Proof profile for printing
However, I see a paradox in this concept, probably because I don't quite understand the function of viewing a specific proof profile for a particular paper in Capture One. Specifically, if an ICC profile for a particular paper on a particular printer is supposed to enable a printed result to match a properly calibrated monitor, why would the selection of different such profiles show a change on the monitor? Of course if Capture One was showing me what would happen if I applied an ICC printer profile to a specific printer for which the profile was not designed, I would expect to see the effect in the soft proof, but I doubt this is the actual case.
So, am I actually producing a soft proof by viewing the image after selecting the ICC profile (for a particular paper on a particular printer)? If, so, how do I use that soft proof when the unproofed image looks more like the print than the proofed image?
Jerry C
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The following was a very comprehensive conversation that did not make it to the new site:
Re: Proof profile for printing
by tenmangu81 » Mon Feb 10, 2020 7:22 amNN635680879799322049UL wrote:If, so, how do I use that soft proof when the unproofed image looks more like the print than the proofed image?
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Jerry C
Hi Jerry,
Do you use a calibrated display ?
Actually, the soft proof on a calibrated display gives you a very good idea of what you can expect from your printer when you select the same ICC profile in the printing window of Capture One, provided you let C1 manage the print and chose the relevant ICC profile. Roberttenmangu81
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by NN635680879799322049UL » Mon Feb 10, 2020 12:07 pmThanks, Robert.
Yes, I use a calibrated display. I let C1 manage the print and choose the correct ICC profile provided by the vendor of the paper. I do understand the soft proof is supposed to show what will appear on the print, which will never be exactly the same due to the difference between the transmitted light of the display monitor and the reflected light of the print.
The essence of my question, which I did not state explicitly, is why should the soft proof differ from one ICC profile to another on the display with respect to color? I do understand there are other parameters not controlled by the profile as defined by ICC, such as sharpening, contrast and brightness, and those would require soft proofing to predict what would appear on the print. I thought the whole idea of using a calibrated display with the correct ICC color profile was to make the color, itself, seen on the display match the color on the print. If not, the ICC profile is not doing its job.
In reading the ICC document http://www.color.org/icc32.pdf, the words contrast and brightness do not appear. Color definition is the sole purpose of the ICC profile as defined by the International Color Consortium. I expect the differences I am seeing between different selected profiles provided for different papers has information for more than color (e.g., brightness, contrast) and that is the source of the differences observed when soft proofing, along with sharpness.
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Re: Proof profile for printing
by tenmangu81 » Mon Feb 10, 2020 1:25 pmHi Jerry,
First, you are right, because prints are seen from reflected light and displays from transmitted light, a perfect match, as seen by our eyes, is not possible.
And yes again, ICC profiles are just built for color adjustments and calibration, in the L*a*b* space.Contrast, sharpness, brightness, have nothing to do with that. If you print your image with a high enough resolution (say 300 dpi), you will get a print in almost perfect agreement with what is displayed on your screen, after having adjusted these 3 adjustments with your development software. If you increase the contrast, sharpness, brightness of your picture in your development process, these adjustments will be reflected on your screen AND in your print.
And again, because printers, papers, inks, don't have the same color renderings, it is normal that changing the corresponding ICC profile will give you different soft proof colors on your screen.
The ICC profile of your screen, which is obtained from a calibration process, has of course nothing to do with the ICC profile of your printer. Both are connected to the Color Management System of your OS/system, as they are both peripherals, and the CMS transform one to the other when necessary.But maybe I don't clearly understand your question.
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Robert
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by NN635680879799322049UL » Mon Feb 10, 2020 2:32 pmRobert,
The question is this: If the ICC profile has the information that is sent to the printer to match the color seen on the display with what is seen on the print, why would soft proofing display a different color than appeared without soft proofing? I thought the idea of an ICC profile is to relieve one of the effort of correcting color for different paper characteristics.
