flat panel monitors

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

I've heard that flat panel monitors are easier on the eyes. Is this true?
If so, then what would be a good choice for a 17" for gaming?
116 answers Last reply
More about flat panel monitors
  1. Archived from groups: alt.comp.hardware,comp.sys.ibm.pc.hardware.video (More info?)

    On Thu, 9 Dec 2004 09:46:48 -0800, Adam Russell wrote:
    > I've heard that flat panel monitors are easier on the eyes. Is this true?
    > If so, then what would be a good choice for a 17" for gaming?

    Make sure you get a fast response time. There are monitors with 12ms
    now, like the Samsung 710T I think that's what I'm going to get... I
    just haven't decided yet if having a DVI interface is worth another $100

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

    Adam Russell writes:

    > I've heard that flat panel monitors are easier on the eyes.
    > Is this true?

    Any monitor with a clear, sharp, bright image and minimum flicker (which
    depends on your personal sensitivity to flicker) is easy on the eyes.
    It can be a CRT or a flat panel, as long as the image is of good
    quality.

    I try never to skimp on monitors. Eyes are worth taking care of.

    --
    Transpose hotmail and mxsmanic in my e-mail address to reach me directly.
  3. Archived from groups: comp.sys.ibm.pc.hardware.video (More info?)

    "John Oliver" <joliver@john-oliver.net> wrote in message
    news:slrncrhih9.nco.joliver@ns.sdsitehosting.net...
    > just haven't decided yet if having a DVI interface is worth another $100

    No question, I wouldn't buy one without it.

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

    Michael C writes:

    > No question, I wouldn't buy one without it.

    Is there really that much difference? I have only an analog input to
    mine, but even under a loupe the individual pixels are resolved as
    sharply as can be. How could a digital interface improve on that?

    --
    Transpose hotmail and mxsmanic in my e-mail address to reach me directly.
  5. Archived from groups: comp.sys.ibm.pc.hardware.video (More info?)

    > Mxsmanic <mxsmanic@hotmail.com> wrote:

    >> No question, I wouldn't buy one without it. [DVI-D]

    > Is there really that much difference?

    Yes. Several considerations:

    There is noise resulting from taking the original
    digital raster to analog and back to digital.
    This might display, for example as horizontal
    artifacts, unstable picture regions, etc.

    Square waves? No chance. Think of a pattern of
    alternating white/black 1-pix dots. In analog,
    these need to exhibit sharp transitions and flat
    tops to emulate what you get for free with DVI-D.
    Bandwidth limits in the analog channels are apt
    to smear this fine detail.

    Group delay with analog introduces some risk that
    the pixel data won't exactly precisely align with
    the LCD triads upon reconstruction. Suppose the
    analog signal has a little group delay (time shift)
    from the DAC, or in the cable, or in the ADC (or
    just one of the colors does). Our hypothetical white
    and black dots might become a gray moire morass.

    Even what black and white levels are, becomes
    uncertain with analog.

    I just compared the same screen in HD15 analog and
    DVI-D digital on my LCD, and the analog image has
    less "contrast", text characters are not as sharp,
    and due to the grayscale tracking limits of this
    monitor, black characters on white backgrounds have
    a tiny annoying pink fringe in analog.

    Go DVI-D. By the way, expect images and text to perhaps
    be startlingly sharper until you get used to it.
    The limitations of analog were providing some
    full-screen anti-aliasing at no extra charge.

    --
    Regards, Bob Niland mailto:name@ispname.tld
    http://www.access-one.com/rjn email4rjn AT yahoo DOT com
    NOT speaking for any employer, client or Internet Service Provider.
  6. Archived from groups: comp.sys.ibm.pc.hardware.video (More info?)

    Bob Niland writes:

    > There is noise resulting from taking the original
    > digital raster to analog and back to digital.
    > This might display, for example as horizontal
    > artifacts, unstable picture regions, etc.
    >
    > Square waves? No chance. Think of a pattern of
    > alternating white/black 1-pix dots. In analog,
    > these need to exhibit sharp transitions and flat
    > tops to emulate what you get for free with DVI-D.
    > Bandwidth limits in the analog channels are apt
    > to smear this fine detail.

    But the panel is just doing an analog to digital conversion, anyway, and
    the connection is analog even when it's DVI-D, so doesn't it all just
    wash?

    The image on mine is really sharp, it seems, and contrast is excellent.
    No artifacts even under a loupe. It makes me wonder how much better it
    could get.

    > Group delay with analog introduces some risk that
    > the pixel data won't exactly precisely align with
    > the LCD triads upon reconstruction.

    Doesn't the panel correct the time base for incoming analog signals or
    something, in order to avoid this? Like the TBC in some video
    equipment?

    > Suppose the
    > analog signal has a little group delay (time shift)
    > from the DAC, or in the cable, or in the ADC (or
    > just one of the colors does). Our hypothetical white
    > and black dots might become a gray moire morass.

    But the panel could delay everything and resync it to a new time base
    and eliminate any movement, like TBCs do for video.

    > I just compared the same screen in HD15 analog and
    > DVI-D digital on my LCD, and the analog image has
    > less "contrast", text characters are not as sharp,
    > and due to the grayscale tracking limits of this
    > monitor, black characters on white backgrounds have
    > a tiny annoying pink fringe in analog.
    >
    > Go DVI-D. By the way, expect images and text to perhaps
    > be startlingly sharper until you get used to it.
    > The limitations of analog were providing some
    > full-screen anti-aliasing at no extra charge.

    I don't know if my video card provides it. I have an NVidia GeForce2
    something-or-other, but I didn't notice a DVI-D plug on the card.
    There's one on the monitor, though.

    --
    Transpose hotmail and mxsmanic in my e-mail address to reach me directly.
  7. Archived from groups: comp.sys.ibm.pc.hardware.video (More info?)

    > Mxsmanic <mxsmanic@hotmail.com> wrote:

    > But the panel is just doing an analog to digital
    > conversion, anyway, ...

    No. With a DVI-D connection, the discrete pixel digital
    values are preserved from creation in the frame buffer
    by the graphics driver all the way out to the individual
    pixel drivers for the LCD triads.

    > ... and the connection is analog even when it's DVI-D,

    TMDS as I recall. Transition-Minimized Digital Signalling.
    Ones and zeros. Everything is either a 1, a 0, or ignored.

    >> ... group delay ...

    > Doesn't the panel correct the time base for incoming
    > analog signals or something, in order to avoid this?

    I'd like to think so, but I wouldn't assume it.
    Clearly, when we feed the monitor a non-native res,
    it cannot match pixels, because the rasters don't map.
    Interpolation time. It might still perform TBC to assure
    that active signal period start/end precisely align with
    the ADC's sampling aperture.

    >> Go DVI-D.

    > I don't know if my video card provides it.

    Most cards provide DVI-I ports, which have both one link
    of DVI-D digital and RGB analog (sometimes called DVI-A,
    plus a breakout-to-HD15 cable for analog use). By DVI-D,
    I mean use the card's DVI port, and a DVI cable, and
    assure yourself that if both signals are present, the
    monitor is using the digital, and not the analog.

    I'm using an aftermarket DVI-D cable which doesn't even
    have the RGB wires - turned out to not be necessary to
    be that drastic, but I didn't know that when I ordered
    the cable.

    --
    Regards, Bob Niland mailto:name@ispname.tld
    http://www.access-one.com/rjn email4rjn AT yahoo DOT com
    NOT speaking for any employer, client or Internet Service Provider.
  8. Archived from groups: comp.sys.ibm.pc.hardware.video (More info?)

    Bob Niland writes:

    > No. With a DVI-D connection, the discrete pixel digital
    > values are preserved from creation in the frame buffer
    > by the graphics driver all the way out to the individual
    > pixel drivers for the LCD triads.

    How many levels per pixel? An analog connection can have any number of
    levels, depending only on the quality of the connection and hardware.
    My card already generates 32-bit color, although my flat panel can't use
    all that resolution.

    > Most cards provide DVI-I ports, which have both one link
    > of DVI-D digital and RGB analog (sometimes called DVI-A,
    > plus a breakout-to-HD15 cable for analog use). By DVI-D,
    > I mean use the card's DVI port, and a DVI cable, and
    > assure yourself that if both signals are present, the
    > monitor is using the digital, and not the analog.

    I'll look again and see if there's a DVI-D plug, but I rather doubt it.

    --
    Transpose hotmail and mxsmanic in my e-mail address to reach me directly.
  9. Archived from groups: comp.sys.ibm.pc.hardware.video (More info?)

    > Mxsmanic <mxsmanic@hotmail.com> wrote:

    >> With a DVI-D connection, the discrete pixel digital
    >> values are preserved from creation in the frame buffer
    >> by the graphics driver all the way out to the individual
    >> pixel drivers for the LCD triads.

    > How many levels per pixel?

    I haven't looked at the DVI spec since 1.0, but at
    that time, single-link DVI was limited to 24 bpp,
    or 8-bits per R, G or B.

    > My card already generates 32-bit color, although my
    > flat panel can't use all that resolution.

    It's not clear to me that contemporary LCD panels can
    even deliver 24-bit color. They accept such signals,
    but what they paint on screen is another matter.

