A Guide to Wide-Gamut Displays (v1.2)

Discussion in 'Video Cards & Monitors' started by Maldark, Oct 20, 2008.

  1. yaphax

    yaphax Member

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    just wondering - what happens if you use a wide gamut monitor, then set it to sRGB colour mode? Will that display colours correctly then, but lose your extra colours (that most of your programs aren't using anyway?)
     
  2. Mickatroid

    Mickatroid Member

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    I don't think so yaphax - the full sRGB pallet is still greater than most games/images etc. will expect you to be able to show.

    That said, it might make things a bit less full on for you. Give it a go
     
  3. lionman

    lionman Member

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    Great article:thumbup:

    I too would like to know this. How has win7 changed this colour problem? I'll have to give this a shot with my Philips and see how much it improves the colour reproduction...
     
  4. OP
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    Maldark

    Maldark Member

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    OK the article actually needs a bit of an update espectially since FireFox have gone and broken all their colour management in 3.5 *sadface*.

    This is exactly what the sRGB colour modes on wide gamut monitors are designed to do. They're supposed to reduce the colour space to that of the standard sRGB pallet. What the do in reality is fuck it up royal. The white balance goes way off and the colour gradients are nowhere near smooth, If manufacturers could start doing this effectively it would probably solve a lot of problems.

    Games specifically are designed with the sRGB colour pallet in mind, so should look perfect on an sRGB screen, exactly as the creators intended.

    From my experience with Windows 7 it hasn't changed a great deal since Vista. Colour management is still left up to the individual program, so some programs like microsoft picture viewer do automatically apply colour and gamut correction while most still do not.
     
  5. Mickatroid

    Mickatroid Member

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    Right you are about sRGB. I took a punt on it being 'Super' RGB but it's 'Standard'. Reason being that sRGB looks rubbish on my monitor (as you more colourfully put it :) )

    Thanks for setting this straight.
     
  6. Glieb

    Glieb New Member

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    Windows 7 does support colour management, doesn't it?

    I don't get it. In Windows 7, when I set a different ICC or ICM profile in the colour management screen as default you can see the changes immediately. And the whole screen changes and adapts to this new profile. So what does everyone mean by saying that only colour managed applications display the right colour? It changes the whole screen right?
     
  7. Mickatroid

    Mickatroid Member

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    Still getting my head around it too Glieb (it's trickier than it seems hey?) but I think the reason windows 7 'changes' is that the OS can do colour management and the supplied wallpapers contain the necessary information about the 'colour space' they were created with.

    Each application though shows its colours independently. For example I have started using Fast Picture Viewer now and again (it's a good viewer). Initially its colours were out and I had to tell it to pick up the OS's profile.

    I bought a Spyder 3 Express - very good indeed. The change is very subtle but pictures become so much more real looking.
     
  8. Glieb

    Glieb New Member

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    As I understand it, both image files and devices may contain colour profiles. Windows treats anything without a profile as being sRGB.

    Without colour management (that is, no ICC profiles in your 'Colour Management' dialog), if you have a regular gamut monitor (sRGB) and view sRGB images, then it should look alright. But if you view a wide gamut picture, it would look washed out, because the colours' intensity is shifted down on the bit level within the image file. Otherwise, if you have a wide gamut monitor, you get oversaturated sRGB images. See examples here: http://www.color.org/version4html.xalter
    http://www.gballard.net/psd/go_live_page_profile/embeddedJPEGprofiles.html

    So that's where the OS steps in, cause it has a callibrated (ICC) profile attached which specifies exactly the gamut of your monitor. Now everything on screen has to be converted to the gamut of the monitor according to this profile. But how does that work in Windows 7? Which process actually performs the colour conversion? I see two possibilities:

    1. Every application's visual elements on screen are tagged with its profile (or not, in which case it's assumed sRGB) and Windows takes the raw image bits and performs the conversion for every element separately.

