35 Replies Latest reply on May 23, 2009 8:43 AM by Gernot Hoffmann

    notebook display for image editing?

    Level 1
      Hi. Is there a high-end wide-gammut notebook display for color-critical image editing ?
      What notebook would you recommend if you HAD TO recommend one ?
      thanks.
        • 1. Re: notebook display for image editing?
          Level 1
          And any experience with one of these notebooks? :

          http://markzware.com/blogs/top-5-laptops-for-displaying-color-gamut/2008/10/14/
          • 2. Re: notebook display for image editing?
            (Marco_Ugolini) Level 1
            I don't think there is such a thing as a "high-end wide-gamut notebook display for color-critical image editing". Not yet, at least.

            High-end color-critical image editing should be done using a good-quality desktop display -- well calibrated and profiled, of course.

            Calibrated and profiled laptop displays are better than nothing if you are on the road and have nothing else handy -- but at this time they are still very limited in their capabilities by very narrow viewing angles, lack of uniformity, and overall lower manufacturing quality standards, also due to compromises that allow for a lighter and more comfortably portable CPU.
            • 3. Re: notebook display for image editing?
              Level 1
              yes, this is commonplace knowledge, which was applicable for a long time. But ... as of today?
              Did you check the link? What about the Sony VAIO AW with 137% AdobeRGB coverage ?
              • 4. Re: notebook display for image editing?
                (Marco_Ugolini) Level 1
                The issue is not the gamut. It's the viewing angle plus the lack of uniformity. What do the reviews say on those?
                • 5. Re: notebook display for image editing?
                  Level 1
                  Not much unfortunately. But the press releases boast considerably increased viewing angles. Could be mere marketing of course. But on the other hand, I can't really see who would buy an expensive 137% AdobeRGB gamut display if viewing angle issues etc. make it useless for serious image editing.
                  • 6. Re: notebook display for image editing?
                    Level 1
                    Anyway, the gamut is impressive I think. It's a considerably improvement compared to the colors laptop monitors commonly were able to display.
                    • 7. Re: notebook display for image editing?
                      Gernot Hoffmann Level 3
                      Quoted:
                      "The same is true of printers which can capture a wider gamut
                      than your screen can display. More recent laptop monitors are
                      LED backlit, and while at first this was only an incremental
                      improvement, in recent months laptops have come out that can
                      actually exceed 100% of the NTSC color gamut."

                      The article is marketing nonsense. Gamuts cannot be compared
                      by percentage. Nobody else would use NTSC as a reference.

                      Best regards --Gernot Hoffmann
                      • 8. Re: notebook display for image editing?
                        Level 1
                        Gernot, you can compare Gamuts by percentage, if you display the gamuts as triangles in the CIE 1931 xy chromaticity diagram and compare the triangles' area. Of course, it's not an unproblematic and objective measurement due to the diagram's distortion in the direction of the green point, but still it gives you an idea (for example, considerably smaller than Adobe RGB, same size, or a bit larger). So I'd take the percentages as "rough measurement" ...

                        In my opinion, it's not marketing nonsense, because the reviewing person didn't favour one brand over the other. I just think that he/she doesn't truly understand the subject. For once, I think he/she confuses NTSC with AdobeRGB (which was subsequently used for all comparisons). And secondly, I think this is entirely false:

                        >HP didnt give their display quality in terms of the percentage of the gamut, but their press release did say the Elitebooks DreamColor LCD could display over 16 million colors. The Adobe RGB color gamut has approximately 16.7million colors in it, and after doing a little math were given a 96% gamut representation. Not bad at all.