    > I'll look again and see if there's a DVI-D plug,
    > but I rather doubt it.

    The DVI(-I) connector is a D-sub, usually white body,
    with an 8x3 grid of pins, plus a 2x2 grid with
    cruciform ground planes for the RGB. If the
    connector is DVI-D (digital only), it omits the
    2x2 grid array and has only one of the ground blades.

    If your card only has 15-pin Dsub(s) (usually blue),
    then it only has analog video out. You cannot use a
    pure digital connection, athough you could invest in
    a monitor with DVI, and use it in analog mode until
    your next graphics card upgrade.

    --
    Regards, Bob Niland mailto:name@ispname.tld
    http://www.access-one.com/rjn email4rjn AT yahoo DOT com
    NOT speaking for any employer, client or Internet Service Provider.
  10. Archived from groups: comp.sys.ibm.pc.hardware.video (More info?)

    Bob Niland writes:

    > I haven't looked at the DVI spec since 1.0, but at
    > that time, single-link DVI was limited to 24 bpp,
    > or 8-bits per R, G or B.

    24-bit color isn't good enough for some applications. It doesn't
    provide enough levels in some parts of the gamut, such as blue (the eye
    is extremely sensitive to differences in intensity in the blue end of
    the spectrum, so any kind of posterization is very easy to spot).

    > It's not clear to me that contemporary LCD panels can
    > even deliver 24-bit color. They accept such signals,
    > but what they paint on screen is another matter.

    True for many cheaper CRTs, too. But it worries me that the standard
    apparently was designed in a way that permanently limits it to 24-bit
    color.

    > The DVI(-I) connector is a D-sub, usually white body,
    > with an 8x3 grid of pins, plus a 2x2 grid with
    > cruciform ground planes for the RGB. If the
    > connector is DVI-D (digital only), it omits the
    > 2x2 grid array and has only one of the ground blades.

    That doesn't sound familiar at all. The Web references I've found seem
    to claim that my card should have this, but I don't see it.

    > If your card only has 15-pin Dsub(s) (usually blue),
    > then it only has analog video out. You cannot use a
    > pure digital connection, athough you could invest in
    > a monitor with DVI, and use it in analog mode until
    > your next graphics card upgrade.

    This is what I've done. The performance even with analog input is very
    impressive, and ClearType works very well, also, even though it's
    supposedly designed for pure digital input.

    --
    Transpose hotmail and mxsmanic in my e-mail address to reach me directly.
  11. Archived from groups: comp.sys.ibm.pc.hardware.video (More info?)

    > Mxsmanic <mxsmanic@hotmail.com> wrote:

    > But it worries me that the [DVI] standard
    > apparently was designed in a way that
    > permanently limits it to 24-bit color.

    Not permanent - it just requires dual-link, and
    the pin assignments are already present in the
    existing connector.

    But yes, DVI was short-sighted. Another obvious
    limit was that a single link can only hit 1600x1200
    with normal blanking. Reduced timing (common) is
    hacked in to hit 1920x1200, but beyond that, dual-link
    is again required.

    >> The DVI(-I) connector is a D-sub, usually ...

    > That doesn't sound familiar at all.

    Here's a lousy photo of a bulkhead with both
    DVI and HD15:
    <http://www.hardocp.com/image.html?image=MTA4OTIzNDA3NzZ6ZkxtNW1xRXpfMV82X2wuanBn>

    --
    Regards, Bob Niland mailto:name@ispname.tld
    http://www.access-one.com/rjn email4rjn AT yahoo DOT com
    NOT speaking for any employer, client or Internet Service Provider.
  12. Archived from groups: comp.sys.ibm.pc.hardware.video (More info?)

    "Bob Niland" <email4rjn@yahoo.com> wrote in message
    news:opsiyzfkcvft8z8r@news.individual.net...
    > > Mxsmanic <mxsmanic@hotmail.com> wrote:
    >
    > >> No question, I wouldn't buy one without it. [DVI-D]
    >
    > > Is there really that much difference?
    >
    > Yes. Several considerations:

    Bob, as much as I hate to disagree with you, I'm afraid
    I'd have to vote "maybe" instead. For the most part, the
    differences between an analog and a digital interface for
    LCD monitors come down to questions of pixel timing,
    which really have nothing at all to do with whether the
    video information is in digital or analog form.

    The main factor in determining how good the displayed
    image is going to be with an analog interface is the generation
    of the proper clock with which to sample the analog video,
    which is a question of both getting the frequency right and
    making sure the clock is properly aligned with the incoming
    video such that the samples are taken where the "pixels" are
    supposed to be. (Being a continuous signal, of course, there
    is no information contained within the video itself which
    identifies the pixels.) Usually, the clock frequency is obtained
    by locking on to the horizontal sync pulese and multiplying THAT
    rate up to the assumed pixel rate; getting the alignment correct
    (the "phase" adjustment) is a matter of the interface circuitry
    making some educated guesses. But if the clock generation can
    be done properly, there is very little to be gained by simply having
    the pixel information in "digital" form. (And please consider how
    truly awful the digital interface would be if the pixel clock information
    were removed from it - it would be totally unusable. Hence my
    assertion that it is timing, not the encoding of the information, that
    is the key difference between these two types of interface.)

    >
    > There is noise resulting from taking the original
    > digital raster to analog and back to digital.
    > This might display, for example as horizontal
    > artifacts, unstable picture regions, etc.

    Nope; all of the above have to do with the timing of
    the pixel sampling process, not with noise in the video.
    (Oddly enough, the LCD is NOT inherently a "digital"
    device as is often assumed - fundamentally, the control
    of the pixel brightness in any LCD is an analog process.
    Simply having a discrete pixel array does not somehow
    make a display "digital," nor does it necessarily mean that
    a "digital" interface would have to be better.

    > Square waves? No chance. Think of a pattern of
    > alternating white/black 1-pix dots. In analog,
    > these need to exhibit sharp transitions and flat
    > tops to emulate what you get for free with DVI-D.
    > Bandwidth limits in the analog channels are apt
    > to smear this fine detail.

    If we were talking about a display that actually shows
    those edges, you'd have a point - but the LCD doesn't
    work that way. Remember, we are dealing with a
    SAMPLED analog video stream in this case; if the sample
    points happen at the right time (which again is a question
    of how well the pixel clock is generated), the pixel values
    are taken right "in the middle" of the pixel times - making
    the transitions completely irrelevant.

    Note that "digital" interfaces also have what is in effect a
    "bandwidth" limit (the peak pixel rate which can be supported),
    and it is in current interfaces often significantly less than what
    can be achieved with an "analog" connection. The single-link
    TMDS-based interfaces such as DVI (in its single channel
    form) and HDMI are both strictly limited to a pixel rate of
    165 MHz, while analog connections (even with the lowly
    VGA connector) routinely run with pixel rates in excess of
    200 MHz.

    > Group delay with analog introduces some risk that
    > the pixel data won't exactly precisely align with
    > the LCD triads upon reconstruction. Suppose the
    > analog signal has a little group delay (time shift)
    > from the DAC, or in the cable, or in the ADC (or
    > just one of the colors does). Our hypothetical white
    > and black dots might become a gray moire morass.

    Right - but again, a timing issue, which gets back to the
    question of the generation of the sampling clock, not the
    encoding of the data (which is really all that the terms "analog"
    and "digital" refer to). Again, take the clock away from
    a digital interface, and see what THAT gives you.

    So the logical question at this point is why no one has ever
    bothered to include better timing information on the analog
    interfaces. The answer now is: someone has. VESA released
    a new analog interface standard this past year which does just
    that - it includes a sampling clock reference, additional information
    which helps to properly locate the sampling clock with respect
    to the video stream, and even a system which makes the
    determination of the white and black levels much more accurate.
    This is called, oddly enough, the New Analog Video Interface
    standard, or simply NAVI. NAVI is supportable on a standard
    VGA connector, but the standard also includes the definition of a
    new, higher-performance analog connector (similar to the analog
    section of a DVI) for higher bandwidth and other features). It's
    not clear yet how well NAVI will be accepted in the industry, but
    it IS available if anyone chooses to use it.

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

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

    >>>> No question, I wouldn't buy one without it. [DVI-D]
    >>> Is there really that much difference?
    >> Yes. Several considerations:

    > Bob, as much as I hate to disagree with you, ...

    Sorry, but if I'm mistaken, netnews rules require you
    to disagree :-)

    > For the most part, the differences between an analog
    > and a digital interface for LCD monitors come down to
    > questions of pixel timing, which really have nothing
    > at all to do with whether the video information is in
    > digital or analog form.

    But there are opportunities for the signal to get
    visibly degraded if it goes to analog before it gets
    to the LCD panel lattice. In the entirely unscientific
    test I just ran, where I saw exactly what I expected to
    see, the analog happened to be running through two 2m
    lengths of HD15 cable and a KVM switch. The LCD image
    went from pixel-perfect to slightly fuzzy, and perhaps
    also reduced "contrast".

    > (And please consider how truly awful the digital
    > interface would be if the pixel clock information
    > were removed from it - it would be totally unusable.

    Well, that's the classic promise and peril of digital.
    It's either as perfect as it ever gets, or it's not
    there at all, whereas analog may never be perfect
    enough, and opportunities for degradation abound.

