[argyllcms] Re: Can we control the shadows (was black point compensation)

  • From: Yves Gauvreau <gauvreau-yves@xxxxxxxxxxx>
  • To: argyllcms@xxxxxxxxxxxxx
  • Date: Mon, 16 Dec 2019 06:30:52 -0500

Roger and Alan,

@Roger effectively, my instrument doesn't have a polarizing filter (M3)

@Alan see below


Is there a way, using our non M3 instrument and Argyll tools to create profiles that would result in a response curve with a higher slope in the deep shadows like OEM M3 profiles shown in figure 79 and 80? If someone knows, please let me know, thanks.

Regards,
Yves


On 12/15/2019 7:34 PM, Alan Goldhammer (Redacted sender agoldhammer for DMARC) wrote:


I believe only the newer professional spectros from X-Rite have polarizing filters and are able to read M3.   There was an exceptionally long thread on the use of this approach to profiling matte papers on the Luminous Landscape forum.  I posted this link a while back on this thread but will repeat it here: https://forum.luminous-landscape.com/index.php?topic=118349.0 There are profile results from a number of people on this thread.  I also believe that Graeme commented on this at one point but don’t remember which thread it was on.  Chromix did the profiling for this paper using M3 measurements but I don’t know what software was used to create the profile. The gamut of that profile is huge, the highest for a matte paper I’ve ever seen and I have no idea what that means since my own profile using Argyll was much smaller.  In looking at test prints using the Red River profile and my own Argyll profile I see little difference.

All this is true or should I say, according to the article, using a non M3 instrument you'll never get the same numbers. A site wide search on www.argyllcms.com doesn't return any results for M3.

Using Argyll I generate very nice profiles with low reading error rates. Profiles look smooth when viewed using appropriate tools and test prints as well as prints for show or sale are all very good.  This thread on printing with matte papers is very useful: https://www.dpreview.com/forums/post/63380831 See especially the posts from Mark McCormick who in addition to be a fine printer does the best research on print permanence over at the Aardenburg.  The key to getting good results especial in the mid range where things are critical is doing good soft proofing.  Because matte papers do not have the same gamut of gloss paper, the range can be compressed and you need to solve that issue.  I have been soft proofing in PS and LR ever since the feature was added and careful work here saves a lot of paper in the end.

For me this is as obvious as the nose in the middle of our faces, in the article I referred to below, if you look at figure 79 and or 80 in both cases, the OEM M3 profile present a stronger if not a much stronger slope left part of the graph then what can be achieve with non M3 instrument profiles. Higher slope, higher contrast or higher tonal separation, that's what is needed to bring the max tonal separation in the deep shadow, at least, I would think so.

Is there a way, using our non M3 instrument and Argyll tools to create profiles that would result in a response curve with a higher slope like shown in figure 79 and 80? If someone knows, please let me know.

Test prints can only go so far.  You really need to work with images that you have photographed to see how you can bring out the best in shadow details.  It takes some work but good soft proofing is key to solving things.

"Test prints can only go so far", yes this is also true. Unfortunately, we can't do most of this for others prints, I print for others. I would say that trying to improve deep shadow details using a profile that as a fairly flat response in the deep shadow, is like rowing against the current, wouldn't you agree?


Alan

*From:* argyllcms-bounce@xxxxxxxxxxxxx [mailto:argyllcms-bounce@xxxxxxxxxxxxx] *On Behalf Of *graxx@xxxxxxxxxxxx
*Sent:* Sunday, December 15, 2019 6:33 PM
*To:* argyllcms@xxxxxxxxxxxxx
*Subject:* [argyllcms] Re: Can we control the shadows (was black point compensation)

Yves,

M3 refers to the use of a polarizing filter during measurements.

Your ColorMunki does not have a selectable polarizing filter, does it?

