Colorspace Confusion is Killing Me

Discussion in 'Digital Darkroom' started by nicholas_riggs, Mar 30, 2017.

  1. I've uploaded three versions of the same photo to Imgur here http://imgur.com/a/yUN0i, and while the results didn't exactly surprise me (because I'm used to not being able to figure this out), my results seem to be pointing me down the road of inconsistency, and counter-intuitively to boot.

    Basically my out-of-the-camera images "tagged" as sRGB are displaying fine in %99 of the places that I'd like them to - as are my images that are saved WITHOUT sRGB color profiles. It's my photos that are saved from Photoshop with sRGB IEC 61966-2.1 that are having a lower chance of displaying properly on my monitor.

    Here - http://imgur.com/gallery/Qt9iz - a gallery of coins I shot (especially the pennies) look like ass on Imgur, but previewed in a Dropbox folder here - https://www.dropbox.com/sh/bct00iop9dbv7kj/AAAi0_Whmysfq9ot76sOdME6a?dl=0, they look good.

    I am confused.
     
  2. Hi nicholas - The images on imgur are not sRGB yet rather Adobe RGB. If viewed on a non-color managed application/browser with an ~sRGB gamut monitor, they the saturation will look dull.
    I don't know for sure yet that seems like a fair chance for your issue.
     
  3. Keep in mind many browsers do not enable color management by default on PC, or at least that used to be the case. Also, websites to which you upload images often process them and strip out metadata like color profile and color space tags when resizing them for thumbnails and the like. From what I can tell tagging images with color space is nowhere near as effective in web browsers as including the profile. Also, both sets of images look the same on my little chromebook here, some tests online indicate it has color management fully enabled. That means your images do retain color profiles (embedded or just tagged I'm not sure) and possibly your browser doesn't have color management enabled.

    You should probably not depend on everyone having a color-managed browser yet and should continue to save all web-bound images to sRGB. Maybe make separate pages with high-gamut images if you need to show off your colors.
     
  4. This is all really simple. IF you have any document, it must have an embedded ICC profile or the software doesn’t have any idea what the scale of the numbers mean! And it will preview view the numbers incorrectly! In addition, the software MUST be ICC aware. And the image must have an embedded ICC profile. If so (and there’s nothing wrong elsewhere), every sRGB or Adobe RGB or ProPhoto RGB image with an embedded profile will preview correctly and the same in all resulting ICC aware applications on one system. IF one is ICC aware but the other application isn’t, the image (with or without an embedded profile) there will be a mismatch visually.

    NO Steven, many web browsers do totally follow color management correctly! Safari is one such example. Using sRGB alone doesn’t guarantee a visual, correct match (preview). We need color management for that; always!

    sRGB urban legend & myths Part 2

    In this 17 minute video, I'll discuss some more sRGB misinformation and cover:
    When to use sRGB and what to expect on the web and mobile devices
    How sRGB doesn't insure a visual match without color management, how to check
    The downsides of an all sRGB workflow
    sRGB's color gamut vs. "professional" output devices
    The future of sRGB and wide gamut display technology
    Photo print labs that demand sRGB for output

    High resolution: http://digitaldog.net/files/sRGBMythsPart2.mp4
    Low resolution on YouTube:
     
    dcstep likes this.
  5. In my experience it's easy to get a confict of colour spaces in Adobe Photoshop. I ended up turning PS colour management off completely and relying on the built-in computer colour profiles, along with using an sRGB calibrated monitor. I believe that PS doesn't interrogate the operating system properly for any other profiles in operation.

    I began to mistrust Adobe's grasp of colour management years ago when their monitor profiling applet (Adobe Gamma IIRC?) proved to be seriously flawed and out by a country mile.

    From published specs it seems that there's very little difference between AdobeRGB and sRGB. The green reference is more saturated (further from the white point) and the 2.2 gamma curve has no false linear portion in the extreme shadows. Apart from that it's pretty much the same as sRGB.

    The extended green/cyan area of the AdobeRGB space can be shown on very few monitors, therefore it's pretty much useless for general web use.

    And then there's the fact that the majority of web users neither know nor care about colour spaces and could far less be bothered to calibrate their viewing devices.
     
  6. Rodeo, you are confusing color management, monitor profiles and color space. Color space is nothing more than a specification which relates numbers in the digital image file to a particular color. Monitor profiles relate those colors to the colors displayed on the screen, a multi-dimensional correction factor between theory (the image) and practice (the display). Color management is the scheme by which those aspects are related.

    It is immaterial whether only a few "web users" know how to manage color I doubt many can calculate a cube root of a number by hand either (or square root for that matter), much less vector analysis (the theory behind color management). Fortunately you don't have to know how color management works in order to make it work for you.

    There is a considerable difference between AdobeRGB and sRGB, but if color management is in place you will probably not see it. That's why it's called "management" and not something else. I find that those who need to know color management are well aware of its parameters and control. These include knowledgeable photographers, illustrators, art directors and service bureaus. They're the ones who get the job done efficiently. Those not "in the know" are resigned to complaining about the poor service they receive.

    Out of gamut areas can get ugly, but are seldom seen because few real-life images approach those limits. If you are curious, Photoshop can highlight those areas in a completely unsubtle manner. I think monitors and graphics cards have improved too. I haven't been limited to 24 bits for over a decade, and I understand that the iMac Retina display in front of me now has a better-than AdobeRGB gamut. It is also calibrated (X-Rite Display) on a monthly basis.
     
  7. That isn’t possible! Nor at all desirable IF you could (you can’t turn off color management in Photoshop).
    Further, sRGB without color management isn’t at all useful nor does it guarantee a visual match WITH color management! WATCH the video!
     
  8. You think, from raw? Now a video you need to view that illustrates that all kinds of images (from raw) fall outside the gamut of Adobe RGB (1998) and sRGB, often by a lot!
    Everything you thought you wanted to know about color gamut

    A pretty exhaustive 37 minute video examining the color gamut of RGB working spaces, images and output color spaces. All plotted in 2D and 3D to illustrate color gamut.

    High resolution: http://digitaldog.net/files/ColorGamut.mov
    Low Res (YouTube):
     

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