    >> There is noise resulting from taking the original
    >> digital raster to analog and back to digital.
    >> This might display, for example as horizontal
    >> artifacts, unstable picture regions, etc.
    >
    > Nope; all of the above have to do with the timing of
    > the pixel sampling process, not with noise in the video.

    Umm, if the bits in the frame buffer are going thru a
    DAC (which can introduce noise and distortion), then
    thru a cable (which <ditto>), even if the LCD is not using
    an ADC, and is using the analog signal directly, that
    extra noise and distortion may show up on screen.

    > (Oddly enough, the LCD is NOT inherently a "digital"
    > device as is often assumed - fundamentally, the control
    > of the pixel brightness in any LCD is an analog process.

    I sorta suspected that, but in the DVI-D model, the
    signal remains digital until it hits the rows & columns, no?

    Does the typical analog-only LCD have a DAC? Or does it
    just sample the analog signal and route values to drivers?
    My guess is that due to the interpolation required for
    handling arbitrary resolutions, there is a local frame
    buffer, and the analog video is [re]digitized before
    hitting the pel drivers.

    > If we were talking about a display that actually shows
    > those edges, you'd have a point - but the LCD doesn't
    > work that way. Remember, we are dealing with a
    > SAMPLED analog video stream in this case; if the sample
    > points happen at the right time (which again is a question
    > of how well the pixel clock is generated), the pixel values
    > are taken right "in the middle" of the pixel times - making
    > the transitions completely irrelevant.

    Even if the clocks align, there's also the matter of
    whether or not the analog signal has completely slewed
    to the value needed. If the DAC-cable-ADC path has
    bandwidth-limited (softened) the transitions, or
    introduced color-to-color skews, that will show up.
    I see it, or something like it, doing analog on my LCD.

    > ... the New Analog Video Interface standard, or simply
    > NAVI. ... It's not clear yet how well NAVI will be
    > accepted in the industry, but it IS available if
    > anyone chooses to use it.

    I suspect it's irrelevant at this point. Analog is
    the "economy" graphics connect now, and what we have
    is sufficient for the market.

    I think it more likely that the analog economy model
    will be replaced by a digital economy model, where PC
    main RAM is used for frame buffer, and the graphics
    "card" (if any) is just a TMDS driver chip with a
    DVI-D connector on the bulkhead, something like the
    "ADD2" cards I see at <www.molex.com>.

    --
    Regards, Bob Niland mailto:name@ispname.tld
    http://www.access-one.com/rjn email4rjn AT yahoo DOT com
    NOT speaking for any employer, client or Internet Service Provider.
  14. Archived from groups: comp.sys.ibm.pc.hardware.video (More info?)

    "Mxsmanic" <mxsmanic@hotmail.com> wrote in message
    news:ip9sr0pah4uh0eido84mnj4vov20tadouk@4ax.com...
    > But the panel is just doing an analog to digital conversion, anyway, and
    > the connection is analog even when it's DVI-D, so doesn't it all just
    > wash?

    And actually, the panel is THEN doing a digital to analog
    conversion; the LCD column drivers are basically just a series of
    D/A converters in parallel. The basic drive for an LCD is an
    analog voltage.

    > The image on mine is really sharp, it seems, and contrast is excellent.
    > No artifacts even under a loupe. It makes me wonder how much better it
    > could get.

    Clearly, in your case, not much at all. You have a monitor with
    a well-implemented analog front end.


    > Doesn't the panel correct the time base for incoming analog signals or
    > something, in order to avoid this? Like the TBC in some video
    > equipment?

    If the analog front end is doing its job properly, yes. This
    comes in the form of aligning the sampling clock with the
    incoming video stream.


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

    "Bob Niland" <email4rjn@yahoo.com> wrote in message
    news:opsiy0uld6ft8z8r@news.individual.net...

    > No. With a DVI-D connection, the discrete pixel digital
    > values are preserved from creation in the frame buffer
    > by the graphics driver all the way out to the individual
    > pixel drivers for the LCD triads.

    Well, they MIGHT be. In either an analog or digital
    interfaced LCD monitor, there is typically a look-up table
    in the monitor's front end which converts these values into
    somewhat different ones, in order to correct for the rather
    S-shaped (as opposed to a nice CRT-like "gamma" curve)
    response of the typical LC panel. In any event, though,
    whether or not having the information preserved in digital
    form is an advantage in terms of accuracy depends solely on
    whether or not the analog video signal is generated with, and
    can be read with, similar accuracy. 8 bits/color accuracy in
    an 0.7V analog signal says that the value of the LSB is about
    0.7/255 = 2.7 mV. At least with a VGA connection, it is
    difficult to get that level of accuracy on an instantaneous sample,
    but fortunately in a video situation what is actually perceived
    is the average of many samples, so this sort of visual
    performance is not out of the question. The best test, in
    either case, would be to take a look at a "gray scale" test
    pattern with the appropriate number of values, and see if you're
    satisfied with the result.


    > TMDS as I recall. Transition-Minimized Digital Signalling.
    > Ones and zeros. Everything is either a 1, a 0, or ignored.

    Close - Transition Minimized Differential Signalling, referring
    to both the encoding method used and the fact that the individual
    data connections are current-differential pairs (sort of). But
    the notion that everything in a "digital" connection is either a
    1 or a 0 or ignored is somewhat misleading; nothing is ignored,
    and it's a question of both the original transmitted data AND
    noise on the line as to whether the received information will be
    interpreted as a 1 or a 0 ("ignored" to the receiver is not possible;
    it HAS to be interpreted as a 1 or a 0, as those are the only
    possible outputs.) Digital connections are certainly not immune
    to noise - they simply respond to it in a different manner. (Analog
    degrades more gracefully in the presence of noise, as the LSBs
    are effectively lost first; in "digital," everything stays great right
    up to the point where the noise margin is exceeded, and then
    everything is lost completely.)

    >
    > >> ... group delay ...
    >

    > I'd like to think so, but I wouldn't assume it.
    > Clearly, when we feed the monitor a non-native res,
    > it cannot match pixels, because the rasters don't map.

    Again, this is not a distinction between analog and digital
    interfaces. In both cases, the incoming video information
    is sampled at its "native" mode (i.e., if you have an analog
    interface carrying, say, a 1280 x 1024 image, then there will
    be 1280 samples taken per active line, no matter what the
    panel format is). Image scaling is done later in the pipe, in
    both analog- and digital-input cases. (It would be far worse
    in the digital case if this were not true.)


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

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

    > In either an analog or digital interfaced LCD monitor,
    > there is typically a look-up table in the monitor's
    > front end which converts these values into somewhat
    > different ones, in order to correct for the rather
    > S-shaped (as opposed to a nice CRT-like "gamma" curve)

    The monitor knows that the incoming data will be
    pre-compensated to a gamma (log curve) in the 1.8 ... 2.6
    range, or maybe be linear (no re-comp).

    Why doesn't the look-up more fully adjust-out the
    S-curve, so that color errors that can be corrected
    with the simple exponent adjustment of typical graphics
    card gamma control menus?

    My guess is that because LCD subpixels are just barely
    8-bit, a full correction might minimize color errors at
    the expense of introducing visible terracing in gradients.

    And the solution relies on future 10-bit panels.

    --
    Regards, Bob Niland mailto:name@ispname.tld
    http://www.access-one.com/rjn email4rjn AT yahoo DOT com
    NOT speaking for any employer, client or Internet Service Provider.
  17. Archived from groups: comp.sys.ibm.pc.hardware.video (More info?)

    "Mxsmanic" <mxsmanic@hotmail.com> wrote in message
    news:p1csr01gsvonbu3om7cb7i9gdd64v9t1fq@4ax.com...
    > How many levels per pixel? An analog connection can have any number of
    > levels, depending only on the quality of the connection and hardware.
    > My card already generates 32-bit color, although my flat panel can't use
    > all that resolution.

    Slight correction time here - "32-bit color" generally does NOT
    imply more than 8 bits per primary. What is called "32 bit color"
    in the PC world is really just a way to align 24 bits of information
    (8 each of RGB) within a four-byte space, for ease of handling the
    data (as opposed to having the video information coming in three-byte
    packets).


    > > Most cards provide DVI-I ports, which have both one link
    > > of DVI-D digital and RGB analog (sometimes called DVI-A,
    > > plus a breakout-to-HD15 cable for analog use). By DVI-D,
    > > I mean use the card's DVI port, and a DVI cable, and
    > > assure yourself that if both signals are present, the
    > > monitor is using the digital, and not the analog.
    >
    > I'll look again and see if there's a DVI-D plug, but I rather doubt it.

    To clarify the DVI terminology here:

    DVI-I is a DVI implementation in which RGB analog signals
    are provided along with one OR two TMDS links; either interface
    may be used, although they might not have identical capabilities.
    (Often, two different EDID files will be provided in the monitor,
    each of which describes the monitor's capabilities on one of the
    two interfaces.)

    DVI-D is a variant of DVI which does not carry analog video,
    and so does not provide pins in that part of the connector. It
    too may provide either one or two TMDS links, AKA "channels."
    Each channel carries three data pairs, and has a capacity of
    up to 165 Mpixels/second, 24 bits/pixel.


