly
adopting LCDs as price/performance improves.

In the above measurements, the screen was displaying a set of mixed
colour patches so the black point includes some flare light within the
face plate. As an aside, claims regarding dynamic range depend heavily
on the instrumentation used to measure the black - relatively few
instruments can get down even to 1 cd/m2.

--
Phil Green
Colour Imaging Group
London College of Communication
Elephant and Castle, London SE1 6SB
Tel: +44 020 7514 6759 Fax: +44 020 7514 6772
http://www.digitalcolour.org
September 29, 2004 3:17:49 PM

Archived from groups: comp.graphics.algorithms,comp.graphics.visualization,comp.sys.ibm.pc.hardware.video,rec.photo.digital,sci.image.processing (More info?)

"Phil Green" <green@colourspace.demon.co.uk> wrote in message news:415A8238.5080308@colourspace.demon.co.uk...
> The colour gamut depends on the colour filters as well as the backlight.
> Just to add some data to the mix: I recently measured a prototype EIZO
> CG LCD (which was claimed to have an AdobeRGB gamut), with a Minolta
> CS1000, in our lab. Set up to a nominal 200cd/m2 and D65 white point,
> room blacked out:
> x y Luminance (cd/m2)
> White 0.3141 0.3133 119.6
> Red 0.643 0.3328 38.42
> Green 0.2058 0.7147 72.49
> Blue 0.1464 0.0655 10.89
> Black 0.3043 0.34 0.63
>
> These data agree closely with the target AdobeRGB (1998) primaries, and thus
> the gamut is considerably larger than a CRT using EBU or similar
> phosphors as primaries.
>
> I think you will see professional prepress graphics users increasingly
> adopting LCDs as price/performance improves.

At $2800 for the 21" model, there's a lot of "improvement"
to go. Personally I'd rather have FOUR 22" Mitsu 2070's
for the same money.

Rick
Anonymous
a b U Graphics card
September 29, 2004 4:38:43 PM

Archived from groups: comp.graphics.algorithms,comp.graphics.visualization,comp.sys.ibm.pc.hardware.video,rec.photo.digital,sci.image.processing (More info?)

[Followups set back to rec.photo.digital only - please don't help this
troll spray this disinformation all over Usenet.]

Kibo informs me that westin*nospam@graphics.cornell.edu (Stephen H.
Westin) stated that:

>"Rick" <me@privacy.net> writes:
>> More nonsense. No amount of compensation will overcome
>> the limitations of LCD's backlight technology. One has the
>> choice of losing near blacks altogether, or settling for a
>> constant and muddy bluish or grayish glow instead of black.
>
>In any reasonable lighting level, a good LCD will be at least
>competitive in dynamic range with any CRT.

I (& others) debunked this claim of yours the last you brought it up
here. The only time that statement is true is under bright office
lighting, where the reflected glare on CRTs reduces their effective
contrast down to below that of LCDs under the same lighting. Anyone
who's serious about colour work operates under subdued lighting to
prevent that effect.

> The days of all CRT's being
>better than all LCD's are past.

As Rick pointed out, the limitations of LCD backlighting currently make
LCDs greatly inferior to CRTs WRT to black levels & shadow detail. I
don't know of any LCD on the market that can match even a generic CRT in
that area.

--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------
Anonymous
a b U Graphics card
September 29, 2004 4:38:44 PM

Archived from groups: rec.photo.digital,comp.sys.ibm.pc.hardware.video (More info?)

(comp.sys.ibm.pc.hardware.video added back in; please leave it,
as this is the group in which I normally see these discussions, and
this is quite a bit more relevant to a discussion of electronic display
technology - nominally the field covered in that group - than in
digital photography per se.)

<usenet@imagenoir.com> wrote in message
news:ei7kl01fidj50kuqv35rth5784vjr3h9mn@4ax.com...
>> As Rick pointed out, the limitations of LCD backlighting currently make
> LCDs greatly inferior to CRTs WRT to black levels & shadow detail. I
> don't know of any LCD on the market that can match even a generic CRT in
> that area.

Unfortunately, no one seems to be able to describe precisely
what these "limitations of LCD backlighting" ARE. Nor do these
factors ("black level" and "shadow detail") have anything to do
with color gamut, which was the original point of disagreement.

However, since you've brought these items up, let's dispose of
them as well.

It is absolutely correct that the LCD panels as typically used in
current monitor products provide a higher luminance at the
"black" level than a properly-adjusted CRT. However, this
is not necessarily indicative of an inherent inability of the LCD
to match the CRT's performance in this area. As they have
been driven by today's marketing expectations, LCD monitor
panels also offer a very significantly higher white luminance
(as much as 3-4X) over typical CRT monitor products.
Since the LCD does operate as a "light valve" - and it is
impossible to completely block the light from the backlight
- it is also correct to say that the LCD will, in practical terms,
never provide an absolutely zero-luminance black. But then,
neither does the CRT when properly adjusted. A CRT
monitor's black level must be set very slightly above zero,
or else the CRT cutoff point would have to be constantly
adjusted (the black would tend to slip below blanking,
making the lower end of the luminance range very non-linear).
Typical real-world values for the black-level luminance will
be in the range of 0.05-0.5 cd/m^2 (most often toward the
upper end of this range), vs. somewhere around 1 cd/m^2 or
so for a typical monitor LCD. But since the LCD's white
these days is up around 350-400 cd/m^2 (vs. something
more like 100 for the CRT), simply cutting down the backlight
output (or, in a more brute-force approach, filtering the LCD)
would bring its black and white values down to something
very comparable to the CRT. That few products do this
says much more about the demand in the market than it does
anything at all about inherent differences in the technology.