                        Because in my opinion (comment I made there, awaiting moderation ... will probably never see the light of day over there):

                        >The Adobe RGB color gamut has approximately 16.7million colors in it. -> This statement is false. Adobe RGB, sRGB (and all other RGB color spaces for that matter) encompass an infinite amount of colors. The total amount of colors used by a given hardware device or software application depends on the bit depth it uses, from 1 bit (=2 colors, usually black and white) to 24bit (=16,7 Mio colors) and more (48bit, 96bit, etc.). So the calculation leading to 96% gamut representation is wrong. Because RGBcolor spaces, define (among other things), where red, green and blue are situated within the CIE Lab color space. How fine the graduation(=increments/nuances) are - and thus how many colors are used - depend on the bit depth."
                        • 9. Re: notebook display for image editing?
                          Gernot Hoffmann Level 3
                          Mark,

                          concerning the interpretation of gamuts in the chromaticity
                          diagram you are partly right.
                          Partly, because this diagram is a perspective projection
                          of the 3D color space XYZ onto a 2D plane.

                          More important (for me) is the question, which RELEVANT
                          colors are in-gamut or out-of-gamut in several color
                          spaces.
                          Relevant are IMO: all Pantone Spot colors, because these
                          are (when printed) the most vivid real world colors;
                          then the printer inks, because these define the reproduction;
                          and finally the colors of photographic targets, because
                          these were considered as relevant for real world colors
                          by color scientists.

                          Pages 15-19 here are showing the results:
                          http://www.fho-emden.de/~hoffmann/swatch16032005.pdf

                          Stroked symbols for out-of gamut, filled for in-gamut.

                          It's perhaps disappointing that vivid orange or yellow
                          is out-of-gamut for aRGB, but eventually not for printing.

                          But here comes the solution: in aRGB and even in sRGB
                          one can boost colors in Lab. From there one can convert
                          directly into CMYK.
                          This aspect was always forgotten by 'calibrationist'.
                          A quite common opinion is, that a camera has to acquire a
                          scene correctly. That's wrong (except for reproduction).
                          The image can be converted by manipulations into some-
                          thing more pleasing.

                          Best regards --Gernot Hoffmann
                          • 10. Re: notebook display for image editing?
                            Level 1
                            Hi Gernot Hoffmann


                            what this "Opti RGB" in page 15?

                            thank
                            • 11. Re: notebook display for image editing?
                              Gernot Hoffmann Level 3
                              Kokii,

                              OptiRGB is an exercise - how to define an RGB space
                              which contains almost all 'relevant' colors and which
                              has primaries which really exist as physical colors
                              (here as pure spectral colors).

                              On the contrary, ProPhoto RGB contains two of three
                              primaries which are non-existing colors (chromaticities
                              outside the horseshoe contour). Mathematically possible
                              but practically a disaster, IMO.

                              Best regards --Gernot Hoffmann
                              • 12. Re: notebook display for image editing?
                                Level 1
                                Thank you Gernot Hoffmann!
                                • 13. Re: notebook display for image editing?
                                  (Marco_Ugolini) Level 1
                                  A "disaster", uh?

                                  We'll have to tell all those fools who use ProPhoto RGB pronto, then, and let them know with no further delay that all those images that they produced from ProPhoto RGB, and thought looked beautiful, are actually horrible. Because you say so.

                                  Quick!
                                  • 14. Re: notebook display for image editing?
                                    (Marco_Ugolini) Level 1
                                    >HP didnt give their display quality in terms of the percentage of the gamut, but their press release did say the Elitebooks DreamColor LCD could display over 16 million colors. The Adobe RGB color gamut has approximately 16.7million colors in it, and after doing a little math were given a 96% gamut representation. Not bad at all.

                                    What utter nonsense. Gamut volume and bit depth are two totally separate things.

                                    It's always shocking (though no longer unusual) to see someone writing a review who understands nothing of the basics of what he is writing about. Where was this review posted? Who is this writer?

                                    Any color space, even the smallest ones, can be subdivided into a theoretically infinite number of steps depending on the bit depth used. The only limit is the processing power available. In 8-bit color spaces with 3 primaries (like RGB) you have 16.7 million [2^(8*3)], in 16 bits you have 281 trillion [2^(16*3)], and so on. None of that increases the gamut by one little tiny amount.