You note, "because printers, papers, inks, don't have the same color renderings, it is normal that changing the corresponding ICC profile will give you different soft proof colors on your screen." I can see how this would give different colors on the print if you don't color correct using the ICC profile. The ICC profile is supposed to account for the differences in color produced by a specific paper, printer and ink combination. That is the point of using an ICC profile, to do the color adjustment that produces a print on a paper so that it closely matches the display.
So, if a soft proof shows a discrepancy with the color on the display without the soft proof, doesn't that mean the ICC is coming up short of its objective and that I have to manually adjust the color the ICC profile failed to correct? This would not be very helpful.
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Re: Proof profile for printing
by NN635680879799322049UL » Mon Feb 10, 2020 3:27 pmAddendum. Having done some more research, I realize my comments are based on an ideal situation where the printer can produce the full gamut of colors seen on the display. In reality, the printer gamut is limited and the soft proof reflects this. In other words, the LUT provided by the ICC profile can only approximate the colors seen on the display, limited by the gamut of the printer. When you soft proof you see the difference.
There are limits to how much you can correct for out of gamut colors. You might be able to make some corrections that make the image appear more like you prefer, but in the end if the color is out of the printer's gamut, you are not going to bring it into gamut. Unfortunately, C1 does not have a way of labeling out of gamut colors (Photoshop can show them in gray).
One thing that C1 does in the printer dialog, is to display a soft proof of the image that includes black point, and rendering intent. It would be nice if you could see these when soft proofing using the View\Proof profile\profile name dropdown.
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Re: Proof profile for printing by BeO » Mon Feb 10, 2020 5:31 pm
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NN635680879799322049UL wrote:
The question is this: If the ICC profile has the information that is sent to the printer to match the color seen on the display with what is seen on the print, why would soft proofing display a different color than appeared without soft proofing? I thought the idea of an ICC profile is to relieve one of the effort of correcting color for different paper characteristics.
Jerry C
Hi Jerry,
There is either a misunderstanding of the concept on either your side or my side, or I misundertand what you've wriiten, so ignore it then.
The ICC profile for the paper is not sent to the printer, nor is the ICC profile of your monitor sent to the printer, the printer never would be able to correct himself for what you see on screen. It is the other way round. The ICC profile tells everybody who is interested what the printer/paper CAN do, and how,. It declares its properties and capabilities, so to say. The interested party, C1 for example, can use this information to show you on screen what you can expect from the print (thats when you softproof), and you can try to adjust the variant of your image to manipulate the forseseen print result. So, it is good that the preview on screen changes if you change ICC profiles when softproffing. That's my understanding of the matter.Regarding your point that without softproof the printed results matched better what you see on screen, please consider that the ICC profile of the paper was certainly created with a certain, standarized light to judge the print, e.g. D50 in a light booth. So the question would be do you use such a light when you compare the image on screen with the print.
I am far from being an expert in this area but I read a lot, enough to say that I have more
questions than I had before reading all this stuff...
I do not print myself but use a printing service and figured out by experiencing what settings roughly work for me, e.g. I have tweaked a monitor profile manually for calibration of my monitor by comparing prints on a certain paper with my screen, using the light source shining on the print similar to the light source of the rooms where the prints usually will stick on the wall. That is a mix of changing over the day daylight and halogen or LED lights with a warme or maybe neutral 4000k color temperature. Certainly not the norm but works for me, in this scenario at least.Which means: If you have a wokflow which already works fir you without using paper/printer ICC profiles for soft proofing, why change?
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Re: Proof profile for printing by BeO » Mon Feb 10, 2020 5:38 pm
This having said, I use softproofing and exposure warning in C1 as out of gamut control, as I have found it shows me the same colors out of gamut as GIMP does, which I sometimes use (instead of Photoshop) which I no longer use, and I believe they are similar in this respect. It might have been a coincidence though.
