Color Management- still sRGB for the world?

Discussion in 'Digital Darkroom' started by conrad_hoffman, Jun 6, 2021.

  1. We've been told forever to use sRGB for the web and anything the general public might have to use. Is it time to reexamine the premise, since just about everything is color managed these days? I'm not aware of any popular browser that isn't. Pretty sure common display programs are. Displays themselves are mostly sRGB, but hopefully that's changing. At least slowly. So is the rule still valid, or is it time not to be so paranoid and let some Adobe or other color space images out there?
     
  2. digitaldog

    digitaldog Andrew Rodney

    It isn't an sRGB world and the web knows nothing about sRGB or otherwise. Browsers are either color managed or they are not. Any color managed browser or other such software understand what sRGB is, just like any other tagged color space. Non color managed software have no idea what sRGB is, or the condition of your display profile; they are simply not color managed. They send the RGB numbers, as is, directly to the display.
    There are millions of non sRGB displays in the world (examine every iPhone since model 6 and iPads let alone wide gamut displays). The iOS browser and entire system is color managed with wide gamut displays, all is fine.
    Few browsers are NOT color managed thankfully.
    So this isn't a rule, it isn't valid and in fact, you can see more here:

    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:
     
  3. IMO it's not so much about colour management as about the 'average' display device out there.

    I think it's a bit optimistic to expect the majority of display devices to handle other than the limited sRGB gamut. Things are improving, but only slowly and more sideways than upwards.

    The sRGB gamut and TRC was geared toward obsolete CRT displays with their phosphors and in-built tone curve. And that's no longer what's made and what people use.

    IME the shift (literally) toward LCD and OLED displays has skewed the sRGB primaries from aligning with what most monitors natively produce.

    Sure, there are display devices available that can show nearly 100% of the AdobeRGB gamut, but the general public isn't willing to spend over $1000 to get that. While the average - even IPS - LCD display is pushed even to show over 90% of the sRGB gamut. Simply because of the above primary misalignment.

    So we can either wait and hope for the rest of the world to catch up and get wise to better quality displays. Or we can stick with the web's 'Lingua Franca' and LCD (Lowest Common Denominator) of sRGB. And to be honest, it ain't that bad. Just think back a few years to the awful standard of colour reproduction we had with half-tone offset-litho printing and the like, compared to what's seen on portable electronic devices these days.
     
  4. Andrew- thanks, I knew most of that but always pick up a few things from your videos. I'm well aware of the limitations of sRGB for printing. At the moment I'm fighting a green issue with my Canon PRO-100. I don't think there's anything wrong with my profiles or color management, I just think the printer can't cover what some of the original scene looked like, or at least how I remember it. I figure I'll fully understand this stuff about the time I'm too old to pick up a camera.

    Joe- I had to ask the question, but the LCD of sRGB seems to be serving us well and it may be a long time before most people can display any usefully larger color space.
     
  5. I, for one, don't really want my pictures to be all that full of information when displayed on the web.

    That's why I use my old Photoshop "Save for the Web and Devices" option. It not only reduces the image to sRGB, but also strips out a lot of other information when set to do so.
     
  6. digitaldog

    digitaldog Andrew Rodney

    Doesn't exist. If it did, we wouldn't need to calibrate our displays. They would all be of an average behavior. The way people futz with the OSD, the min and max NITs of each, the technology of the backlight, the contrast ratio; all prove there is no such beast as an 'average' display. And again, it is why they are profiled after calibration.
    An iPhone 6 and iPhone 12 display, an iPad, my NEC SpectraView, and the very, very old CRTs using P22 phosphors of which sRGB was defined all differ dramatically.
    No one needs to worry about a so called 'average' display. One only needs a profile that defines it's behavior and color management. And thankfully, we have color management for that.
    Tens of millions do exceed sRGB gamut; again, just the iPhones and iPads alone make up tens of millions of wide gamut displays that exceed sRGB gamut.
    Tens of millions of of the general public have wide gamut displays color managed as well.
    Tens of millions of better displays exist today.
    sRGB is going to to the way of the dodo bird as it should.
    It isn't that great and more importantly, the web doesn't know or care about sRGB or anything else. The browsers that show us the web are either color managed or they are not. Thankfully today, most are. IF you care about color appearance, you use color management (browsers or otherwise). Then any tagged RGB image from sRGB to ProPhoto RGB will preview 'correctly' thanks to color management.
    And on the process, hopefully not striping a profile which only produces RGB mystery meat. It is still possible in Photoshop to do this: Quick Export never embeds an ICC profile. Adobe needs to fix that. On wide gamut color managed systems, the assumption of sRGB for untagged images makes those images look butt ugly (because the assumption is wrong). There is no reason not to provide the scale of the RGB numbers to the web or elsewhere.
     