                                    Gamut volume, on the other hand, is the portion of human-visible color range that a given color space is capable of reproducing. The maximum possible color range is (roughly speaking) the volume of Lab, which is a device-independent color space, like XYZ or LCH and a few others. But no matter how gamut volume is expressed (by percentage or by using absolute numbers), the "number of colors" is *never* the way it's done, since it's meaningless for the reasons stated above.
                                    • 15. Re: notebook display for image editing?
                                      Ramón G Castañeda Level 4
                                      >On the contrary, ProPhoto RGB contains two of three
                                      primaries which are non-existing colors (chromaticities
                                      outside the horseshoe contour). Mathematically possible
                                      but practically a disaster, IMO.

                                      Just as Marco did in post #13, I found the above quoted statement in Prof. Hoffmann's #11 disconcerting. I hope further discussion of this is forthcoming.
                                      • 16. Re: notebook display for image editing?
                                        Gernot Hoffmann Level 3
                                        Actually, I would like to replace 'a disaster' by 'ugly':

                                        Let's have a look at the graphic on p.3 in this doc:
                                        http://www.fho-emden.de/~hoffmann/gamcomp18062006.pdf

                                        It shows the chromaticity diagram with gamut triangles for
                                        sRGB, aRGB=Adobe RGB, pRGB=ProPhoto RGB and my private
                                        color space oRGB=OptiRGB.
                                        Furtheron more than 1100 spot inks and the primary inks for
                                        CMYK ISOCoated and for my inkjet, where 'inks' means here
                                        'colors of inks on coated paper under D50'.

                                        Almost all these colors are in-gamut for the wide-gamut color
                                        space oRGB. Compared to this, pRGB seems to be far too large,
                                        which causes quantization problems, unless 16bpc is used.
                                        The primaries for green and blue are non-existing colors
                                        (mathematical constructs), and, what is less obvious, the
                                        primary for red is practically invisible because of lacking
                                        power at 700nm. 255,0,0 in pRGB should be black, but it isn't
                                        in PhS.
                                        That's what I meant by 'disaster'. So we have an RGB space
                                        where we cannot choose for only one channel 255 (or the largest
                                        value for 16 bpc). More precisely: in PhS CS2 we can choose
                                        such a value but there is no warning.
                                        Plenty colors inside the human gamut (which is not indicated
                                        in PhS) are out-of-numberspace in Lab, where a*,b* are confined
                                        between -128 and +127.
                                        In oRGB this happens as well, but only for a smaller percentage
                                        of possible colors.
                                        The doc shows on the following pages the truly exaggerated range
                                        of pRGB in Lab.

                                        This somewhat strange color space has its roots in the RIMM/ROMM
                                        concept by Kodak, as found here:
                                        Ph.Green+Lindsay MacDonal Ed.
                                        Colour Engineering
                                        Chapter 14
                                        K.Spaulding+E.Giorgianni
                                        Implementation of device-independent color at Kodak

                                        RIMM is scene-referred, ROMM is device-referred.
                                        RIMM can be considered as an RGB space between camera RAW
                                        and the ICC Profile Connection Space (PCS). Concerning the
                                        primaries and some other features it's the same as pRGB.

                                        The authors are talking about nonlinear manipulations for R'G'B'
                                        (gamma encoded) simultaneously to all channels, but without
                                        specifying these manipulations. We can imagine for instance a
                                        contrast improvement by an S-like Curve.
                                        Everybody knows, that this can cause strong color shifts,
                                        depending on the strength of the manipulation.
                                        RIMM/ROMM was optimized for minimal hue variations (as defined
                                        as deviations from straight lines in an a*,b* projection).
                                        The authors are comparing their good result with the bad result
                                        for some other nameless wide gamut space.

                                        Now, for what is it good - useful strategies ten years ago ?
                                        For nothing, because nowadays and in future manipulations of
                                        this type are done professionally in Lab.