In terms of the "shadow detail" (i.e., the ability to
discriminate "shades of gray" at the low end of the luminance
range, we get back to differences in the response
characteristics of the two technologies - which, if you'll
look back over this thread, was my point in the first
place.

Bob M.
Anonymous
a b U Graphics card
September 29, 2004 4:42:30 PM

Archived from groups: comp.graphics.algorithms,comp.graphics.visualization,comp.sys.ibm.pc.hardware.video,rec.photo.digital,sci.image.processing (More info?)

[Followups set to rec.photo.digital only - if anyone else wishes to
respond to this troll, please snip out the extra groups as well.]

Kibo informs me that westin*nospam@graphics.cornell.edu (Stephen H.
Westin) stated that:

>"Rick" <me@privacy.net> writes:
>> > In any reasonable lighting level, a good LCD will be at least
>> > competitive in dynamic range with any CRT. The days of all CRT's being
>> > better than all LCD's are past.
>>
>> We've been through this, Stephen, where you pull out your
>> highly misleading "research paper"
>
>Papers. From several sources.

Bull.

> With actual measurements.

Taken under typical office lighting, as I discovered when I read the
paper you'd been quoting. Nobody doing serious colour/photographic work
operates under office lighting.

--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------
Anonymous
a b U Graphics card
September 29, 2004 4:42:31 PM

Archived from groups: comp.sys.ibm.pc.hardware.video (More info?)

<usenet@imagenoir.com> wrote in message
news:228kl0h7nd5rleui5i7q9mk80g3lj9pbtr@4ax.com...
> > With actual measurements.
>
> Taken under typical office lighting, as I discovered when I read the
> paper you'd been quoting.

I won't say anything about the "paper you've been
quoting", but I will note that all measurements I've been
speaking of in this thread were made under both dark
ambient (per the procedures of the VESA Flat Panel
Display Measurement standard, version 2.0) and, for
comparison purposes under "office" conditions (as the
monitors I test are generally sold for use in office
environments). So I am both very familiar with the
differences in test results between the two environments,
and have extensive test data taken under both sets of
conditions.

> Nobody doing serious colour/photographic work
> operates under office lighting.

While I understand the perspective you're coming
from in this statement, it is not altogether correct. For
example, those who are doing work in color graphics
which are ultimately expected to be viewed by average
computer users in typical environments (say, web page
design) are well-advised to view their products not only
in their preferred low-ambient environment, but also
under the conditions that end user of the product will
be experiencing.

Bob M.
Anonymous
a b U Graphics card
September 29, 2004 4:53:48 PM

Archived from groups: comp.graphics.algorithms,comp.graphics.visualization,comp.sys.ibm.pc.hardware.video,rec.photo.digital,sci.image.processing (More info?)

[Followups set to rec.photo.digital only]

Kibo informs me that contact@silvasdigital.com (Ron W. Silvas) stated
that:

>"Bob Myers" <nospamplease@address.invalid> wrote in message news:<Kw15d.11687$MS.7082@news.cpqcorp.net>...
>> "Ron W. Silvas" <contact@silvasdigital.com> wrote in message
>> news:c516aeb9.0409241202.6a4f5b6c@posting.google.com...
>> > I've found that 24-bit artifacts are quite demonstratable on both CRTs
>> > and LCDs, alike, (as can be experienced with the previously mentioned
>> > tech demo) but I believe that, if anything, they would be more
>> > noticeable on CRTs because the higher dynamic range of a CRT means that
>> > an 8-bit color channel's 256 intensity/brightness levels have that much
>> > more perceptual space to cover, right?
>>
>> I've been following this thread with interest, but a couple of
>> comments seem appropriate at this point.
>>
>> First - what "higher dynamic range" of the CRT? Neither the
>> color gamut or the contrast of the typical CRT display is
>> much different that what can be obtained with the LCD.
>> What I think the problem here really is, is a difference in the
>> response curves of the two technologies. CRTs have a very
>> nice (perceptually) "gamma" sort of response, whereas LCDs
>> have a perceptually-nastier "S-shaped" response that cannot
>> adequately be compensated for with only 8 bits per channel,
>> not if you still intend to have 8 bit/channel of perceptually linear
>> intensity control. The solution here is greater dynamic range
>> (bit depth) at the panel (i.e., at the driver level), to permit
>> compensation for the panel's response and thus present a
>> "CRT-like" 8-bit input. Fortunately, we ARE starting to see
>> 10-bit LCD drivers entering the market.
>>
>> Bob M.
>
>Hi, Mr. Myers.
>
>It might be time for me to exit from this branch of the
>discussion, as I am admittedly not very knowledgeable about the
>areas being discussed (dynamic ranges, contrast ratios,
>hardware behavioral differences between LCD and CRT
>technologies, etc.). =)
>
>My earlier comment . . .
>
>> > "I believe that, if anything, they would be more noticeable
>> > on CRTs because the higher dynamic range of a CRT . . . "
>
>. . . was a jump to a conclusion on my part–

But a correct one, in most cases. ;) 

>I should have asked
>Mr. Westin if he could explain to me his comment about the
>different dynamic ranges before I commented on that. Totally
>my mistake.