  7. digitaldog

    digitaldog Andrew Rodney

    Well for print, sRGB is about the worst RGB Working Space to use.
    Also keep in mine, no printer can print the full gamut of even sRGB. But many can print a lot of colors outside sRGB color gamut. We have to live with a disconnect between the simple shapes of RGB working space and the vastly more complex shapes of output color spaces to the point we're trying to fit round pegs in square holes. To do this, you need a much larger square hole. Simple matrix profiles of RGB working spaces when plotted 3 dimensionally illustrate that they reach their maximum saturation at high luminance levels. The opposite is seen with print (output) color spaces. Printers produce color by adding ink or some colorant, while working space profiles are based on building more saturation by adding more light due to the differences in subtractive and additive color models. To counter this, you need a really big RGB working space like ProPhoto RGB again due to the simple size and to fit the round peg in the bigger square hole. RGB working spaces have shapes which are simple and predictable and differ greatly from output color spaces. Then there is the issue of very dark colors of intense saturation which do occur in nature and we can capture with many devices. Many of these colors fall outside Adobe RGB (1998) and when you encode into such a color space or smaller gamut, you clip the colors to the degree that smooth gradations become solid blobs in print, again due to the dissimilar shapes and differences in how the two spaces relate to luminance. So the advantage of ProPhoto isn't only about retaining all those out-of-gamut colors it's also about maintaining the dissimilarities between them, so that you can map them into a printable color space as gradations rather than ending up as blobs. 


    Here is a link to a TIFF that I built to show the effect of the 'blobs' and lack of definition of dark but saturated colors using sRGB (Red dots) versus the same image in ProPhoto RGB (Green dots). The image was synthetic, a Granger Rainbow which contains a huge number of possible colors. You can see that the gamut of ProPhoto is larger as expected. But notice the clumping of the colored red vs. green dots in darker tones which are lower down in the plot. Both RGB working space were converted to a final output printer color space (Epson 3880 Luster).

    http://www.digitaldog.net/files/sRGBvsPro3DPlot_Granger.tif
     
  8. Definitely not trying to print from an sRGB file. I went to my RAW and made a ProPhoto RGB tiff file. Still tinkering with it to get what I remember the scene looking like, but I'm also aware of how bad color memory is.
     
  9. digitaldog

    digitaldog Andrew Rodney

    Well trying to achieve what you think you recall alone is a stretch.
    Then there are the issues of both camera and human metameric errors.
    Then there are the issues that cameras can record 'colors' we can't see (and hence not really colors so that's why the quotes) and there are colors humans can see, cameras can't record. Bottom line in trying to create what you recall and what you get:
    "Have no fear of perfection-you'll never reach it." -Salvador Dali
    And a very, very good article for photographers on rendering the print:
    http://www.lumita.com/site_media/work/whitepapers/files/pscs3_rendering_image.pdf
     
  10. Not very fast. Wide-gamut monitors cost a great deal more than monitors that can produce only the sRGB gamut. Even most of the photographers I know don't yet use wide-gamut monitors.

    I no longer print with a pro-100, but I never had problems with out of gamut greens. Not to say that it can't be a problem, but I never enountered it. sRGB is limited in the greens, but your printer is not restricted to the sRGB color space. The out of gamut problems I had when I used a pro-100 were mostly in reds, if I recall, and they were pretty infrequent. If you have Lightroom, you can softproof for the paper you are using and see whether LR gives you an out-of-gamut warning. Also, what paper are you using? Some have wider gamuts than others.
     