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Re: Proof profile for printing
by tenmangu81 » Mon Feb 10, 2020 5:42 pmYes Jerry,
An ICC profile is made of a color space to which is associated a matrix used when going from a peripheral to an other (or to the CMS) in order to fit the colors in such a way they match with those measured in an "absolute way" (CIE Lab) using a spectrophotometer or a colorimeter. When color spaces don't perfectly match, there are always colors "out of gamut" for one of the space with respect to the other and you must convert one space into the other. If your source space is larger than the target, these colors "out of gamut" should be forced into the target space, and you can do that in two ways, relative or perceptive. In both ways, the colors change from one space to the other, abruptly (it means some colors
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are superimposed) or smoothly (proportionally). This is why colors are different when you choose different soft proofs.
In Capture One, the tool which is used to see if you have burnt highlights or buried shadows is also representative of what is out of gamut. Actually, it's the same, as "out of gamut" colors give you also values higher than 255. So, this tool can also be used to correct the out of gamut colors when going from your large working color space to the reduced printer color space.
Robert
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by NN635680879799322049UL » Mon Feb 10, 2020 7:39 pmBeO,
You said "...The ICC profile for the paper is not sent to the printer, nor is the ICC profile of your monitor sent to the printer." I did not think either ICC profile was sent to the printer.
I think Robert's explanation captures what I thought. I thought the ICC profile was used to adjust the image data sent from C1 to the printer so the printer would reproduce the colors accurately using the paper selected. As others have noted and I have experienced, selecting the wrong ICC profile when printing can give really ugly results. When C1 manages color, it does more than prepare a soft proof does it not? If the only use of the ICC profile was to provide you with a soft proof of what the print would look like if the color was not managed, it would be pretty useless and would require you to do the job of the color management.
Robert mentioned that changing the rendering intent will change the soft proof appearance and it does on the print preview shown in the print window. However, I cannot find a way to include rendering intent when viewing the soft proof produced by selecting View\Proof profile\name of ICC profile. You can include a lot more by creating a Process Recipe and toggling the Recipe Proofing tool, but the Process Recipe does not have a way to enter the rendering intent, either.
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Re: Proof profile for printing
by NN635680879799322049UL » Mon Feb 10, 2020 7:49 pmI have copied this post and can repost it when Capture One converts this forum to the Zendesk forum platform, tomorrow. They note that postings from today may be lost in the conversion (see notice in the Workflow section for the announcement.
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Re: Proof profile for printing
by photoGrant » Mon Feb 10, 2020 10:15 pm
ICC profiles are fundementally flawed and can lead to these sorts of confusions.
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They're supposed to be self contained and convert its input into the destination with a little self contained magic inbetween.
If it is a display profile - this can be a profile that converts rendered/raw RGB values into the closest possible match within the limitations of the gamut and characteristics of said display. Unfortunately your display has its own controls, and immediately there is already an expectation from your output for perfect hardware calibration, and a potential for a wrong profile to be applied, an old calibration or even changing the brightness. This is the fundemental problem with ICC profiles. They are a middle language to an expected hardware calibrated output *ideal*. We can get close, but we can get much closer if we skip ICC's/Graphics/Interpretations in general and feed raw values to a display that can internally convert them to the output without any middle math/interpreter. This is a tangent for a fundementally different workflow but I would start reading https://www.lightillusion.com/icc_profiles.html
If it is a printer paper icc profile - this simulates the gamut/white point/contrast of the paper in question. This is not altering your image, it is representing it as is prior (with just the display conversion), with the addition of constricting to the printer limitations.
If it is a camera icc profile - this is taking the output values of the raw sensor data and converting it to a common colour space. In reality it is a more complicated pipeline than this but try not to explore there. The end result is a file that has arbitrary ideas of colour that are now mapped to ones we all can agree on. Our common language would be AdobeRGB 1998 for eg. This doesn't have to be so, we could map the raw camera data to sRGB if we cared, or even P3, or even the very display we'd look at it from home. This would open a brand new world that the photograph/graphics world won't move to any time soon.