Mr Westin is mistaken in his comments anyway.

> o 30-bit color's >1000 intensity levels per channel *is*
> finally enough.
> o 30-bit color display is desirable.
> o 30-bit color display on common 24-bit hardware would be a
> nice bonus, and . . .
>
>It works. On CRTs and LCDs, alike. No special hardware
>requirements. No special OS support needed.

Indeed. Did you know that the Matrox Parhelia cards already have true 30
bit resolution in hardware?
<http://www.matrox.com/mga/workstation/digital_design/pr...;

--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------
Anonymous
a b U Graphics card
September 29, 2004 4:53:49 PM

Archived from groups: comp.graphics.algorithms,comp.graphics.visualization,comp.sys.ibm.pc.hardware.video,rec.photo.digital,sci.image.processing (More info?)

Hi, imagenoir person. =)

usenet@imagenoir.com wrote in message news:<7g8kl0tp7n8n6epenin7uid5ktfnr2tlif@4ax.com>...
> "Ron W. Silvas" <contact@silvasdigital.com> wrote:
> >It might be time for me to exit from this branch of the
> >discussion, as I am admittedly not very knowledgeable about the
> >areas being discussed (dynamic ranges, contrast ratios,
> >hardware behavioral differences between LCD and CRT
> >technologies, etc.). =)
> >
> >My earlier comment . . .
> >
> >> > "I believe that, if anything, they would be more noticeable
> >> > on CRTs because the higher dynamic range of a CRT . . . "
> >
> >. . . was a jump to a conclusion on my part . . .
>
> But a correct one, in most cases. ;) 
> . . .
> Mr Westin is mistaken in his comments anyway.

Yeah, I really wouldn't know--This project was mostly concerned
with color depth extension.

> > o 30-bit color's >1000 intensity levels per channel *is*
> > finally enough.
> > o 30-bit color display is desirable.
> > o 30-bit color display on common 24-bit hardware would be a
> > nice bonus, and . . .
> >
> >It works. On CRTs and LCDs, alike. No special hardware
> >requirements. No special OS support needed.
>
> Indeed. Did you know that the Matrox Parhelia cards already
> have true 30 bit resolution in hardware?

Yes, thank you for making sure, though. I actually have a
Matrox P650, which is like the baby brother of the Parhelia--
It has their 30-bit "GigaColor", also. But, unfortunately . . .
o I don't believe there's currently much OS or software
support for 30-bit color. (Outside of Windows's
DirectX 8+, anyway?)
o No 30-bit color on nearly all of today's LCDs, as far as
I can tell.

But with the synthesized 30-bit color that this project dealt
with, none of that really matters, right? =)

Thank you for checking about the Matrox deal, though,
- Ron
Anonymous
a b U Graphics card
September 29, 2004 9:39:14 PM

Archived from groups: comp.graphics.algorithms,comp.graphics.visualization,comp.sys.ibm.pc.hardware.video,rec.photo.digital,sci.image.processing (More info?)

contact@silvasdigital.com (Ron W. Silvas) wrote in message news:<c516aeb9.0409241002.96a8038@posting.google.com>...
> "Rick" <me@privacy.net> wrote in message news:<2ri1d1F1b8f8pU1@uni-berlin.de>...
> > Ron, have you written an API for extended-bit printer
> > drivers? Windows is limited to 24-bit output, and without
> > the aforementioned API your technology is of very limited
> > use (at least under Windows).
>
> Hi, Rick.
>
> No, I haven't written any sort of print driver.
>
> And, like you, I suspect that visualizing in color depths beyond what
> your target output device is capable of producing might not be the best
> idea, but . . .
>
> Paper is by no means the only target medium out there these days,
> right? The video game and multimedia industry produces content for
> display on computer monitors and televisions, the motion picture
> industry--including their animation and special effects studios--
> produce content for film and 30-bit digital projection, and I believe
> medical imaging usually requires greater than 24-bit color fidelity (or
> greater than 8-bit grayscale, etc.).

You know, the more I thought about this, I don't see any problem
at all with visualizing work destined for 24-bit output in 30-bit
color. This seems like a totally healthy workflow, to me:
o Capture/Create and Work in High Fidelity Color (48-bit, etc.)
o Display in 30-bit Color
o Appropriately Convert (probably via dithering) to 24-bit
Target for Output

You don't need print driver support for that--Photoshop will
optionally dither when converting from 16-bit channels to 8-bit.
I'm not sure if it will automatically do this when a 48-bit image
is sent to print--I suspect--but, in either case, you can still
get your dithered 24-bit output.