  11. digitaldog

    digitaldog Andrew Rodney

    First, lots of products soft proof but if you have anything in the image outside the sRGB display gamut, you can't see it. Hence the nice attributes of a wider gamut display.
    Next, the out of gamut overall, which predates soft proofing is rather useless. It treats a 1% and 90% OOG color equally with an ugly overlay. Now what do you do?
    The output profile map the OOG colors anyway and differently depending on rendering intent. Which to pick? Soft proof and pick your preferred rendering. But wait; you have an sRGB gamut display so you are back to flying more blind than soft proofing with a wider gamut display.
    Cameras and printers can deal with color that exceed any display gamut and again, no printer can print the entire sRGB gamut let alone Adobe RGB (1998) or ProPhoto RGB. There will never be a display with a ProPhoto RGB color gamut: never.

    The Out Of Gamut Overlay in Photoshop and Lightroom

    In this 25 minute video, I'll cover everything you need to know about the Out Of Gamut (OOG) overlay in Photoshop and Lightroom. You'll see why, with a rare exception, you can ignore this very old feature and still deal with out of gamut colors using modern color management tools.

    YouTube:
    High resolution: http://digitaldog.net/files/OOG_Video.mp4
     
  12. digitaldog

    digitaldog Andrew Rodney

    And reds, and blues and yellows!
    Yes, the larger difference is in the green primary but none the less, Adobe RGB (1998) is wider elsewhere and it takes a good 3D gamut map to show this:

    [​IMG]
     
  13. Right. My wording was unclear. What I meant was 'even though it's limited in the greens, which is the color giving you a problem...'
     
  14. Well, I'm doing better with my greens. Not quite what I remember but the less I tweak the color, the better it is. When I try to get it closer to what I remember, the green goes out of gamut. The result is less pleasing than just leaving it alone. Maybe a printer of the future will have an extra ink tank full of chlorophyll just for foliage.
     
  15. digitaldog

    digitaldog Andrew Rodney

    So you do or do not have a wide gamut display?
    If not, over doing an edit you can't see (and greens come to mind due to the above Gamut map), isn't effective. So you need to be careful when editing such that as you increase say Vibrance or Saturation (or HSL, targeting Green Sat), as you move a slider and the image ceases to update, STOP. You are moving colors you can't see due to display limitations. You can try working by the numbers (ideally LAB). Keep in mind, G255 in a color space like ProPhoto RGB isn't a color!
     
  16. No, my display is a decent sRGB display, but no more than that. I think you've hit the nail on the head- can't really edit what I can't see, even if I can print it. The printing loop is a bit too long and expensive to use it as a real time editing tool.
     
  17. Exactly. That's why I have a wide-gamut monitor. Unfortunately, it's not a perfect match for any given combination of my printer and a specific paper, but it lessens the problem of being out of gamut on my monitor when the color can be handled by the printer.
     
  18. But the Pro-100 already has extra green and red cartridges.

    I know you were partly joking Conrad, but that green tank is there for the very purpose of giving a better 'leaf' green. DD's explanation of subtractive dyestuffs giving greater saturation at the expense of brightness, hits the nail on the head. You can get a saturated and deep green from subtractive dyes, but not a saturated and light green. Whereas the opposite is true for additive RGB.

    The long and short of it being that a self-luminous display can't fully emulate a reflective print, and vice-versa.
     
  19. Sounds logical, but wrong! I assumed there was a green cart too, but the PRO-100 uses 8 carts as follows: black, grey, light grey, cyan, photo cyan, magenta, photo magenta and yellow. I'll mention it can do an excellent job with black and white prints, probably because of the greys. I don't know if the dyes do a better or worse job, gamut-wise, compared to pigment inks. As for permanence, I've seen no issues using quality paper and I'm not too concerned about my survivors complaining about fading.

    My monitor is a Viewsonic VP2468, which is relatively cheap and decent for sRGB. ViewSonic VP2468, 24’’ Professional Monitor The cost of wide gamut still isn't in the cards for me.
     
  20. There are some differences in gamut between the Pro 100 and the much much expensive Prograf Pro 1000 that I now use, but they're minor. Unfortunately, I no longer have the link to a formal test of this. However, when I got my Prograf, I printed the same photo on both printers. It was a photo with a lot of color, including greens. The two prints were extremely similiar. So I think you are probably looking at the wrong thing in worrying about the capabilities of the printer.
     

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