                                        Surprisingly, the oversize of pRGB, as defined by the gamut
                                        triangle in xy, or by a volume in Lab, was not chosen so large
                                        because of the necessary gamut size but because of the hue
                                        robustness against 'luminosity' changes.

                                        Best regards --Gernot Hoffmann
                                        • 17. Re: notebook display for image editing?
                                          Level 1
                                          Hi Gernot Hoffmann

                                          It's bossible to obtain this profille (oRGB)?

                                          thank
                                          • 18. Re: notebook display for image editing?
                                            Ramón G Castañeda Level 4
                                            Well, I've carefully read Prof. Hoffmann's post and his PDF.

                                            While his description of the ProPhoto RGB space seems beyond reproach, and I have no quarrel with any of it, I still see nothing in there to explain why, in actual practice, those of us who have been advised by diverse authors to work in ProPhoto RGB, and have actually done so for years for all our digital photography work, carefully remaining in a 16-bit workflow and ever mindful of the constraints of inkjet and continuous-tone printers, should change our workflow now.

                                            My current ProPhoto RGB workflow certainly beats the results I (used to) get from my old Adobe RGB workflow, let alone the sRGB workflow required by non-pro local labs.

                                            Now, with 16-bit printing in Photoshop 11 ("CS4") on the Macintosh platform, I feel even more confident and am getting improved results. I'm impressed that Adobe gave us this advanced feature, which more than compensates for the lack of 64-bit functionality.

                                            It's good to see disaster downgraded to mere ugliness now, :), and I would welcome any corrections to my way of thinking here.

                                            There must be something I'm missing here, doubtlessly due to my own personal limitations.

                                            Any further input will be most welcome.
                                            • 19. Re: notebook display for image editing?
                                              Gernot Hoffmann Level 3
                                              Kokii,

                                              the profile is here:
                                              http://www.fho-emden.de/~hoffmann/OptiRGB.icc

                                              As already explained - an exercise. Personally,
                                              I'm doing everything either in sRGB (simple appli-
                                              cations) or AdobeRGB (high quality).
                                              Furtheron, it's always possible to improve images
                                              in Lab and CMYK.
                                              Following Dan Margulis, Professional Photoshop,
                                              optimal offset printing results are achieved by
                                              final editing in CMYK.

                                              Best regards --Gernot Hoffmann
                                              • 20. Re: notebook display for image editing?
                                                Ramón G Castañeda Level 4
                                                Aaaaaaaaaaaaah jetzt werde ich ruhig sclaffen können. :D

                                                >Following Dan Margulis, Professional Photoshop, optimal offset printing results are achieved by final editing in CMYK.

                                                None of which is remotely relevant to my workflow. I'll sleep well tonight. :)
                                                • 21. Re: notebook display for image editing?
                                                  (Marco_Ugolini) Level 1
                                                  Aaah, yes...Margulis -- the king of 700-step arcane workflows; sworn enemy of ICC color management, high-bit workflows, wide-gamut color spaces and Raw rendering too, just to cap it all off nicely with a bow. A true trailblazer...back to the stone age!

                                                  Let's just say that his "optimal" is not exactly *my* optimal. Hopefully, he'll just retire soon and thus charitably spare us any more of his bright insights, inside some "canyon" or elsewhere.
                                                  • 22. Re: notebook display for image editing?
                                                    Ramón G Castañeda Level 4
                                                    Needless to say, I'm absolutely not in the Margulis camp myself. It was a relief to read his name in connection with this perceived issue, making it a non-issue.
                                                    • 24. Re: notebook display for image editing?
                                                      (Marco_Ugolini) Level 1
                                                      You seem to be assuming that, upon conversion to ProPhoto RGB, and/or subsequent to an image edit, certain colors in the image will drift into the "imaginary" region of ProPhoto RGB and be forever lost, with dire consequences -- or "disastrous", or "ugly".

                                                      In my years as an imaging professional using fully color-managed late-binding workflows I have detected no ProPhoto RGB "misbehavior" that was so glaring that I or others noticed it.