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

    "Mxsmanic" <mxsmanic@hotmail.com> wrote in message
    news:i6usr0td89lmed0d0svan3jtmrj4d83kva@4ax.com...

    > 24-bit color isn't good enough for some applications. It doesn't
    > provide enough levels in some parts of the gamut, such as blue (the eye
    > is extremely sensitive to differences in intensity in the blue end of
    > the spectrum, so any kind of posterization is very easy to spot).

    Well, actually, it's the green region of the spectrum
    where the eye has its best discrimination ability, but that's
    beside the point. You're right in noting that 8 bits/color is
    not sufficient for many demanding applications, especially if
    a linear encoding is assumed. Somewhere in the 10-12 bit
    region is generally considered adequate for just about anything,
    though.

    >
    > > It's not clear to me that contemporary LCD panels can
    > > even deliver 24-bit color. They accept such signals,
    > > but what they paint on screen is another matter.
    >
    > True for many cheaper CRTs, too. But it worries me that the standard
    > apparently was designed in a way that permanently limits it to 24-bit
    > color.

    Yes and no. DVI DOES provide the option of a second
    link, which could be used for either greater "color depth"
    or support for higher "resolutions" (in the pixel format
    sense of the word). It's just rarely used in this manner, in
    part due to the lack of panels which support more than 8 bits
    per primary at present.


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

    Bob Niland writes:

    > Here's a lousy photo of a bulkhead with both
    > DVI and HD15:

    Nope, I don't have that.

    By the way, does anyone build video cards optimized for 2D, photographic
    and prepress use, instead of always emphasizing animation and 3D
    performance?

    --
    Transpose hotmail and mxsmanic in my e-mail address to reach me directly.
  20. Archived from groups: comp.sys.ibm.pc.hardware.video (More info?)

    > Mxsmanic <mxsmanic@hotmail.com> wrote:

    > By the way, does anyone build video cards optimized
    > for 2D, photographic and prepress use, instead of
    > always emphasizing animation and 3D performance?

    Yes. Matrox (which is what I use):
    <http://www.matrox.com/mga/home.htm>

    They are way behind in 3D perf, and only just
    announced their first PCI-Express card.

    --
    Regards, Bob Niland mailto:name@ispname.tld
    http://www.access-one.com/rjn email4rjn AT yahoo DOT com
    NOT speaking for any employer, client or Internet Service Provider.
  21. Archived from groups: comp.sys.ibm.pc.hardware.video (More info?)

    Bob Myers writes:

    > Bob, as much as I hate to disagree with you, I'm afraid
    > I'd have to vote "maybe" instead. For the most part, the
    > differences between an analog and a digital interface for
    > LCD monitors come down to questions of pixel timing,
    > which really have nothing at all to do with whether the
    > video information is in digital or analog form.

    The best analog system will always beat the performance of the best
    digital system. There's nothing about analog technology that makes it
    intrinsically inferior to digital, so a good video card and a good
    monitor should meet or beat any digital interface, I should think.

    This is why the _best_ analog audio systems can consistently beat the
    best digital systems. However, the superior performance comes at a
    price that is usually all out of proportion with the increment of gain
    over digital.

    > Oddly enough, the LCD is NOT inherently a "digital"
    > device as is often assumed - fundamentally, the control
    > of the pixel brightness in any LCD is an analog process.

    Every interface between the digital world and the physical world is
    analog, so all input and output devices are ultimately analog devices.
    "Digital" only means something in the conceptual world of information
    representation.

    --
    Transpose hotmail and mxsmanic in my e-mail address to reach me directly.
  22. Archived from groups: comp.sys.ibm.pc.hardware.video (More info?)

    > Mxsmanic <mxsmanic@hotmail.com> wrote:

    > The best analog system will always beat the
    > performance of the best digital system.

    Depending on how you define "best", as we saw with the
    early debates about CD audio. Now that purists can get
    48-bit 96 KHz digital audio, I don't see that debate
    anymore.

    > Every interface between the digital world and the
    > physical world is analog, ...

    Not at the quantum level.
    Expect the physicists to sail in here and dispute that :-)

    Is anyone prepared to argue that using an HD15 analog
    connection to an LCD monitor provides a "better" presentation?

    It's conceivable, due to the anti-aliasing provided by the
    analog blur. I was actually a bit startled by how crisp
    the screen was using the DVI-D connection. In my CAD work,
    I now always see stair-casing of angled and curved lines,
    whereas on the CRT monitor (same res), they were smooth.

    --
    Regards, Bob Niland mailto:name@ispname.tld
    http://www.access-one.com/rjn email4rjn AT yahoo DOT com
    NOT speaking for any employer, client or Internet Service Provider.
  23. Archived from groups: comp.sys.ibm.pc.hardware.video (More info?)

    Bob Niland writes:

    > Well, that's the classic promise and peril of digital.
    > It's either as perfect as it ever gets, or it's not
    > there at all, whereas analog may never be perfect
    > enough, and opportunities for degradation abound.

    Analog can also be more perfect than digital. In fact, it is always
    possible to build an analog system that is superior to any given digital
    system--if money is no object.

    > Umm, if the bits in the frame buffer are going thru a
    > DAC (which can introduce noise and distortion), then
    > thru a cable (which <ditto>), even if the LCD is not using
    > an ADC, and is using the analog signal directly, that
    > extra noise and distortion may show up on screen.

    Sure, but the question is whether or not it actually does to any visible
    extent in the real world.

    I've found that, in many respects, PC video systems perform better than
    they are supposed to. For all the noise one hears about the horrors of
    analog systems, in real life they perform amazingly well. Look no
    further than the continuing superiority of CRTs for most aspects of
    image quality for proof.

    > I suspect it's irrelevant at this point. Analog is
    > the "economy" graphics connect now, and what we have
    > is sufficient for the market.

    Economy perhaps, but that isn't always correlated with quality.

    > I think it more likely that the analog economy model
    > will be replaced by a digital economy model, where PC
    > main RAM is used for frame buffer, and the graphics
    > "card" (if any) is just a TMDS driver chip with a
    > DVI-D connector on the bulkhead, something like the
    > "ADD2" cards I see at <www.molex.com>.

    I suspect the current "high-performance" digital models will become the
    "digital economy" models, in time.

    --
    Transpose hotmail and mxsmanic in my e-mail address to reach me directly.
  24. Archived from groups: comp.sys.ibm.pc.hardware.video (More info?)

    Bob Niland writes:

    > My guess is that because LCD subpixels are just barely
    > 8-bit, a full correction might minimize color errors at
    > the expense of introducing visible terracing in gradients.

    The incoming data might be 8-bit, but there's no reason why the internal
    correction of the monitor can't be carried out with much higher
    granularity.

    --
    Transpose hotmail and mxsmanic in my e-mail address to reach me directly.
  25. Archived from groups: comp.sys.ibm.pc.hardware.video (More info?)

    Bob Niland writes:

    > They are way behind in 3D perf, and only just
    > announced their first PCI-Express card.

    But are they ahead in 2D performance and image quality? I have a
    Millennium II card in my oldest PC, which as always served very well.

    --
    Transpose hotmail and mxsmanic in my e-mail address to reach me directly.
  26. Archived from groups: comp.sys.ibm.pc.hardware.video (More info?)

    > Mxsmanic <mxsmanic@hotmail.com> wrote:

    >> They are way behind in 3D perf, and only just
    >> announced their first PCI-Express card.

    > But are they ahead in 2D performance and image quality? I have a
    > Millennium II card in my oldest PC, which as always served very well.

    It depends on your applications, operating system,
    PC, and graphics slot (AGP, PCI, PCI-X or PCIe).
    You need to hit some forums devoted to your key
    apps and get advice.

    The two most graphics-intensive things I do, Photoshop
    and IMSI TurboCAD, seem to get no particular benefit
    from the accelerations available on ATI and Nvidia cards,
    and perform quite adequately on a Matrox Parhelia.

    Photoshop is compute and bus-bound.

    TC uses OGL, but only for modes where performance isn't
    an issue anyway. In fully-rendered mode, it's doing that
    entirely in host software, and is purely compute-bound.

    If I ran games, the config might have been different.

    --
    Regards, Bob Niland mailto:name@ispname.tld
    http://www.access-one.com/rjn email4rjn AT yahoo DOT com
    NOT speaking for any employer, client or Internet Service Provider.
  27. Archived from groups: comp.sys.ibm.pc.hardware.video (More info?)

    Bob Niland writes:

    > I was actually a bit startled by how crisp
    > the screen was using the DVI-D connection. In my CAD work,
    > I now always see stair-casing of angled and curved lines,
    > whereas on the CRT monitor (same res), they were smooth.

    I doubt that this is a result of switching to a digital connection.

    Note also that aliasing is usually a sign of lower resolution, not
    higher resolution.

    --
    Transpose hotmail and mxsmanic in my e-mail address to reach me directly.
  28. Archived from groups: comp.sys.ibm.pc.hardware.video (More info?)

    > Mxsmanic <mxsmanic@hotmail.com> wrote:

    >> I was actually a bit startled by how crisp
    >> the screen was using the DVI-D connection. In my CAD work,
    >> I now always see stair-casing of angled and curved lines,
    >> whereas on the CRT monitor (same res), they were smooth.