    2. The application itself (Firefox, Photoshop, the Windows interface explorer.exe, Photo viewer, MS Paint, etc), aware of the gamut of their tagged images, perform the colour conversion themself. For this they have to either query Windows's active monitor profile or have the same profile attached by the user.

    I'm guessing #2 is correct as it would explain why non colour managed applications have off colours on wide gamut monitors. So the 'Colour Management' configuration dialog screen is just for applications that conform to the Windows standard of colour conversion and perform the conversion with the rendering intent that is set in that screen, along with other options.

    But what I don't understand is why the whole screen shows a change, even inside non colour aware applications, like Internet Explorer, or the non picture elements of Firefox.


    Two more OS specific things: when changing profiles, sometimes colour changes are not immediate and you have to press the 'Callibrate display' button.
    It says here that Vista isn't colour aware, but Windows 7 may:
    http://www.artstorm.net/journal/2009/07/color-management-wide-gamut-dell-2408/
    I also read somewhere that Windows XP is only partly colour managed?
     
    Last edited: Jul 7, 2010
  9. Mickatroid

    Mickatroid Member

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    You are right, they do - an I think 2 is correct. Hmm, they must ask the OS what those colours need to be. I guess that is how themes etc. work. I think many aspects of applications are drawn using os DLL files for example. Gotta say though, I am hypothesising here. ;)

    Good links, thanks. My firefox is doing version 2 (I think I installed an addon for it at some stage) but IE shows no colour managments (win 7 x64 pro).
     
  10. Glieb

    Glieb New Member

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    Yes, I know, it displays the wrong colour. But as I explained above, it does change colour, as you can visually see it become a different colour when you change ICC profiles. So... what does it do?
     
  11. Mickatroid

    Mickatroid Member

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    LOL you are right, it does for me too and I masked my screen a bit just in case it was a relative thing. Perhaps it is what happens when you apply colour correction to a non icc tagged image? This is one thread that I think might be better if I butt out. :o

    At very least I am going away to do some more reading :) I have a suspicion too that the spyder software is not playing the game quite in the same way that simply using the profile under windows does. That might require some experimentation.

    Will get back to this eventually. Thanks for the links to test ideas on.
     
  12. OP
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    Maldark

    Maldark Member

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    The colour change when you apply your monitors profile in the Colour Management screen in Windows 7 is the result of the adjusted gamma curves and colour gradients. That is it applies corrections to ensure a smooth response over the range of colours. What it doesn't do is apply gamut correction which is required for wide-gamut monitors. So your colours are now "calibrated" but they are still oversaturated.

    It's actually really easy to notice if you've got dual monitors like I do. My shiny Dell 2408WFP is wide-gamut and my Viewsonic VX2025 is a perfect sRGB monitor. When I apply my monitor profiles both screens change colour slightly, but the Dell is still clearly oversaturated.
     
    Last edited: Jul 14, 2010
  13. Glieb

    Glieb New Member

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    Aha, so it is just the gamma curves and colour gradients then. But wait, you mean that Windows 7 Colour Management cannot actually adapt the output colour gamut per screen element to the display at all? It's merely some overall tuning for the whole screen...? Then what's the point of this? If everything on the screen is changed according to the same colour scaler, then what colour are programs expected to deliver?

    If that is the case – that Windows Colour Management is not sufficient for every program because it changes the overall colour gradient, i.e. also everything that should be sRGB – then it doesn’t make sense. If people put in their ICC profile in there and also in e.g. photoshop, then that program’s output is ‘calibrated’ twice. Doesn't that over compensate?

    The only ‘benefit’ I see of using a ‘screen wide colour manager’ would be that theoretically you should be able to make everything on screen sRGB if not already and then use Windows Colour Management to de-intensify the colours to suite your wide gamut monitor. Only then you wouldn’t use the wide gamut capability of the monitor, you would just simulate sRGB like that option on the thing itself does.

    BTW I don't own a wide gamut display, but it's just that I want to know these things because I want to buy one someday. I've been reading up on colour vision in general (about rods and cones, trichromatic theory and the CIE 1931 color space and how that all translates to the primary colours used in your monitor to give you the right colour perception provided you calibrate well) but now that I want to see it work in practice I come across these peculiarities.