                                                      Seems to me that your argument is informed more by Dan Margulis' own prejudices against wide-gamut RGB color spaces than by arguments whose validity I can recognize based on my own experience. I suggest that you take his "advice" with a generous grain of salt.

                                                      >RIMM can be considered as an RGB space between camera RAW and the ICC Profile Connection Space

                                                      You can say that RIMM is the intermediator between the input scene's Raw data and the ROMM/ProPhoto RGB space that one can use for output, storage and manipulation -- but it should not be implied that Raw itself is a color space.

                                                      A color space has primaries and tonal curves. Camera Raw is simply a mathematical construct for input that needs to be translated into colors usable for output. It has no defined primaries or tonal curves.

                                                      >The authors are comparing their good result with the bad result for some other nameless wide gamut space.
                                                      >Now, for what is it good - useful strategies ten years ago ? For nothing, because nowadays and in future manipulations of this type are done professionally in Lab.

                                                      That is, by Mr. Margulis and those who get lost along with him in his "canyons". Not by me or other professionals that I share knowledge with. You wish to sound as if your advice is based on widespread practice, but it's actually free advertising for someone who I have to admit is a sharp self-marketer who, on his way to dubious fame, also manages to dupe intelligent people.

                                                      >Surprisingly, the oversize of pRGB, as defined by the gamut triangle in xy, or by a volume in Lab, was not chosen so large because of the necessary gamut size but because of the hue robustness against 'luminosity' changes.

                                                      Not true. The gamut size was very much a core consideration in creating RIMM/ROMM, not secondary to what you call "hue robustness". It was a matter of finding the best compromise, among other factors, between quantization due to "out-of-locus" primaries, efficient encoding, gamut large enough to encompass real-world surface colors and suitability for storage and color/tonal manipulation.

                                                      To quote:

                                                      >ROMM RGB was designed to provide a large enough color gamut to encompass most common output devices, while simultaneously satisfying a number of other important criteria
                                                      i [described on page 2 of the PDF document cited below].
                                                      >[...] Increasing the gamut can only be achieved by trading off against correspondingly larger quantization errors. If the primaries are chosen to include the maximum possible chromaticity gamut (i.e., the entire area within the spectrum locus), a significant fraction of the color space would correspond to imaginary colors located outside that region. Therefore, in any encoding using such a color space, there would be wasted code values that would never be used in practice. This would lead to larger quantization errors in the usable part of the color space than would be obtained with different primaries defining a smaller chromaticity gamut.
                                                      b It is therefore desirable to choose primaries with a gamut that is big enough but not too big.
                                                      >[...] [T]he primaries selected for RIMM/ROMM RGB [...] encompass the gamut of real world surface colors,
                                                      b without devoting a lot of space to non-realizable colors outside the spectrum locus.

                                                      >"Reference Input/Output Medium Metric RGB Color Encodings (RIMM/ROMM RGB)"
                                                      http://www.colour.org/tc8-05/Docs/colorspace/PICS2000_RIMM-ROMM.pdf
                                                      • 25. Re: notebook display for image editing?
                                                        Gernot Hoffmann Level 3
                                                        The really important color is white - says the poet.
                                                        http://www.fho-emden.de/~hoffmann/blanco04122008.pdf

                                                        For the Spanish (and German) speaking readers.

                                                        Best regards --Gernot Hoffmann
                                                        • 26. Re: notebook display for image editing?
                                                          Ramón G Castañeda Level 4
                                                          Thank you for that. Alberti has long been one of my favorites. The translation into German is barely satisfactory, within the limits of the paradox of literary translation, namely that it is both impossible and necessary at the same time.

