Color Space of P.S. CS - sRGB and Monitor RGB?

Discussion in 'Photoshop' started by Stanley, Dec 13, 2004.

  1. Stanley

    Stanley Guest

    Hi all,

    I'm using photoshop CS to read and process my raw photos from a canon
    20D camera. I got some problems about the color space.

    My CS's color space is set to "sRGB-IEC61966-2.1". And there is no
    color management (monitor profile) in my system setting. (I'm using a
    Sony laptop with a LCD monitor)

    I opened these raw files by CS,resized and converted them into jpg
    files.
    Color of these jpg files looks lighter when I browsed them by Acdsee
    and Breezebrowser. But them look just like photoshop ones if I opened
    them by "windows picture and fax viewer". These files are set to RGB
    mode and no gamma correction feature is actived in Acdsee.

    If I set photoshop to "Monitor RGB - sRGB-IEC61966-2.1", and opened
    these jpg files again. The color is the same Acdsee and
    Breezebrowswer.

    Here comes the question, why these 2 "sRGB" colors are different? and
    which one is more accurate, relatively? (I perfer richer colors of
    sRGB space "north america general purpose default")

    I just want to make sure the people can see similiar(I know it's too
    far away from "same") colors as I see.

    Thanks for your help. :)

    Stanly C.
     
    Stanley, Dec 13, 2004
    #1
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  2. Stanley

    l33r0y Guest

    Sounds like Acdsee and Breezebrowswer is ignoring the colourspace
    information and using default colourspace.

    Either: convert the image to the default colour space, or make sure your
    recipients are using a image viewer that takes colourspace into
    consideration to ensure the image is being displayed correctly.
     
    l33r0y, Dec 13, 2004
    #2
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  3. Hi Stanley, since you do not have (an accurate) display profile in the
    DisplayProperties... Colormanagement -tab your system assume that your
    display is in the sadRGB color-space. No displays are in that
    color-space, especially so with flat panels since flat panels can not
    be profiled with any kind of RGB working-space ICC proflies. With flat
    panels you need a very accurate display profile.
    Aha. There should be no difference at all. The color-management is
    active but the system is specified to be in the sadRGB and your RGB
    working-space inside Photoshop is also sadRGB. No conversion should
    happen and in fact does not happen.

    However, the Adobe color-management engine (AdobeACE) does apply
    slope-limiting on the display path over the dark end of tonal
    reproduction range. This is why in your system the image appearance is
    more dark in Photoshop.

    When you set Photoshop color-management to "Monitor RGB" then in effect
    the color-management inside Photoshop is disabled so also the
    slope-limiting is disabled. And you get the very same image appearance
    that you get in other software that are not color-managed.

    With properly profiled display this particular slope-limiting on the
    display path of Photoshop gives trouble only with dark (low-key)
    images.
    There are no "richer colors of sadRGB space". Colors are what they are
    and the task of color-manamement is to keep them like that.

    When one Assign say AdobeRGB profile to the JPEGs that one get from the
    RAW converter while the conversion option was say sadRGB then of course
    colors do appear with far less saturation but this is because the
    color-management was not used correctly.
    You need a _very_ good profile for your LCD panel and still you will
    not get very good accuracy. Much better solution is to hook up a CRT
    monitor to your laptop that is then calibrated&profiled with the
    AdobeGamma. Flat panels are very difficult for color-management, their
    properties vary enormously from model to model and they are extremely
    difficult to profile acccurately.
    Timo Autiokari http://www.aim-dtp.net
     
    timo.autiokari, Dec 14, 2004
    #3
  4. Stanley,

    I forgot to mention, most if not all the laptops have the normal CRT
    socket ...and it is quite easy to find a CRT for comparison
    experiment. I warmly suggest to you such an expereiment, it is very
    useful to see this side by side.

    Hi Stanley, since you do not have (an accurate) display profile in the
    DisplayProperties... Colormanagement -tab your system assume that your
    display is in the sadRGB color-space. No displays are in that
    color-space, especially so with flat panels since flat panels can not
    be profiled with any kind of RGB working-space ICC proflies. With flat
    panels you need a very accurate display profile.
    Aha. There should be no difference at all. The color-management is
    active but the system is specified to be in the sadRGB and your RGB
    working-space inside Photoshop is also sadRGB. No conversion should
    happen and in fact does not happen.

    However, the Adobe color-management engine (AdobeACE) does apply
    slope-limiting on the display path over the dark end of tonal
    reproduction range. This is why in your system the image appearance is
    more dark in Photoshop.

    When you set Photoshop color-management to "Monitor RGB" then in
    effect the color-management inside Photoshop is disabled so also the
    slope-limiting is disabled. And you get the very same image appearance
    that you get in other software that are not color-managed.

    With properly profiled display this particular slope-limiting on the
    display path of Photoshop gives trouble only with dark (low-key)
    images.
    There are no "richer colors of sadRGB space". Colors are what they are
    and the task of color-manamement is to keep them like that.

    When one Assign say AdobeRGB profile to the JPEGs that one get from
    the RAW converter while the conversion option was say sadRGB then of
    course colors do appear with far less saturation but this is because
    the color-management was not used correctly.
    You need a _very_ good profile for your LCD panel and still you will
    not get very good accuracy. Much better solution is to hook up a CRT
    monitor to your laptop that is then calibrated&profiled with the
    AdobeGamma. Flat panels are very difficult for color-management, their
    properties vary enormously from model to model and they are extremely
    difficult to profile acccurately.

    Timo Autiokari http://www.aim-dtp.net
     
    Timo Autiokari, Dec 15, 2004
    #4
  5. Stanley

    Tiny Johnson Guest

    Tiny Johnson, Dec 16, 2004
    #5
  6. Stanley

    DeadPixel Guest

    YAY!!!
    i've been having trouble with reds and other colors for a long time. but i
    just read this and went in:

    Edit/Color Setting --> "Setting" --> (selected) --> "Color Management Off"

    now i see the colors the way i expect :D and the way they look to everyone
    who sees my photos.
    THANX!!!
     
    DeadPixel, Feb 7, 2005
    #6
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