    Does anyone have a link for reading up on the practical (Windows) side of things (for me and Mickatroid :)) These things are hard to grasp. I just don't want to blindly install ICC profiles everywhere and assume it's calibrated well. Colour is a very subjective thing. At least we should know what is happening behind the screen (pun intended) exactly.
     
  14. OP
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    Maldark

    Maldark Member

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    I'll be the first to admit the entire colour management system needs to be rethought, it just doesn't help in a lot of situations. A lot of the problems comes from Windows not knowing what colour space any given program is running in (even though 99% will be using sRGB). Because of this it can't just blanketly apply gamut correction, it will however apply gamma correction producing a smooth colour response curve. When you load up your colour profiles in programs like photoshop, I believe (and please correct me if anyone knows better). That only the gamut information is extracted to correct for the oversized colour space on the wide-gamut monitors. The gamma corrections are not reapplied, so you do end up with the correct colour space and a smooth colour response.
     
    Last edited: Jul 17, 2010
  15. Mickatroid

    Mickatroid Member

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    :) Yes please.

    One thing I can say for sure Glieb is that having a Spyder 3 Express and a HP LP2475w monitor (factory refurbished through grays online) if everything is set up right it's obvious to the eye. Any lingering doubts can be dispelled by using paper profiles and a good printer (I have a Pixma 970 which is good enough).

    For example, I updated by Canon DPP software the other day and it turned off the option to pick up the monitor profile in the process. Some time later I opened an image of our son and found, to my surprise, I had to reduce the saturation one step (Camera RAW) when setting up to print.

    The print was washed out. The very next thing I did was check that the Spyder ICC profile was being used - it wasn't. Pretty amazing that I have gotten that used to simply getting the colours right on screen and then printing hey? Being able to do this confidently has made for consistently good prints.

    I even hold picture frames and matts up to the monitor to see if the white balance needs a little bump to suit the frame.

    Good to hear about your interest in the retina. I tutored perception for Psych students at Newcastle Uni for a while. It's interesting stuff. Also had a colleague who was into seasonal effective disorder (worth a look).

    Finally, I don't know if you ever did much film photography but you were kinda stuck with the white balance you shot (lens filters were the only real option). After a while I could see colour casts wherever I was and to some extent still do. I love halogen lamps but am not so fond of downlights - I recently noticed that you can get energy saver bulbs that look like a normal globe but have a second glass halogen light inside. Cheery halogen wherever I need it!

    PS: Am reading this http://www.artstorm.net/journal/2009/07/color-management-wide-gamut-dell-2408/
     
    Last edited: Jul 17, 2010
  16. JJJ211

    JJJ211 (Banned or Deleted)

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    Anyone have the colour profiles for the dell 3007wfp-hc (a02) and the dell 3007wfp (a04) or can point me in a direction where i can download them??? from day one i haven't been able to properly calibrate these monitors... the colours, although looking great out of the box, seem 'off' and inaccurate when viewing movies and games for some reason and i know there's headroom for improvement... especially the 'HC' version!
     
    Last edited: Aug 3, 2010
  17. Mickatroid

    Mickatroid Member

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  18. Frontl1ne

    Frontl1ne Member

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    Do people still look at this thread :p

    I have a Spyder2Express and have read that it may not provide accurate colour calibration for wide gamut monitors. I've noticed that the Spyder4Express supports wide gamut monitors.

    Just wondering, is it worth it getting a calibrator that can do wide gamut? Or is the difference not very noticeable?
     
  19. Mickatroid

    Mickatroid Member

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    This is surprising, where did you read it? I think it is doing a first rate job of my wide gamut display (HP LP2475W)
     
  20. Frontl1ne

    Frontl1ne Member

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    It's all over google, here's one example:

    http://photo.net/digital-darkroom-forum/00RUHP

    I think it does quite a good job on my U2711 as well, but then again I've never seen a well calibrated monitor in my life.
     

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