                                                          The painting by Monika Hoffmann is beautiful and particularly appropriate. May I ask what the relationship to Prof. Gernot Hoffman is?
                                                          • 27. Re: notebook display for image editing?
                                                            Gernot Hoffmann Level 3
                                                            Ramón,

                                                            I'm really happy that I found something where we
                                                            can agree ! Meanwhile some typos were corrected.
                                                            Please don't call me Prof. - I'm not posting as
                                                            a scientist here. Monika is my wife.
                                                            I started learning Spanish three months ago, but
                                                            I know these lyrics since many many years.
                                                            By Enzensberger's Museum der modernen Poesie and
                                                            by Paco Ibañez. At least Enzensberger's translations
                                                            are IMO pretty good (Lorca, Cancíon).
                                                            Here are some other examples, including Cancíon,
                                                            but only in Spanish:
                                                            http://www.fho-emden.de/~hoffmann/howww41a.html

                                                            Best regards --Gernot Hoffmann
                                                            • 28. Re: notebook display for image editing?
                                                              Level 1
                                                              THANK for this link Gernot Hoffmann.

                                                              I have a question to you: your profile oRBG are he good to make convert to profile euro coated?

                                                              thank
                                                              • 29. Re: notebook display for image editing?
                                                                Gernot Hoffmann Level 3
                                                                Kokii,

                                                                the gamut volumes of ISOCoated and EuroscaleCoated
                                                                are entirely inside the volume of oRGB=OptiRGB.

                                                                Nothing wrong, using oRGB, besides the fact that we
                                                                will be the only users ...
                                                                For other readers: oRGB is a wide-gamut RGB space
                                                                with spectral color primaries (real colors).

                                                                If you have ProfileMaker5 (or 4): Compare gamuts
                                                                in ProfileEditor, GamutView by different graphics.

                                                                Best regards --Gernot Hoffmann

                                                                Referring to my previous post:
                                                                not Cancíon but Canción.
                                                                • 30. Re: notebook display for image editing?
                                                                  Level 1
                                                                  Thank

                                                                  >>If you have ProfileMaker5 (or 4): Compare gamuts<<
                                                                  sorrow. i dont have...

                                                                  could you make printscreen [3d GamutView by different graphics] for me with ISOCoated and Euro scaleCoated inside oRGB between aRGB?

                                                                  i very assessor this
                                                                  • 31. Re: notebook display for image editing?
                                                                    Christian Davideck Level 1

                                                                    Gernot Hoffmann wrote:

                                                                     

                                                                    Gamuts cannot be compared
                                                                    by percentage.

                                                                    (Mark_J_Peterson) wrote:

                                                                     

                                                                    Gernot, you can compare Gamuts by percentage, if you display the gamuts as triangles in the CIE 1931 xy chromaticity diagram and compare the triangles' area. Of course, it's not an unproblematic and objective measurement due to the diagram's distortion in the direction of the green point, but still it gives you an idea

                                                                     

                                                                    Gernot Hoffmann wrote:

                                                                     

                                                                    concerning the interpretation of gamuts in the chromaticity
                                                                    diagram you are partly right.
                                                                    Partly, because this diagram is a perspective projection
                                                                    of the 3D color space XYZ onto a 2D plane.

                                                                     

                                                                    Gernot, one could also compare the real gamut volumes in 3D (as opposed to their 2D projection). Wouldn't this be a correct gamut comparison then, despite of your original statement, that gamuts cannot be compared by percentage ?

                                                                    • 32. Re: notebook display for image editing?
                                                                      Christian Davideck Level 1

                                                                      Gernot Hoffmann wrote:

                                                                       

                                                                      Actually, I would like to replace 'a disaster' by 'ugly':

                                                                      Let's have a look at the graphic on p.3 in this doc:
                                                                      http://www.fho-emden.de/~hoffmann/gamcomp18062006.pdf

                                                                      It shows the chromaticity diagram with gamut triangles for
                                                                      sRGB, aRGB=Adobe RGB, pRGB=ProPhoto RGB and my private
                                                                      color space oRGB=OptiRGB.