Idealistically a workflow would look like this;
*Profile Characterisation - INTERVIEW YOUR DEVICES POTENTIAL.So then you have all these maps that are the measured restrictions of your specific devices. Printer/Phone/TV for eg. They've been set to as neutral/uncontrolled/unprocessed as physically possible so you're really knowing Larry for who he is and not who he pretends to be. Larry the Printer might only speak 1 language with a limited vocabulary, Gary might be a polygot. So your characterisation should depend on realistic expectations. Why test Larry's ability to speak Portuguese if we know he only speaks English? You could waste your time, but you'd... be wasting your time. Typically it's wisest to characterise a display against the ideal output you're looking for. Adobe RGB 1998 for eg. Or Rec 709 if you're in Premiere Pro not Capture One
*Profile Conversions
Then you just say ok, let's apply a worst case boundry for *all* displays. I might be able to see that amazing green on my epic display, but 90% of the other folks won't, so I'd rather see it how they see it. So we adopt our device maps into new profiles that restrict/move/alter the colours of our device that were either out of gamut, or badly translated, into a now common readable colour we can all agree on. So once you've got the device and its corresponding icc profile linked, you're taking what it says is blue, and telling it to add a little less yellow then... because what it thinks is blue, is green.
So all your devices have to expect something of one another, and can't communicate that this link might be broken. How could your perfect display calibration profile possibly know that your art director turned the brightness up a few clicks whilst you were away? What affect does 'brightness' do to colour mapping? Well it's not exactly linear...
Wouldn't it be nice if you could have a display that has profiles built in converting to the very devices/printers in front of you? You could. Switch to 3D LUts! Then you don't have to worry about how any software is colour managed on your operating system.
Anyway I'll post this again https://www.lightillusion.com/icc_profiles.html - it does get deep but fundementally think of ICC profiles for printing as representative translations that aide you to make informed creative decisions without comitting to that output. Regardless they're flawed and at some point in your chain you'll get results you don't expect. It could be anything from mashing the monitor brightness to getting a batch of paper with a different white point, or the software you're using has a bug and isn't working as designed...
G
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Re: Proof profile for printing
by NN635680879799322049UL » Mon Feb 10, 2020 11:20 pm
Grant,
I want to be clear, I am not talking about anything relating to profiling a display. I am assuming it is properly calibrated. I am only referring to how a program like C1 uses an ICC profile to manage color data through its CMM sent to a printer.
You seem to be saying that the ICC profile is not used to actually adjust the image sent to the printer. I agree, the ICC profile is not program code; it is a data matrix. But, it is not there just to show you via the soft proof how it would look and I don't think that is what you mean. I expect you would agree with Lightillusion, which says, "ICC profiles do not in themselves calibrate anything. They contain measurement and information data, on which ICC compliant software acts via a CMM (Colour Management Module). It is the CMM within the graphics program that uses the data contained within a given ICC to perform image adjustments to attempt to correct for device/display calibration issues/inaccuracy."
So isn't a printer just a device and wouldn't C1's CMM use the ICC data for a printer-paper combination to render the data sent to the printer so that it looks like what is on the display? If not, why would the wrong ICC paper profile result in a bad looking print? Seems to me the ICC profile for printing on a specific paper is used by the program's CMM to do something useful other than making a soft proof approximation of the expected print.
My point was that in an ideal situation, the ICC profile information unique to the paper would be used by C1's CMM to adjust the image data sent to the printer, so that it very closely matches the display. How close depends on the capabilities and gamut of the printer. To the extent the ICC profile has the data needed to define the image characteristics for a particular paper on a particular ideal printer, the soft proof should look like the unproofed image. In the real world this does not happen and the soft proof shows the defects not seen on the unproofed image. In addition, the soft proof is an imperfect attempt to use transmitted light to simulate a reflected light medium.
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Additional posts are still on the old site. Should it become accessible, I'll post it here, since these were also informative.
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