Does that seem right?
- Ron
Anonymous
a b U Graphics card
September 30, 2004 6:13:54 AM

Archived from groups: comp.graphics.algorithms,comp.graphics.visualization,comp.sys.ibm.pc.hardware.video,rec.photo.digital,sci.image.processing (More info?)

"Phil Green" <green@colourspace.demon.co.uk> wrote in message
news:415A8238.5080308@colourspace.demon.co.uk...
> The colour gamut depends on the colour filters as well as the backlight.
> Just to add some data to the mix: I recently measured a prototype EIZO
> CG LCD (which was claimed to have an AdobeRGB gamut), with a Minolta
> CS1000, in our lab. Set up to a nominal 200cd/m2 and D65 white point,
> room blacked out:
> x y Luminance (cd/m2)
> White 0.3141 0.3133 119.6
> Red 0.643 0.3328 38.42
> Green 0.2058 0.7147 72.49
> Blue 0.1464 0.0655 10.89
> Black 0.3043 0.34 0.63

Thank you very much for the numbers, Phil; at least
SOMEONE else out there has actually measured these
things. I haven't tested that particular product, but these
values are certainly in line with what I would expect from
a current high-end product (which is, of course, exactly
what the oft-referenced "professional graphics" sort
of user would actually be using). That's a pretty
impressive green. by the way!

Still no data from the "CRTs 'outgamut' LCDs"
crowd? Sigh....


> I think you will see professional prepress graphics users increasingly
> adopting LCDs as price/performance improves.

Agreed; in fact, I've recently been working very closely
with a number of customers of this category, and I
would say that the above chageover is already well on
the way.


> In the above measurements, the screen was displaying a set of mixed
> colour patches so the black point includes some flare light within the
> face plate. As an aside, claims regarding dynamic range depend heavily
> on the instrumentation used to measure the black - relatively few
> instruments can get down even to 1 cd/m2.

Also agreed, strongly! In fact, the difficulty of properly
measuring "black" is why just about all published
contrast, etc., claims are to be taken with an enormous
grain of salt as the default position (i.e. until you know
something about the measurement procedures and
equipment used).

Bob M.
>
> --
> Phil Green
> Colour Imaging Group
> London College of Communication
> Elephant and Castle, London SE1 6SB
> Tel: +44 020 7514 6759 Fax: +44 020 7514 6772
> http://www.digitalcolour.org
>
>
Anonymous
a b U Graphics card
September 30, 2004 6:23:06 AM

Archived from groups: comp.graphics.algorithms,comp.graphics.visualization,comp.sys.ibm.pc.hardware.video,rec.photo.digital,sci.image.processing (More info?)

"Rick" <me@privacy.net> wrote in message
news:2s0cikF1drnf5U1@uni-berlin.de...
> At $2800 for the 21" model, there's a lot of "improvement"
> to go. Personally I'd rather have FOUR 22" Mitsu 2070's
> for the same money.

And let me guess - you believe there's something inherently
pricey in the PANEL that Eizo uses in this monitor that
accounts for this pricing?

Bob M.
Anonymous
a b U Graphics card
September 30, 2004 12:33:47 PM

Archived from groups: comp.graphics.algorithms,comp.graphics.visualization,comp.sys.ibm.pc.hardware.video,rec.photo.digital,sci.image.processing (More info?)

"Bob Myers" <nospamplease@address.invalid> wrote:

>> In the above measurements, the screen was displaying a set of mixed
>> colour patches so the black point includes some flare light within the
>> face plate. As an aside, claims regarding dynamic range depend heavily
>> on the instrumentation used to measure the black - relatively few
>> instruments can get down even to 1 cd/m2.
>
>Also agreed, strongly! In fact, the difficulty of properly
>measuring "black" is why just about all published
>contrast, etc., claims are to be taken with an enormous
>grain of salt as the default position (i.e. until you know
>something about the measurement procedures and
>equipment used).

It seems, then, that it would be better to simply calculate the black
level, based on the known properties of the LCD and it's backlight.
Anonymous
a b U Graphics card
September 30, 2004 2:02:14 PM

Archived from groups: comp.graphics.algorithms,comp.graphics.visualization,comp.sys.ibm.pc.hardware.video,rec.photo.digital,sci.image.processing (More info?)

chrisv <chrisv@nospam.invalid> wrote in message news:<pv4gl0pnab89jpj41sdsbsshbq7sqlac7m@4ax.com>...
> contact@silvasdigital.com (Ron W. Silvas) wrote:
>
> >But if your question is . . .
> >"Would anybody see a difference between 24-bit color and 30-bit color?"
> >
> >As Mononen pointed out, the short answer is: Yes they would, but only
> >in some images. (Thanks, Mononen. =)
>
> Maybe, under perfect conditions.
>
> I'd like to see these alleged "some images"...

Hi, Mr. V.