    > I doubt that this is a result of switching to a digital connection.

    Re-running the comparison, I see that it was partly due
    to going digital, but mostly due to switching to LCD.
    The former CRT (same res) was providing some additional
    de-crisping :-)

    > Note also that aliasing is usually a sign of lower
    > resolution, not higher resolution.

    In this case, I'm making no changes to the video setup
    when I switch between CRT and LCD, or analog and digital
    on the LCD.

    Just playing around in analog mode on the LCD, I see
    not only the pink halo on black-on-white objects, but
    also some ghosting (or ringing). Likely a result of the
    KVM switch and extra cable in that path.

    And painting a test pattern with alternating single-pixel
    white-black, the white is not pure (but, impressively,
    the alignment of the data and display rasters is perfect);
    no gray moire.

    --
    Regards, Bob Niland mailto:name@ispname.tld
    http://www.access-one.com/rjn email4rjn AT yahoo DOT com
    NOT speaking for any employer, client or Internet Service Provider.
  29. Archived from groups: comp.sys.ibm.pc.hardware.video (More info?)

    "Bob Niland" <email4rjn@yahoo.com> wrote in message
    news:opsi0je4o1ft8z8r@news.individual.net...

    > The monitor knows that the incoming data will be
    > pre-compensated to a gamma (log curve) in the 1.8 ... 2.6
    > range, or maybe be linear (no re-comp).

    No, the monitor knows nothing about how the incoming
    video data is biased; the video source (the host PC) MAY
    apply a pre-compensation based on what it knows of the
    monitor's response curve (based on the gamma value given
    in EDID). But the "correction" the host applies to the
    video data is not the issue here. (Whether or not any
    correction SHOULD be applied is another matter, and one
    that probably deserves some attention later on.) But all
    the monitor really knows is that it's getting such-and-such
    an input level.

    The problem is that while the CRT provides, just by its
    nature, a nice "gamma" curve (it's nice for a number of
    reasons, not the least of which is that it's a very good match
    to the inverse of the human eye's own response curve -
    the bottom line result being that linear increases in the input
    video level LOOK linear to the eye, even though the actual
    output of light from the tube is varying in an objectively
    non-linear fashion), the LCD does not do this. The LCD's
    natural response curve, from a perceptual standpoint, is
    ugly - a S-shaped curve which is sort of linear in the
    middle and flattens out at both the black and white ends.


    > Why doesn't the look-up more fully adjust-out the
    > S-curve, so that color errors that can be corrected
    > with the simple exponent adjustment of typical graphics
    > card gamma control menus?
    >
    > My guess is that because LCD subpixels are just barely
    > 8-bit, a full correction might minimize color errors at
    > the expense of introducing visible terracing in gradients.

    Even if they're fully eight bits, that's not enough IF you
    are also advertising to the outside world (i.e., to those
    devices ahead of the LUT) that you're providing a true
    eight-bit accuracy. You've already mapped some of those
    values off what they're expected to be, which in effect
    will compress the curve in some areas and cause, for
    instance, two successive input values to result in the same
    ONE output value. You need finer control of the pixel
    gray level, relative to the specified accuracy of the input
    data, to be able to both compensate the response curve
    AND provide that specified accuracy at all levels.

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

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

    >> The monitor knows that the incoming data will be
    >> pre-compensated to a gamma (log curve) in the 1.8 ... 2.6
    >> range, or maybe be linear (no re-comp).

    > No, the monitor knows nothing about how the incoming
    > video data is biased; the video source (the host PC) MAY
    > apply a pre-compensation based on what it knows of the
    > monitor's response curve (based on the gamma value given
    > in EDID).

    I was using "know" in the metaphorical sense. The
    monitor maker knows that the signal is apt to be
    either linear, or pre-comped in the 1.8 - 2.6 gamma
    range ...

    .... and that if the user has any tool for dealing with
    a mismatch of expectations, it's apt to be just a simple
    exponent control, and maybe ganged (can't separately
    adjust R, G and B).

    > (Whether or not any correction SHOULD be applied is
    > another matter, and one that probably deserves some
    > attention later on.)

    Is a gamma standard a topic of any of the follow-on
    standards to DVI? Packet? Send-changed-data-only?

    > Even if they're fully eight bits, that's not enough IF you
    > are also advertising to the outside world (i.e., to those
    > devices ahead of the LUT) that you're providing a true
    > eight-bit accuracy. You've already mapped some of those
    > values off what they're expected to be, which in effect
    > will compress the curve in some areas and cause, for
    > instance, two successive input values to result in the same
    > ONE output value. You need finer control of the pixel
    > gray level, relative to the specified accuracy of the input
    > data, to be able to both compensate the response curve
    > AND provide that specified accuracy at all levels.

    No problem, just do error-diffused dithering in the
    monitor's full-frame buffer :-)

    Now this could be done in the host, but then we'd need
    some new VESA standard for reading back the tables of
    stuck values.

    --
    Regards, Bob Niland mailto:name@ispname.tld
    http://www.access-one.com/rjn email4rjn AT yahoo DOT com
    NOT speaking for any employer, client or Internet Service Provider.
  31. Archived from groups: comp.sys.ibm.pc.hardware.video (More info?)

    "Mxsmanic" <mxsmanic@hotmail.com> wrote in message
    news:acjur0la3u84nchrn17juprb3d0iuadssb@4ax.com...
    > The incoming data might be 8-bit, but there's no reason why the internal
    > correction of the monitor can't be carried out with much higher
    > granularity.

    The "granularity" of the look-up table data is not the
    limiting factor; it's the number of bits you have at the
    input to the panel, vs. the numer of bits you claim to
    have at the input to the overall system. If I map 8-bit
    input data to, say, 10-bit outputs from the look up
    table, I don't get as good a result as I want if the panel
    itself has only 8 bits of accuracy. I need to at the very
    least call in some additional tricks (which ARE available
    - some frame-to-frame dithering can help, for example)
    to be able to take advantage of the greater accuracy in
    in the middle of the chain.

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

    "Bob Niland" <email4rjn@yahoo.com> wrote in message
    news:opsi0bkbqcft8z8r@news.individual.net...

    > But there are opportunities for the signal to get
    > visibly degraded if it goes to analog before it gets
    > to the LCD panel lattice. In the entirely unscientific
    > test I just ran, where I saw exactly what I expected to
    > see, the analog happened to be running through two 2m
    > lengths of HD15 cable and a KVM switch. The LCD image
    > went from pixel-perfect to slightly fuzzy, and perhaps
    > also reduced "contrast".

    Oh, sure - but then, that's a bad thing to do to any connection.
    Have you tried the corresponding experiment with a
    digital interface running at its max. pixel rate? (Nope -
    because passive switchboxes and the like simply don't
    work with digital interfaces.) In an apples-to-apples
    comparison, say a VGA vs. a DVI over the standard
    2-3 meters of good quality cable in each case, the
    differences you will see are due to sampling errors in the
    analog case. Or in other words, the advantage of the digital
    interface is that it brings its "sampling clock" along with
    the data.


    > Umm, if the bits in the frame buffer are going thru a
    > DAC (which can introduce noise and distortion), then
    > thru a cable (which <ditto>), even if the LCD is not using
    > an ADC, and is using the analog signal directly, that
    > extra noise and distortion may show up on screen.

    Sure; the question is always going to be whether or not
    that "noise and distortion" is below the level we care
    about. Digital interfaces are not error-free, either; that
    they are acceptable, when they are, is the result of the bit
    rate being below perceivable levels. Similarly, if the analog
    interface delivers a stable image with the video data to
    the desired level of amplitude accuracy (in most cases here,
    to an 8 bit/sample level, or an accuracy of about +/- 1,5 mV
    in "analog" terms), the difference between the two interfaces
    will not be distinguishable. It is ALWAYS a matter of how
    good is good enough, and neither type of connection is
    ever truly "perfect."


    > I sorta suspected that, but in the DVI-D model, the
    > signal remains digital until it hits the rows & columns, no?

    Well, until it hits the column drivers, yes. On the other hand,
    there HAVE been LCD panels made, notably by NEC,
    which preserved the analog video signal in analog form clear
    through to the pixel level.


    > Does the typical analog-only LCD have a DAC? Or does it
    > just sample the analog signal and route values to drivers?

    It has an ADC right up front - it generally has to, especially
    if it supports any sort of image scaling, which is definitely
    something best done in the digital domain. Scaling does
    not necessarily imply a full frame buffer; modern scalers
    make do with a few lines' worth of buffering, unless
    frame rate conversion is also required - in which case at
    least a good deal of a frame's worth of data must be stored,
    and in the best versions a full frame buffer or two of memory
    is used.


    > Even if the clocks align, there's also the matter of
    > whether or not the analog signal has completely slewed
    > to the value needed. If the DAC-cable-ADC path has
    > bandwidth-limited (softened) the transitions, or
    > introduced color-to-color skews, that will show up.
    > I see it, or something like it, doing analog on my LCD.