                                                                       

                                                                       

                                                                      Gernot, I have searched on the Internet for references to OptiRGB and didn't find anything. Could you post its specifications as shown in the table here ? http://www.brucelindbloom.com/index.html?BetaRGB.html

                                                                      I'd be particularly interested in Lab gammut efficiency and coding effeciency as defined there. In your opinion, how does optiRGB compare to the other optimized colour spaces there ?

                                                                       

                                                                      Gernot Hoffmann wrote:

                                                                       

                                                                      Plenty colors inside the human gamut (which is not indicated
                                                                      in PhS) are out-of-numberspace in Lab, where a*,b* are confined
                                                                      between -128 and +127.

                                                                       

                                                                      Hm, I always thought the opposite would be true (also suggested by the wikipedia page if I understand correctly):

                                                                       

                                                                      http://en.wikipedia.org/wiki/Lab_color_space

                                                                       

                                                                      [...] many of the “colors” within Lab space fall outside the gamut of human vision, and are therefore purely imaginary;
                                                                      • 33. Re: notebook display for image editing?
                                                                        Christian Davideck Level 1

                                                                        Gernot Hoffmann wrote:

                                                                         

                                                                        Personally,
                                                                        I'm doing everything either in sRGB (simple appli-
                                                                        cations) or AdobeRGB (high quality).

                                                                         

                                                                        For which reasons don't you use optiRGB then?

                                                                        • 34. Re: notebook display for image editing?
                                                                          Christian Davideck Level 1

                                                                          Gernot Hoffmann wrote:

                                                                           

                                                                          Nothing wrong, using oRGB, besides the fact that we
                                                                          will be the only users ...

                                                                           

                                                                          I was thinking ... does it matter at all, if we were the only users ... ? As long as we embed the profile into the files, I can't see any problem with this, right ?

                                                                          • 35. Re: notebook display for image editing?
                                                                            Gernot Hoffmann Level 3

                                                                            Christian,

                                                                             

                                                                            thanks for being interested in my stuff:

                                                                             

                                                                            The data for OptiRGB and the 2D gamut version are shown

                                                                            here, p.17:

                                                                            http://www.fho-emden.de/~hoffmann/swatch16032005.pdf

                                                                             

                                                                            The profile can be downloaded:

                                                                            http://www.fho-emden.de/~hoffmann/OptiRGB.icc

                                                                             

                                                                            It would be simple, drawing a 3D visualization:

                                                                            http://www.fho-emden.de/~hoffmann/gamshow15052009.pdf

                                                                             

                                                                            OptiRGB has been an exercise - a wide gamut RGB space

                                                                            with real, physically possible primaries.

                                                                             

                                                                            ProPhotoRGB isn't that bad - in some cases it seems to be

                                                                            a practical solution:

                                                                            I had printed page 9 of the following PDF, where the colors

                                                                            are defined by CIELab:

                                                                            http://www.fho-emden.de/~hoffmann/munsell15052009.pdf

                                                                             

                                                                            Though I'm using high end equipment (better no name, the RIP

                                                                            isn' an Adobe product), the result was not convincing.

                                                                            IMHO CIELab isn't treated as it should be.

                                                                            Then I converted the PDF by Acrobat 8 into ProPhotoRGB

                                                                            (pRGB), but without being able to assign anywhere a rendering

                                                                            intent. I think, in this case it's OK, because pRGB has

                                                                            white at D50 and they grays are reaching from L*=0 to L*=100.

                                                                            The printed result, now using pRGB as input profile in the RIP,

                                                                            with rendering intent Absolute Colorimetric on almost neutral

                                                                            paper, was considerably better.

                                                                             

                                                                            The ProPhotoRGB file, loaded by Photoshop, echoes  the correct

                                                                            Lab values - within 1 unit accuracy, despite only 8 bpc numerical

                                                                            resolution.

                                                                             

                                                                            If somebody wants to continue the discussion: I'm asking politely

                                                                            for a direct personal post via

                                                                            MyFamilyName-with2n@fho-emden.de

                                                                             

                                                                            because I don't like the new forum style.

                                                                             

                                                                            Best regards --Gernot Hoffmann