Yeah, when the Matrox Parhelia came out, and then later when I
heard a Studio Ghibli digital animation supervisor talk about
the inadequacies of 24-bit color, I really wanted to see this
stuff for myself, too.

My project's tech demo has a few sample images that allow users
to get a feel for the 24-bit vs. 30-bit difference, and it also
allows users to open their own 48-bit TIFF files, as well. You
can get a feel for if the demo is something you'd be interested
in by checking out its user's manual:
<http://www.silvasdigital.com/xdf/XDF%20Demo%20User's%20Manual.rtf>

And maybe this screenshot:
<http://www.silvasdigital.com/xdf/XDF%20Demo%20Screensho...(800x600).jpg>

You also might find helpful, the "24-bit Color vs. 30-bit Color"
section in the PDF mentioned earlier . . .
<http://www.silvasdigital.com/xdf/XDF%20Project%20Summar...;

Sorry it took me a while to get back to you,
- Ron
Anonymous
a b U Graphics card
September 30, 2004 3:44:23 PM

Archived from groups: comp.graphics.algorithms,comp.graphics.visualization,comp.sys.ibm.pc.hardware.video,rec.photo.digital,sci.image.processing (More info?)

Phil Green <pj.green@cutthisbitlcp.linst.ac.uk> writes:

> Bob Myers wrote:
>
> > Thank you very much for the numbers, Phil; at least
> > SOMEONE else out there has actually measured these
> > things. I haven't tested that particular product, but these
> > values are certainly in line with what I would expect from
> > a current high-end product (which is, of course, exactly
> > what the oft-referenced "professional graphics" sort
> > of user would actually be using). That's a pretty
> > impressive green. by the way!
>
> It certainly looks impressive. They chose these primaries at the
> design stage, based on the fact that a large proportion of people in
> publishing and printing use them in defining a calibrated RGB editing
> space (since the blue-green region encompasses the gamut of offset
> litho printing, unlike the EBU-type primaries).
>
> Without the restriction of rare-earth phosphors, other 'primaries'
> should also be possible.

At SIGGRAPH, NEC/Mitsubishi was showing a prototype LCD with
tricolor LED backlighting. Not only is the white point adjustable,
but the primaries approach the spectrum locus!

<snip>

--
-Stephen H. Westin
Any information or opinions in this message are mine: they do not
represent the position of Cornell University or any of its sponsors.
Anonymous
a b U Graphics card
September 30, 2004 3:47:17 PM

Archived from groups: comp.graphics.algorithms,comp.graphics.visualization,comp.sys.ibm.pc.hardware.video,rec.photo.digital,sci.image.processing (More info?)

Bob Myers wrote:

> Thank you very much for the numbers, Phil; at least
> SOMEONE else out there has actually measured these
> things. I haven't tested that particular product, but these
> values are certainly in line with what I would expect from
> a current high-end product (which is, of course, exactly
> what the oft-referenced "professional graphics" sort
> of user would actually be using). That's a pretty
> impressive green. by the way!

It certainly looks impressive. They chose these primaries at the design
stage, based on the fact that a large proportion of people in publishing
and printing use them in defining a calibrated RGB editing space (since
the blue-green region encompasses the gamut of offset litho printing,
unlike the EBU-type primaries).

Without the restriction of rare-earth phosphors, other 'primaries'
should also be possible.

--
Phil Green
Colour Imaging Group
London College of Communication
Elephant and Castle, London SE1 6SB
Tel: +44 020 7514 6759 Fax: +44 020 7514 6772
http://www.digitalcolour.org
Anonymous
a b U Graphics card
September 30, 2004 3:47:36 PM

Archived from groups: comp.graphics.algorithms,comp.graphics.visualization,comp.sys.ibm.pc.hardware.video,rec.photo.digital,sci.image.processing (More info?)

"Bob Myers" <nospamplease@address.invalid> writes:

> "Rick" <me@privacy.net> wrote in message
> news:2s0cikF1drnf5U1@uni-berlin.de...
> > At $2800 for the 21" model, there's a lot of "improvement"
> > to go. Personally I'd rather have FOUR 22" Mitsu 2070's
> > for the same money.
>
> And let me guess - you believe there's something inherently
> pricey in the PANEL that Eizo uses in this monitor that
> accounts for this pricing?

Well, it's another change in subject. Color gamut turned into
dynamic renge, and now it's price. Rick apparently doesn't know
what a top-quality CRT costs. And presumably the extra cost
goes into ameliorating the deficits inherent in a CRT: geometric
accuracy, long-term stability, etc.

My impression is that at the high end, an LCD will beat a CRT.
But cheap LCD's seem to be much worse than cheap CRT's.

--
-Stephen H. Westin
Any information or opinions in this message are mine: they do not
represent the position of Cornell University or any of its sponsors.
Anonymous
a b U Graphics card
September 30, 2004 9:25:32 PM

Archived from groups: comp.graphics.algorithms,comp.graphics.visualization,comp.sys.ibm.pc.hardware.video,rec.photo.digital,sci.image.processing (More info?)