    Sure - but you can't really lay the blame for having a BAD
    analog interface on analog connections in general. The
    point is that a very good interface is still most definitely possible
    in the analog domain, and is in fact achieved quite often. There
    are also analog systems which take advantage of the rather
    forgiving nature of analog to enable truly cheap and nasty
    cables, connectors, etc., at the expense of performance.
    Digital, as noted, either works or it doesn't - which is a big
    part of the reason that digital interfaces are not as inexpensive
    as the cheapest (and lowest quality!) of the analog types.
    You simply HAVE to meet a certain minimum level of
    performance with digital, or you don't get to play AT ALL.

    > > ... the New Analog Video Interface standard, or simply
    > > NAVI. ... It's not clear yet how well NAVI will be
    > > accepted in the industry, but it IS available if
    > > anyone chooses to use it.
    >
    > I suspect it's irrelevant at this point. Analog is
    > the "economy" graphics connect now, and what we have
    > is sufficient for the market.

    Possibly; we'll see how it plays out. While digital
    interfaces are becoming a lot more popular, analog
    connections still account for well over 80% of the
    video actually being used in the desktop monitor
    market, even though LCDs took over from CRTs
    as the unit volume leader this past year. As you know,
    a gargantuan installed base has certain advantages
    (or problems, which is often a different word for the
    same thing! :-)).

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

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

    >> > ... the New Analog Video Interface standard, or simply
    >> > NAVI. ... It's not clear yet how well NAVI will be
    >> > accepted in the industry, but it IS available if
    >> > anyone chooses to use it.

    >> I suspect it's irrelevant at this point. Analog is
    >> the "economy" graphics connect now, and what we have
    >> is sufficient for the market.

    > Possibly; we'll see how it plays out. While digital
    > interfaces are becoming a lot more popular, analog
    > connections still account for well over 80% of the
    > video actually being used in the desktop monitor
    > market, even though LCDs took over from CRTs
    > as the unit volume leader this past year. As you know,
    > a gargantuan installed base has certain advantages
    > (or problems, which is often a different word for the
    > same thing! :-)).

    Does NAVI bring any benefits to the installed base of
    CRTs? Does it matter if it does?

    If it does bring benefits to LCD via analog connect,
    does that matter? I suspect the users who care about
    whatever NAVI promises, will tend to go digital.

    And I have a suspicion that the temptation on entry-
    level PCs in the near future will be an analog-free
    connection. A dumb UMA frame buffer, exposed thru a
    TMDS chip thru a DVI-D (only) port on the back panel,
    thru a DVI-D (only) cable, to a DVI-D (only) monitor.
    Omits a couple of buffers, a DAC, an ADC (maybe) and
    some copper. Maybe only runs at native res. Does DVI
    allow captive cable at display?

    The entire concept of "high end CRT" is already dead,
    and increasingly what remains of new CRTs in the market
    will tend toward junk (or be seen as so). The momentum
    to flat panel (LCD or not) may cause the entire analog
    graphics connection to go the way of the impact printer
    before NAVI can get a foothold.

    --
    Regards, Bob Niland mailto:name@ispname.tld
    http://www.access-one.com/rjn email4rjn AT yahoo DOT com
    NOT speaking for any employer, client or Internet Service Provider.
  34. Archived from groups: comp.sys.ibm.pc.hardware.video (More info?)

    "Mxsmanic" <mxsmanic@hotmail.com> wrote in message
    news:voiur0ltbpk88i1aehf4g17qsotq7cumb5@4ax.com...
    > Analog can also be more perfect than digital. In fact, it is always
    > possible to build an analog system that is superior to any given digital
    > system--if money is no object.

    Exactly. Both are simply means of encoding information
    for transmission; when comparing "analog" to "digital," the
    best that you can ever do is to compare one given
    implementation of "analog" vs.a given implementation of
    "digital." Neither "analog" nor "digital" is inherently
    superior to the other, per se. Each has its own advantages
    and disadvantages, and there is a lot of misunderstanding
    as to just what those are in each of these.

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

    "Mxsmanic" <mxsmanic@hotmail.com> wrote in message
    news:fdiur09qghsmlp0pa3bscnpk7ts7iidocb@4ax.com...
    > The best analog system will always beat the performance of the best
    > digital system.

    Unfortunately, I'm going to have to disagree with that, as
    well; as I noted in another response here, neither type of
    interface, per se, is inherently superior to the other.
    Both are ultimately limited by the Gospel According to
    St. Shannon, which puts strict limits on how much data
    you can get through a given channel REGARDLESS of
    how that data is encoded. Now, a particular sort of
    a digital interface may or may not be superior to a
    particular sort of analog; it depends on the specific
    characteristics of the interfaces in question, and just what
    is important, in a given application, in determining
    "superior."


    > This is why the _best_ analog audio systems can consistently beat the
    > best digital systems.

    That's not the only reason for this; high-end audio also
    incorporates huge dollops of what can only be seen as
    "religious" beliefs, with no basis in reasoning or evidence,
    re a given individuals' views on what is "superior." (I
    mean no disrespect to religion in saying this; I am simply
    noting that there is a difference in kind between a belief
    held solely on faith, and one arrived at through a careful
    and objective consideration of evidence.) In the case of
    audio, an awful lot of what has been claimed for the various
    "digital" and "analog" systems is quite simply wrong.
    (This isn't the place for that discussion - I'm sure it
    continues, unfortunately quite healthy after all these years,
    over in rec.audio.high-end, a group I left a long time ago
    for just this reason. There's just no sense in discussing
    something when very few are interested in anything
    other than argument by vigorous assertion.)


    >
    > > Oddly enough, the LCD is NOT inherently a "digital"
    > > device as is often assumed - fundamentally, the control
    > > of the pixel brightness in any LCD is an analog process.
    >
    > Every interface between the digital world and the physical world is
    > analog, so all input and output devices are ultimately analog devices.

    No. This is a common misconception regarding what is
    meant by the term "analog." It does NOT necessarily mean
    a system which is "continuous," "linear," etc., even though
    in the most common forms of analog systems these are
    often also true. "Analog" simply refers to a means of encoding
    information in which one parameter is varied in a manner
    ANALOGOUS TO (and hence the name) another - for
    example, voltage varying in a manner analogous to the original
    variations in brightness or sound level. The real world is
    not "analog" - it is simply the real world. "Analog" points
    to one means of describing real-world events, as does
    "digital."

    > "Digital" only means something in the conceptual world of information
    > representation.

    "Digital" is simply another means of representing information;
    one in which the information is described as a series of
    "digits" (numbers), and again, this is reflected in the name.
    It is neither inherently less accurate or more accurate than
    "analog" per se - that comparison always depends on the
    specifics of the two implementations in question.

    If you want a truly painful and detailed treatment of this
    question (well, it HAS been one of my hot butons), I
    spent a whole chapter on the subject in my book
    "Display Interfaces: Fundamentals & Standards."


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

    "Bob Niland" <email4rjn@yahoo.com> wrote in message
    news:opsi0l3q0rft8z8r@news.individual.net...
    > Is anyone prepared to argue that using an HD15 analog
    > connection to an LCD monitor provides a "better" presentation?

    Sure - but first, you have to define "better." :-)

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

    Bob Niland writes:

    > Re-running the comparison, I see that it was partly due
    > to going digital, but mostly due to switching to LCD.
    > The former CRT (same res) was providing some additional
    > de-crisping :-)

    Remember that, in theory, there's no fixed upper limit to horizontal
    resolution on a CRT, although the mask or grille spacing imposes some
    practical restrictions. So you could be seeing additional detail on the
    CRT that the LCD cannot display, in some cases.

    > Just playing around in analog mode on the LCD, I see
    > not only the pink halo on black-on-white objects, but
    > also some ghosting (or ringing). Likely a result of the
    > KVM switch and extra cable in that path.

    It has to be distortion of the signal. The panel is just going to
    sample the signal, so if there's a pink halo on the screen, there's one
    in the signal.

    I'm happy to say that I see no such artifacts on my screen. I just have
    a simple 2-metre cable betwixt PC and panel (the cable supplied with the
    panel).

    > And painting a test pattern with alternating single-pixel
    > white-black, the white is not pure (but, impressively,
    > the alignment of the data and display rasters is perfect);
    > no gray moire.

    Maybe you just need to remove the switch and cable.

    --
    Transpose hotmail and mxsmanic in my e-mail address to reach me directly.
  38. Archived from groups: comp.sys.ibm.pc.hardware.video (More info?)

    > Mxsmanic <mxsmanic@hotmail.com> wrote:

    >> Re-running the comparison, I see that it was partly due
    >> to going digital, but mostly due to switching to LCD.
    >> The former CRT (same res) was providing some additional
    >> de-crisping :-)

    > Remember that, in theory, there's no fixed upper limit to
    > horizontal resolution on a CRT, although the mask or grille
    > spacing imposes some practical restrictions.

    Not to mention circuit bandwidth, beam spot size,
    beam focus and grill diffraction.

    > So you could be seeing additional detail on the
    > CRT that the LCD cannot display, in some cases.

    My impression is less detail on the CRT. Each LCD triad
    definitely represents one graphics card frame buffer pixel.
    On the CRT, each fb pixel gets smeared into its neighbors
    a bit, via one or more of the above mechanisms.