/ Roger

*From:* argyllcms-bounce@xxxxxxxxxxxxx <mailto:argyllcms-bounce@xxxxxxxxxxxxx> <argyllcms-bounce@xxxxxxxxxxxxx <mailto:argyllcms-bounce@xxxxxxxxxxxxx>> *On Behalf Of *Yves Gauvreau
*Sent:* December 15, 2019 5:40 PM
*To:* argyllcms@xxxxxxxxxxxxx <mailto:argyllcms@xxxxxxxxxxxxx>
*Subject:* [argyllcms] Re: Can we control the shadows (was black point compensation)

Roger,

I found something interesting here (https://luminous-landscape.com/red-river-palo-duro-softgloss-palo-duro-etching-san-gabriel-baryta-paper-review/). The M3 filter is both the culprit and the savior here as it is explained in the article.

From this article whatever I get without using this M3 filter won't be satisfactory. Because it's very likely neither of us will have one these spectro with an M3 anytime soon, we need to trust that the M3 profile will give us better prints for normal real world images then we could get from a regular non M3 profile.

It answer indirectly my question as well, the target patches we use, the measurement we make of them, the degree of smoothness we use, etc. all of this contribute to the final results. In the article the author speaks of deep shadow detail

"We still need to look at the question of deep shadow detail using the 30 Neutrals test. Recall, this test is looking for the extent of tonal separation in the deep quarter-tones from L*1 to L*30, which is graphically indicated by the closeness of fit between the red line for the measured values relative to the linear black line, which is a 45 degree trajectory with a slope of 1.0 meaning a 1L* rise of output [from the printer] relative to a 1L* rise of input [from the so-constructed test image file])."

It's good to know, we may have a test to evaluate deep shadows, but what do we do the results? I think the terminology I was looking for is "tonal separation" , I thought using black point compensation would improve this tonal separation.

Yves

On 12/15/2019 4:30 PM, graxx@xxxxxxxxxxxx <mailto:graxx@xxxxxxxxxxxx> wrote:

    Yves,

    I took a look at your profile " RR_PaloDuroSGR_PRO1000.icm" in Photoshop.

    I created a new RGB document with Black background, and assigned your

    profile to the document. In Color Settings, under Conversion Options, I

    selected Absolute Colorimetric.

    Then I placed the ColorPicker on the background and got Lab = 0,0,0.

    That does not make sense? No device in the world can give you that

    measurement value, it's impossible.

    That is why I strongly suggest that you obtain the CIE Lab value for

    "Black".

    Know what you are dealing with before you conclude anything about the

    relationship between the monitor appearance and the print appearance.

    Can you send me the ti3 file?

    / Roger

    -----Original Message-----

    From:argyllcms-bounce@freelistsorg  <mailto:argyllcms-bounce@xxxxxxxxxxxxx>  
<argyllcms-bounce@xxxxxxxxxxxxx>  <mailto:argyllcms-bounce@xxxxxxxxxxxxx>  On

    Behalf Of Yves Gauvreau

    Sent: December 15, 2019 3:32 PM

    To:argyllcms@xxxxxxxxxxxxx  <mailto:argyllcms@xxxxxxxxxxxxx>

    Subject: [argyllcms] Re: Can we control the shadows (was black point

    compensation)

    Roger,

    I can of course print and measure whatever patches out there but how will

    this help in creating a better profile especially to exploit as much as

    possible the finest of details in the deep shadows?

    Maybe it's written there in plain site but I just don't understand the

    meaning, it wouldn't be the first time.

    Thanks,

    Yves

    On 12/15/2019 10:39 AM,graxx@xxxxxxxxxxxx  <mailto:graxx@xxxxxxxxxxxx>  
wrote:

        Yves,

        Do yourself a favor to "analyze" the paper measurements.

        Look at the ti3 file "numbers".

        Or, at least, print a grayscale that goes from 255,255,255 to 0,0,0 in

        10 increments, let's say, on your paper and measure each printed

        patch, to see what kind of Lightness value (L*) you get? A good,

        coated paper will give you L* < 15. Newsprint paper is usually no lower

    than 28 to 30.