"Bob Myers" <nospamplease@address.invalid> wrote in message news:<e6K6d.12069$ot7.506@news.cpqcorp.net>...
> "Rick" <me@privacy.net> wrote in message
> news:2s0cikF1drnf5U1@uni-berlin.de...
> > At $2800 for the 21" model, there's a lot of "improvement"
> > to go. Personally I'd rather have FOUR 22" Mitsu 2070's
> > for the same money.
>
> And let me guess - you believe there's something inherently
> pricey in the PANEL that Eizo uses in this monitor that
> accounts for this pricing?
>
> Bob M.


Hi Bob
I'm trying to locate a particular Bob Myers that once sold
a 80 column kit for a Synertek KTM2 keyboard. I'm a collector
of old micro computers and I'm trying to locate information on
this modification.
Thanks
Dwight
Anonymous
a b U Graphics card
October 1, 2004 6:24:05 AM

Archived from groups: comp.graphics.algorithms,comp.graphics.visualization,comp.sys.ibm.pc.hardware.video,rec.photo.digital,sci.image.processing (More info?)

"Stephen H. Westin" <westin*nospam@graphics.cornell.edu> wrote in message
news:s0k6ubu5go.fsf@diesel.graphics.cornell.edu...
> At SIGGRAPH, NEC/Mitsubishi was showing a prototype LCD with
> tricolor LED backlighting. Not only is the white point adjustable,
> but the primaries approach the spectrum locus!

Yes, I've seen that monitor at as couple of display
conferences now, too. Very impressive. Gamut
exceeding the 1953 NTSC space, as I recall, and
bright. At SID this year, LumiLEDs gave a couple
of papers on the technology, and outlined plans for
how it can be applied to monitors, TV, and even
mobile products. Not all with the same devices, of
course, but it's really going to be nice to have an
alternative to CCFLs.

Bob M.
Anonymous
a b U Graphics card
October 1, 2004 6:25:39 AM

Archived from groups: comp.graphics.algorithms,comp.graphics.visualization,comp.sys.ibm.pc.hardware.video,rec.photo.digital,sci.image.processing (More info?)

"chrisv" <chrisv@nospam.invalid> wrote in message
news:vn2ol0d286lqnlm0fd280b41g1mrclhirj@4ax.com...
> It seems, then, that it would be better to simply calculate the black
> level, based on the known properties of the LCD and it's backlight.

Well, yes, but...as a colleague of mine is fond of saying,
in theory, practice and theory give you the same answer -
while in practice, they don't. :-) In short, calculations are
fine, but there's nothing like a good measurement. It's just
that the key part of that in THIS case is that it really is a
GOOD measurement.

Bob M.
Anonymous
a b U Graphics card
October 1, 2004 6:26:29 AM

Archived from groups: comp.graphics.algorithms,comp.graphics.visualization,comp.sys.ibm.pc.hardware.video,rec.photo.digital,sci.image.processing (More info?)

"Stephen H. Westin" <westin*nospam@graphics.cornell.edu> wrote in message
news:s0fz4zu5bb.fsf@diesel.graphics.cornell.edu...
> My impression is that at the high end, an LCD will beat a CRT.
> But cheap LCD's seem to be much worse than cheap CRT's.

I dunno...I've seen some pretty hideous cheap CRTs
in my day. Don't get me started....:-)

Bob M.
Anonymous
a b U Graphics card
October 1, 2004 6:27:25 AM

Archived from groups: comp.graphics.algorithms,comp.graphics.visualization,comp.sys.ibm.pc.hardware.video,rec.photo.digital,sci.image.processing (More info?)

"dwight elvey" <dkelvey@hotmail.com> wrote in message
news:43258753.0409301625.38199336@posting.google.com...
> Hi Bob
> I'm trying to locate a particular Bob Myers that once sold
> a 80 column kit for a Synertek KTM2 keyboard. I'm a collector
> of old micro computers and I'm trying to locate information on
> this modification.

Sorry, Dwight - wasn't me. Good luck finding
him, though.

Bob M.
Anonymous
a b U Graphics card
October 1, 2004 5:13:41 PM

Archived from groups: rec.photo.digital,comp.sys.ibm.pc.hardware.video (More info?)

Kibo informs me that "Bob Myers" <nospamplease@address.invalid> stated
that:

>(comp.sys.ibm.pc.hardware.video added back in; please leave it,
>as this is the group in which I normally see these discussions, and
>this is quite a bit more relevant to a discussion of electronic display
>technology - nominally the field covered in that group - than in
>digital photography per se.)

No problem. I just didn't wish to xpost to a bunch of groups that I
weren't sure were interested in the topic.

><usenet@imagenoir.com> wrote in message
>news:ei7kl01fidj50kuqv35rth5784vjr3h9mn@4ax.com...
>>> As Rick pointed out, the limitations of LCD backlighting currently make
>> LCDs greatly inferior to CRTs WRT to black levels & shadow detail. I
>> don't know of any LCD on the market that can match even a generic CRT in
>> that area.
>
>Unfortunately, no one seems to be able to describe precisely
>what these "limitations of LCD backlighting" ARE.