    >> Just playing around in analog mode on the LCD, I see
    >> not only the pink halo on black-on-white objects, but
    >> also some ghosting (or ringing). Likely a result of the
    >> KVM switch and extra cable in that path.

    > It has to be distortion of the signal. The panel is just
    > going to sample the signal, so if there's a pink halo on
    > the screen, there's one in the signal.

    I've little doubt that the artifacts are due to the analog
    connection outside the monitor. And they probably would
    improve if I used a single shorter run of HD15 cable.

    > Maybe you just need to remove the switch and cable.

    Normally, it's only used for temporary PC connections,
    so it's not an on-going issue.

    --
    Regards, Bob Niland mailto:name@ispname.tld
    http://www.access-one.com/rjn email4rjn AT yahoo DOT com
    NOT speaking for any employer, client or Internet Service Provider.
  39. Archived from groups: comp.sys.ibm.pc.hardware.video (More info?)

    "Mxsmanic" <mxsmanic@hotmail.com> wrote in message
    news:k0kur0l41j26inl877ikc58uoqpnpi160s@4ax.com...
    > Note also that aliasing is usually a sign of lower resolution, not
    > higher resolution.
    >

    Well, no - "aliasing," if that's truly what a given observation
    is all about, is always a sign of improper sampling, whether
    it's in an analog situation or a digital one. See "Nyquist
    sampling theorem" for further details.

    The classic sort of "aliasing" in displays is the good ol'
    Moire pattern common to CRTs. What few people realize
    is that such patterns were in the past seen as GOOD things
    when a CRT maker was testing a new tube, as being able
    to see the Moire pattern was a visible indication that the
    tube was able to focus sufficiently well!

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

    "Mxsmanic" <mxsmanic@hotmail.com> wrote in message
    news:1cpur0po7frloek9q1vn306asak5ogji42@4ax.com...
    > Remember that, in theory, there's no fixed upper limit to horizontal
    > resolution on a CRT,

    No, there is ALWAYS an upper limit to the resolution of
    a CRT - for the simple reason that, even in theory, an
    infinite bandwidth channel is not possible. Any limitation
    on bandwidth in the video signal path represents a
    resolution limit. And with respect to the CRT specifically,
    other resolution limits come in due to the lower limits on the
    physical spot size and the ability of the tube to switch the
    beam on and off (i.e., you can't make a CRT without
    capacitance in the gun structure, so you can never get an
    infinitely short rise/fall time unless you can come up with a
    video amp that's a perfect voltage source, capable of
    delivering infinite current when needed).

    > although the mask or grille spacing imposes some
    > practical restrictions. So you could be seeing additional detail on the
    > CRT that the LCD cannot display, in some cases.

    And the mask or grille, along with the phosphor dot structure,
    places some very similar limits on the resolution available
    from the CRT as does the physical "pixel" structure of the
    LCD or other FPD type. (Whether or not the limits are the
    SAME for a given pixel pitch is really more a question of
    such things as whether or not the LCD in question permits
    sub-pixel addressing, which few so far do.)


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

    Bob Myers writes:

    > Possibly; we'll see how it plays out. While digital
    > interfaces are becoming a lot more popular, analog
    > connections still account for well over 80% of the
    > video actually being used in the desktop monitor
    > market, even though LCDs took over from CRTs
    > as the unit volume leader this past year.

    If my memory serves me correctly, the earliest monitor connection
    interfaces for PCs (CGA and EGA, for example) were _digital_ connection
    interfaces. VGA went "backwards" to analog to provide higher
    resolutions and color depths, and greater flexibility.

    --
    Transpose hotmail and mxsmanic in my e-mail address to reach me directly.
  42. Archived from groups: comp.sys.ibm.pc.hardware.video (More info?)

    Bob Niland writes:

    > The entire concept of "high end CRT" is already dead ...

    Not for the most critical uses. A high-end CRT is still the best image
    quality overall, if you really need the absolute best.

    CRTs also still dominate at the low end, since they are ten times
    cheaper than flat panels.

    As in so many other domains, the advantages of digital do not involve
    actual quality, but instead they involve convenience. And in the
    imaging field, the usual cost advantage of digital doesn't exist,
    either--digital imaging equipment is at least as expensive as analog
    equipment, because of the bandwidths required.

    > and increasingly what remains of new CRTs in the market
    > will tend toward junk (or be seen as so).

    CRTs are projected to be clear leaders on the market for years to come.
    Flat panels receive all the media hype, but they are not actually
    running the show. It all reminds me of the very similar situation in
    "digital" (electronic) photography vs. film photography.

    > The momentum
    > to flat panel (LCD or not) may cause the entire analog
    > graphics connection to go the way of the impact printer
    > before NAVI can get a foothold.

    Not likely any time soon. The inertia of the computer industry today is
    enormous; things no longer change over night. The VGA interface may be
    around indefinitely, and some users are still using earlier interfaces
    (which, ironically, were digital).

    --
    Transpose hotmail and mxsmanic in my e-mail address to reach me directly.
  43. Archived from groups: comp.sys.ibm.pc.hardware.video (More info?)

    > Mxsmanic <mxsmanic@hotmail.com> wrote:

    >> The entire concept of "high end CRT" is already dead ...

    From a market standpoint, I hasten to add.

    Sony, for example, has ditched all but one of
    their CRTs, most recently the GDM-FW900 24" wide,
    even though it sold for less than the 23" LCD
    that replaced it. The entire Sony entry-level,
    mid-range and hi-end consumer and business CRT
    product line is done for. Sony was selling CRTs
    using a "higher quality" positioning. The customers
    took the extra cash and spent in on LCD.

    > Not for the most critical uses. A high-end CRT
    > is still the best image quality overall, if you
    > really need the absolute best.

    And you pay dearly for that. The remaining Sony GDM-C520K
    is a $2000 product. But customers other than graphics
    professionals, who have $2K to spend, are spending
    it on LCD. The wider market for "quality" CRTs is gone.

    > CRTs also still dominate at the low end, since
    > they are ten times cheaper than flat panels.

    Not 10x. LCD prices have been collapsing. Using Wal-Mart
    as a low-end reseller, their low-end 17"LCD is only
    1.3x of their low-end 17"CRT. True, you can get into a
    CRT for $70, and their cheapest LCD is $188, but that's
    still only 2.7x.

    You can watch the Asian press lament the near-daily LCD
    pricing collapse at: <http://www.digitimes.com/>

    > As in so many other domains, the advantages of digital
    > do not involve actual quality, but instead they involve
    > convenience.

    It has ever been thus. In addition to being trendy and
    cool, LCDs are cheaper to ship, use less power, turn on
    faster, are easier to install and move around, take up
    less space and are less of a problem at disposal time.
    The small premium they still command is something an
    increasing number of average users are willing to pay.

    > CRTs are projected to be clear leaders on the market for
    > years to come.

    Only if someone is still making them.

    > It all reminds me of the very similar situation in
    > "digital" (electronic) photography vs. film photography.

    Yep. I dumped all my 35mm gear on eBay last year, went
    all-digital, and haven't regretted it for a moment.
    Silver halide is racing CRT to the exit, but both will
    be around for a while yet.

    > The VGA interface may be around indefinitely, and some
    > users are still using earlier interfaces (which,
    > ironically, were digital).

    Yep, we've come full circle to CGA and EGA :-)

    --
    Regards, Bob Niland mailto:name@ispname.tld
    http://www.access-one.com/rjn email4rjn AT yahoo DOT com
    NOT speaking for any employer, client or Internet Service Provider.
  44. Archived from groups: comp.sys.ibm.pc.hardware.video (More info?)

    Bob Niland writes:

    > Not to mention circuit bandwidth ...

    Circuit bandwidth places an even greater restriction on digital
    transmission. For any given channel speed, the real-world capacity of
    the channel is always lower for digital transmission than for analog
    transmission.

    Remember that digital transmission is nothing more than declaring an
    arbitrary signal level as a noise threshold, and considering anything
    below it as noise and anything above it as information. Inevitably,
    this reduces the information-carrying capacity of the channel.

    > ... beam spot size, beam focus and grill diffraction.

    True, but CRT manufacture is extremely mature, and amazing things can be
    done.

    There was a time when NTSC meant "never the same color," but even NTSC
    is amazingly precise these days--more so than many people would have
    ever thought possible.

    > My impression is less detail on the CRT. Each LCD triad
    > definitely represents one graphics card frame buffer pixel.
    > On the CRT, each fb pixel gets smeared into its neighbors
    > a bit, via one or more of the above mechanisms.

    The total information content on the screen is the same, though.

    Some high-end CRTs for broadcast video use have a mode that deliberately
    reduces bandwidth in order to produce a more natural-looking image
    through the filtering of high-frequency signal that bandwidth
    restriction produces. CRTs can handle extremely high resolutions if
    need be.

    --
    Transpose hotmail and mxsmanic in my e-mail address to reach me directly.
  45. Archived from groups: comp.sys.ibm.pc.hardware.video (More info?)

    Bob Myers writes:

    > No, there is ALWAYS an upper limit to the resolution of
    > a CRT - for the simple reason that, even in theory, an
    > infinite bandwidth channel is not possible.

    But I said no _fixed_ upper limit. The upper limit depends on the
    performance of all the components in the chain. Ideally it is equal to
    or better than the design limit of those components.

