30-bit Color on 24-bit Hardware

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>.

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
48 answers Last reply
More about color hardware
  1. 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>.
    >
    > 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
  2. 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
  3. 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?
  4. 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.
  5. 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
  6. 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
  7. 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---
  8. 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.
  9. 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
  10. 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
  11. 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.
  12. 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"...
  13. 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.
  14. 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
  15. 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.
  16. 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:on4gl09e14bdf0be7a6r9jq6c3vur7733u@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.
  17. 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.
  18. 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.
  19. 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:DOh6d.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
  20. 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:DOh6d.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:DOh6d.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.
  21. 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.
  22. 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
  23. 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
    >
    >
  24. 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.
  25. 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
  26. 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
  27. 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
    ---^----^---------------------------------------------------------------
  28. 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.
  29. 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
    ---^----^---------------------------------------------------------------
  30. 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.
  31. 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/products/parhelia/256mb.cfm>

    --
    W
    . | ,. w , "Some people are alive only because
    \|/ \|/ it is illegal to kill them." Perna condita delenda est
    ---^----^---------------------------------------------------------------
  32. 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
  33. 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
  34. 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
    >
    >
  35. 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.
  36. 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.
  37. 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%20Screenshot%20(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%20Summary%20and%20Findings%20Report.pdf>

    Sorry it took me a while to get back to you,
    - Ron
  38. 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.
  39. 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
  40. 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.
  41. 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
  42. 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.
  43. 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.
  44. 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.
  45. 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.
  46. 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
    ---^----^---------------------------------------------------------------
  47. 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.
  48. 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
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