Well, that lack is easily remedied. ;) 
The limitation is due to the fact that LCD pixels work by phase-shifting
the light from the backlight through a colour filter & a sheet of
polarising film. Because the backlight must illuminate the entire screen
at the brightest possible luminance that may be required at any point on
the screen, & because it's not possible to make a pixel, (or the border
around it) 100% opaque, there will inevitably be some degree of light
leakage at any usable brightness setting.
(Note for non-experts: The brightness control on an LCD only sets the
brighness of the backlight - nothing else - so the brighter you set the
control, the more leakage you get.)
OTOH, CRTs illuminate each pixel by modulating an electron beam, & it's
trivial to drive the modulation to 0%. While it's true that you'll get a
certain amount of internal reflection in the faceplate of the CRT, it'll
be quite minimal on any correctly adjusted monitor, of even average
quality. The big weakness of CRTs is external reflection from that big
slab of glass. In a professional enviroment, you deal with that by
working under subdued, indirect lighting, & ideally have a light hood &
a CRT with a high quality anti-reflection coating.

> Nor do these
>factors ("black level" and "shadow detail") have anything to do
>with color gamut, which was the original point of disagreement.

I'm not arguing that particular point, as I don't think it's a question
that has an answer in the general case. Some CRTs will have a 'better'
gamut than some LCDs, & some LCDs will have a 'better' gamut than some
CRTs.

>However, since you've brought these items up, let's dispose of
>them as well.
>
>It is absolutely correct that the LCD panels as typically used in
>current monitor products provide a higher luminance at the
>"black" level than a properly-adjusted CRT. However, this
>is not necessarily indicative of an inherent inability of the LCD
>to match the CRT's performance in this area.

Well, yes & no. In engineering terms, it's inherently harder to design &
manufacture an LCD panel that is capable of similar black-levels to
those of a CRT, at similar brightness levels. That said, I agree that
it's not an insoluble problem *if* you throw enough effort & money at
the problem.

> As they have
>been driven by today's marketing expectations, LCD monitor
>panels also offer a very significantly higher white luminance
>(as much as 3-4X) over typical CRT monitor products.

Yes, but with the drawback that using your LCD at maximum brightness
dramatically brightens your blacks. Each LCD pixel only has a specific
contrast range, & its darkest value is not black. My experience has been
that the only way to get a usable (for photographic purposes) black is
to wind the brightness down to the minimum level that'll give me a
minimally-usable white level.

>Since the LCD does operate as a "light valve" - and it is
>impossible to completely block the light from the backlight
>- it is also correct to say that the LCD will, in practical terms,
>never provide an absolutely zero-luminance black. But then,
>neither does the CRT when properly adjusted. A CRT
>monitor's black level must be set very slightly above zero,
>or else the CRT cutoff point would have to be constantly
>adjusted (the black would tend to slip below blanking,
>making the lower end of the luminance range very non-linear).

Yes, all true. But that black level is still a hell of a lot lower than
anything I've seen on an LCD.

>Typical real-world values for the black-level luminance will
>be in the range of 0.05-0.5 cd/m^2 (most often toward the
>upper end of this range),

Yep. My CRT's currently reading a black level of 0.12 cd/m^2.

> vs. somewhere around 1 cd/m^2 or
>so for a typical monitor LCD.

Yes, that's the kind of number I've seen when calibrating my own LCD
monitors. (It's worth mentioning that in terms of human perception,
that's around a 9dB difference, or in photographic terms, 3 F-stops in
luminance. That's a *very* dramatic difference!)

> But since the LCD's white
>these days is up around 350-400 cd/m^2 (vs. something
>more like 100 for the CRT), simply cutting down the backlight
>output (or, in a more brute-force approach, filtering the LCD)
>would bring its black and white values down to something
>very comparable to the CRT.

Great minds think alike. ;)  That is exactly how I optimise the
black-levels on my LCDs. Unfortunately, I've found that they then fall
short on whites.

> That few products do this
>says much more about the demand in the market than it does
>anything at all about inherent differences in the technology.
>
>In terms of the "shadow detail" (i.e., the ability to
>discriminate "shades of gray" at the low end of the luminance
>range, we get back to differences in the response
>characteristics of the two technologies - which, if you'll
>look back over this thread, was my point in the first
>place.

Sure, I agree completely on that. (And we haven't even gotten to the
problem of poor monotonicity/tonal-resolution of LCD drive technology in
comparison to CRTs.) But unless I'm misunderstanding you, you're
agreeing that LCDs *are* weak on accuracy in shadow detail, & the fact
is that for my photographic work, tonal accuracy in the darker areas is
critically important. That's obviously not a major issue for probably
99% of the monitor market, but it is for many photographers.

To summarise my position:
(1) I'm not arguing gamut one way or the other, just contrast,
black-levels & tonal accuracy.
(2) In a typical environment, LCDs will usually give you a much better
contrast range, but in carefully controlled environment that's been
highly optimised for these purposes, a CRT is usually greatly superior
in those areas.

--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------
Anonymous
a b U Graphics card
October 1, 2004 7:35:12 PM

Archived from groups: rec.photo.digital,comp.sys.ibm.pc.hardware.video (More info?)