        What value are you getting on your print for the darkest black?

    Yes I can do all of this but can I use the measure to improve the profile so

    these deep shadows look much more like what I see on screen?

        / Roger

        -----Original Message-----

From:argyllcms-bounce@freelistsorg <mailto:argyllcms-bounce@xxxxxxxxxxxxx> <argyllcms-bounce@xxxxxxxxxxxxx> <mailto:argyllcms-bounce@xxxxxxxxxxxxx>
        On Behalf Of Yves Gauvreau

        Sent: December 15, 2019 7:38 AM

        To:argyllcms@xxxxxxxxxxxxx  <mailto:argyllcms@xxxxxxxxxxxxx>

        Subject: [argyllcms] Can we control the shadows (was black point

        compensation)

        Roger,

        I'm sure the way I said this is likely not the best way.

        I understand there is a physical limit to how "black" we can get from

        this or that paper, inks and printer combination. The same goes for

        the whitest value we can get, these are physicals limitations.

        If you compare the 2 region on the bottom of this image as seen on

        screen with a print of this same image on most paper, at least all the

        ones I used with very few exception.

        (http://www.jirvana.com/printer_tests/PrinterEvaluationImage_V002.zip)

        The highlights squares of value 254 to 243 on a white (255) background

        always print such that they appear very similar to what's on screen.

        With my old eyes, except for the patch 254 I can always see from 253

        to

        243 easily just as on screen.

        On the other side, the black patches on a black (0) background what I

        can see on the print is very dependent on the paper I used. On a photo

        rag satin paper by Hahnemuehle which uses my printer matte black ink,

        I get basically what I see on my screen, again with my old eyes I can

        see down to patch number 6. With some other paper I can see a

        difference only from patch number 18.

        My question, is there a way to create a profile that would better 
"render"

        the deep shadows of this image so most if not all papers look more

        like what's on my screen. Just in case it helps this especially for

        non glossy paper for which I don't care much even if they are in

        general better at this deep shadow stuff.

        Is it a question of increasing the number of patches in the deep 
shadows?

        Is it a question of the quality of the measures?

        Any suggestion?

        Thanks,

        Yves

        On 12/13/2019 6:20 PM,graxx@xxxxxxxxxxxx  <mailto:graxx@xxxxxxxxxxxx>  
wrote:

            Doesn't it "depend" on the paper, Yves?

            Some papers "absorb" more than others?

            And even though the printer adds more ink, it is only "absorbed"?

            And you don't extra "Extra L*" for it? (L* does not go down?)

            / Roger

            -----Original Message-----

From:argyllcms-bounce@freelistsorg <mailto:argyllcms-bounce@xxxxxxxxxxxxx> <argyllcms-bounce@xxxxxxxxxxxxx> <mailto:argyllcms-bounce@xxxxxxxxxxxxx>
            On Behalf Of Yves Gauvreau

            Sent: December 13, 2019 6:17 PM

            To:argyllcms@xxxxxxxxxxxxx  <mailto:argyllcms@xxxxxxxxxxxxx>

            Subject: [argyllcms] black point compensation

            Hi,

            I'm trying to choose some fine art papers. I always print de same

            image I got from here

            
(http://www.jirvana.com/printer_tests/PrinterEvaluationImage_V002.zip

            ) so I can compare apple with apple hopefully.

            Many fine art papers have a black point of around L* 16 but with 
some

            I can see many squares in the bottom left, with one I have, I can 
see

            down to square 6 while other with a similar black point value if not

            identical, I can only see down to square 16-18.

            It's all over the place basically, so my question is, can we can do

            something about that? On most if not all my prints with this image I

            can see up to square 253 almost all the time. Would be nice to have

            similar on the dark side.

            Thanks,

            Yves

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