    So a CRT might be designed to provide x resolution, but in fact it might
    stretch to x+10% resolution. Of course, when digital elements are
    present in the chain, the extra resolution, if any, is wasted.

    --
    Transpose hotmail and mxsmanic in my e-mail address to reach me directly.
  46. Archived from groups: comp.sys.ibm.pc.hardware.video (More info?)

    Bob Myers writes:

    > Unfortunately, I'm going to have to disagree with that, as
    > well; as I noted in another response here, neither type of
    > interface, per se, is inherently superior to the other.

    But all digital systems are simply analog systems operated in a
    predefined way that declares anything below a certain threshold to be
    noise. So the capacity of a digital system is always inferior to that
    of an analog system with similar components and bandwidth.

    Furthermore, the physical interface at either end of any system is
    _always_ analog, so the system as a whole is never better than the
    analog input and output components.

    It's possible to surpass analog if you are building a system that does
    not interface with the physical world. For example, if the system
    handles _only_ information (such as accounting data), then you can
    easily surpass analog performance with digital methods. But for any
    system that requires a physical interface--audio, video, etc.--no
    digital system can ever be better than the best possible analog system.
    This is inevitable because all digital systems of this kind are just
    special cases of analog systems.

    > Both are ultimately limited by the Gospel According to
    > St. Shannon, which puts strict limits on how much data
    > you can get through a given channel REGARDLESS of
    > how that data is encoded.

    Yes. If the channel is analog, the limit of the channel's capacity is
    equal to the limit imposed by Shannon. But if the channel is digital,
    the limit on capacity is always below the theoretical limit, because you
    always declare some portion of the capacity to be noise, whether it
    actually is noise or not. This is the only way to achieve error-free
    transmission, which is the advantage of digital.

    In analog systems, there is no lower threshold for noise, but you can
    use the full capacity of the channel, in theory, and in practice you're
    limited only by the quality of your components. In digital systems, you
    declare _de jure_ that anything below a certain level is noise, so you
    sacrifice a part of the channel capacity, but in exchange for this you
    can enjoy guaranteed error-free transmission up to a certain speed.

    > That's not the only reason for this; high-end audio also
    > incorporates huge dollops of what can only be seen as
    > "religious" beliefs, with no basis in reasoning or evidence,
    > re a given individuals' views on what is "superior."

    Not necessary. Ultimately, audio systems (and imaging systems) depend
    on analog devices for input and output. So no system can ever be better
    than the best analog system. This is inevitable for any system that
    requires interfaces with the physical world, such as displays,
    microphones, speakers, etc., all of which _must_ be analog.

    The real problem with analog is not its ability to provide quality
    (which is limited only by the limits of information theory) but the
    extremely high expense and inconvenience of obtaining the best possible
    quality. Digital provides a slightly lower quality for a dramatically
    lower price.

    Just look at flat panels: they provide defect-free images at a fixed
    resolution, but they don't provide any higher resolutions. CRTs have no
    fixed upper limit on resolution, but they never provide defect-free
    images.

    > No. This is a common misconception regarding what is
    > meant by the term "analog." It does NOT necessarily mean
    > a system which is "continuous," "linear," etc., even though
    > in the most common forms of analog systems these are
    > often also true. "Analog" simply refers to a means of encoding
    > information in which one parameter is varied in a manner
    > ANALOGOUS TO (and hence the name) another - for
    > example, voltage varying in a manner analogous to the original
    > variations in brightness or sound level. The real world is
    > not "analog" - it is simply the real world. "Analog" points
    > to one means of describing real-world events, as does
    > "digital."

    Analog reduces to using the entire channel capacity to carry
    information, and tolerating the losses if the channel is not noise-free.
    Digital reduces to sacrificing part of channel capacity in order to
    guarantee lossless transmission at some speed that is below the maximum
    channel capacity. With digital, you sacrifice capacity in order to
    eliminate errors. With analog, you tolerate errors in order to gain
    capacity.

    Only analog systems can reach the actual limits of a channel in theory,
    but ironically digital systems usually do better in practice. Part of
    this arises from the fact that analog systems introduce cumulative
    errors, whereas digital systems can remain error-free over any number of
    components in a chain, as long as some of the theoretical capacity of
    the chain is sacrificed in exchange for this.

    I used to go with the "analogy" explanation for digital vs. analog, but
    since everything in reality can be seen as _either_ a digital or analog
    representation, this explanation tends to break down under close
    examination. The explanation I give above does not, and it is
    compatible with other explanations (for example, representing things
    with symbols is just another form of the arbitrary threshold for noise
    that I describe above).

    --
    Transpose hotmail and mxsmanic in my e-mail address to reach me directly.
  47. Archived from groups: comp.sys.ibm.pc.hardware.video (More info?)

    Bob Myers writes:

    > The "granularity" of the look-up table data is not the
    > limiting factor; it's the number of bits you have at the
    > input to the panel, vs. the numer of bits you claim to
    > have at the input to the overall system. If I map 8-bit
    > input data to, say, 10-bit outputs from the look up
    > table, I don't get as good a result as I want if the panel
    > itself has only 8 bits of accuracy.

    But the panel is driving analog pixels. If you get a 10-bit value from
    the LUT, why can't you just change this directly to an analog voltage
    and drive the pixels from it? You'll still be limited to 256 discrete
    luminosity levels for a pixel, but east of those levels can be chosen
    from a palette of 1024 steps between black and white. So you have more
    precise control of gamma on output. You could use more bits to make it
    even more precise.

    --
    Transpose hotmail and mxsmanic in my e-mail address to reach me directly.
  48. Archived from groups: comp.sys.ibm.pc.hardware.video (More info?)

    Bob Niland writes:

    > From a market standpoint, I hasten to add.

    Even that I wonder about. Flat panels are the rage in developed
    countries, but CRTs still have a market elsewhere, since they are so
    cheap.

    > Sony, for example, has ditched all but one of
    > their CRTs, most recently the GDM-FW900 24" wide,
    > even though it sold for less than the 23" LCD
    > that replaced it.

    I'm not sure that this was a good decision on Sony's part, but then
    again, Mr. Morita has been dead for quite a while now.

    > The entire Sony entry-level,
    > mid-range and hi-end consumer and business CRT
    > product line is done for. Sony was selling CRTs
    > using a "higher quality" positioning. The customers
    > took the extra cash and spent in on LCD.

    So all the Artisan buyers chose LCDs instead? That's hard to believe.

    > And you pay dearly for that. The remaining Sony GDM-C520K
    > is a $2000 product.

    About the same as any decent mid-range LCD. My little flat panel cost
    that much.

    > Not 10x. LCD prices have been collapsing.

    You can get CRTs for $60 or so.

    > True, you can get into a
    > CRT for $70, and their cheapest LCD is $188, but that's
    > still only 2.7x.

    For a large segment of the market, that's a lot.

    > You can watch the Asian press lament the near-daily LCD
    > pricing collapse at: <http://www.digitimes.com/>

    Why do they have a problem with it? I thought margins were small.

    > Only if someone is still making them.

    They will likely be made in Asia for quite some time. There are still
    several billion people there without monitors.

    > Yep. I dumped all my 35mm gear on eBay last year, went
    > all-digital, and haven't regretted it for a moment.

    I still shoot film.

    > Silver halide is racing CRT to the exit, but both will
    > be around for a while yet.

    The demise of CRTs has been predicted for forty years, and we are still
    waiting.

    > Yep, we've come full circle to CGA and EGA :-)

    A lot of the people making the decisions today are too young to remember
    CGA and EGA, so they think they're inventing something new.

    --
    Transpose hotmail and mxsmanic in my e-mail address to reach me directly.
  49. Archived from groups: comp.sys.ibm.pc.hardware.video (More info?)

    > Mxsmanic <mxsmanic@hotmail.com> wrote:

    > So all the Artisan buyers chose LCDs instead?

    No, the last remaining Sony CRT, the GDM-C520K,
    is an Artisan.

    > You can get CRTs for $60 or so.

    Even though CD audio media was higher priced than
    LP, and CD players were substantially higher priced
    than turntables, CD still killed LP surprisingly rapidly.
    Just because the old stuff is cheaper, and arguably
    "better", may not save it. Market forces have a
    logic of their own that isn't necessarily logical.

    > The demise of CRTs has been predicted for forty
    > years, and we are still waiting.

    Well, flat panel TV had been only ten years away
    for the last 50 years. It's here now. When the
    existing TVs in this household fail, they'll get
    replaced by something flat, for any number of
    reasons.

    Note Bob Myers observation that LCD sales eclipsed
    CRT within the last year. That's a fairly important
    event, and won't go unnoticed by industry planners.

    Curiously, I also note that Apple has entirely
    dropped CRTs from their product line. That really
    surprised me, because I'm not convinced that LCD
    is really ready yet for pre-press, broadcast DCC,
    video post and movie post (entirely apart from
    the recent user complaints about the color
    uniformity and stability of the Cinema 23).

    --
    Regards, Bob Niland mailto:name@ispname.tld
    http://www.access-one.com/rjn email4rjn AT yahoo DOT com
    NOT speaking for any employer, client or Internet Service Provider.
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