<usenet@imagenoir.com> wrote in message
news:48gpl09qearbl6l92bg4gvlgu0p8bkqp66@4ax.com...

> Well, that lack is easily remedied. ;) 
> The limitation is due to the fact that LCD pixels work by phase-shifting
> the light from the backlight through a colour filter & a sheet of
> polarising film. Because the backlight must illuminate the entire screen
> at the brightest possible luminance that may be required at any point on
> the screen, & because it's not possible to make a pixel, (or the border
> around it) 100% opaque, there will inevitably be some degree of light
> leakage at any usable brightness setting.

And guess what? You have a very similar problem
with a CRT. When properly set up (i.e., the "black
level" set to just ABOVE the cut-off point), the CRT
must emit some light as well. Lack of a true black in
CRTs has long been recognized as a problem with that
technology.


> OTOH, CRTs illuminate each pixel by modulating an electron beam, & it's
> trivial to drive the modulation to 0%.

Trivial, but an improper adjustment. If the "black"
is truly set at or below cutoff, you've entered a
very non-linear region of the CRT's operation.
Adjust it just barely above that, and it will very soon
drift back down below.


> Well, yes & no. In engineering terms, it's inherently harder to design &
> manufacture an LCD panel that is capable of similar black-levels to
> those of a CRT, at similar brightness levels. That said, I agree that
> it's not an insoluble problem *if* you throw enough effort & money at
> the problem.

Not at all. As has already been pointed out, the aim of
most current LCD designs has been high white luminance,
not low black. Adjusting the black level of the LCD to match
that of the CRT, AS LONG AS a comparable white
luminance is acceptable (i.e., around 100 cd/m^2 or so),
is actually pretty simple, since the LCD generally has more
than sufficient contrast.

> Yes, but with the drawback that using your LCD at maximum brightness
> dramatically brightens your blacks. Each LCD pixel only has a specific
> contrast range, & its darkest value is not black.

Exactly. But if set to comparable white luminances
(something that's rarely possible with the user brightness
control on an LCD), it's not very hard to get comparable
black.


> >Typical real-world values for the black-level luminance will
> >be in the range of 0.05-0.5 cd/m^2 (most often toward the
> >upper end of this range),
>
> Yep. My CRT's currently reading a black level of 0.12 cd/m^2.

Measured how? I don't necessarily doubt you,
but as has been pointed out it is very difficult to
get a decent black measurement.

Bob M.
October 5, 2004 4:26:11 PM

Archived from groups: rec.photo.digital,comp.sys.ibm.pc.hardware.video (More info?)

"Bob Myers" <nospamplease@address.invalid> wrote in message news:415dce76@usenet01.boi.hp.com...
>
> <usenet@imagenoir.com> wrote in message
> news:48gpl09qearbl6l92bg4gvlgu0p8bkqp66@4ax.com...
>
> > Well, that lack is easily remedied. ;) 
> > The limitation is due to the fact that LCD pixels work by phase-shifting
> > the light from the backlight through a colour filter & a sheet of
> > polarising film. Because the backlight must illuminate the entire screen
> > at the brightest possible luminance that may be required at any point on
> > the screen, & because it's not possible to make a pixel, (or the border
> > around it) 100% opaque, there will inevitably be some degree of light
> > leakage at any usable brightness setting.
>
> And guess what? You have a very similar problem
> with a CRT. When properly set up (i.e., the "black
> level" set to just ABOVE the cut-off point), the CRT
> must emit some light as well. Lack of a true black in
> CRTs has long been recognized as a problem with that
> technology.

It's a matter of degree. Yes it's an issue with CRT technology,
however it's a much bigger issue with LCD technology. That's
the point.

> > OTOH, CRTs illuminate each pixel by modulating an electron beam, & it's
> > trivial to drive the modulation to 0%.
>
> Trivial, but an improper adjustment. If the "black"
> is truly set at or below cutoff, you've entered a
> very non-linear region of the CRT's operation.
> Adjust it just barely above that, and it will very soon
> drift back down below.
>
>
> > Well, yes & no. In engineering terms, it's inherently harder to design &
> > manufacture an LCD panel that is capable of similar black-levels to
> > those of a CRT, at similar brightness levels. That said, I agree that
> > it's not an insoluble problem *if* you throw enough effort & money at
> > the problem.
>
> Not at all. As has already been pointed out, the aim of
> most current LCD designs has been high white luminance,
> not low black. Adjusting the black level of the LCD to match
> that of the CRT, AS LONG AS a comparable white
> luminance is acceptable (i.e., around 100 cd/m^2 or so),
> is actually pretty simple, since the LCD generally has more
> than sufficient contrast.
>
> > Yes, but with the drawback that using your LCD at maximum brightness
> > dramatically brightens your blacks. Each LCD pixel only has a specific
> > contrast range, & its darkest value is not black.
>
> Exactly. But if set to comparable white luminances
> (something that's rarely possible with the user brightness
> control on an LCD), it's not very hard to get comparable
> black.

Therefore, getting proper near blacks is rarely possible on an LCD.
Well said.

Rick
!