Soft proofing on monitor, is it possible?

[bebris]

Hello everyone!

I have encountered a soft proofing problem which i can't explain and hope maybe one of you could help to understand it.
I have some CMYK recipes which are not soft proofing correctly on my monitor.
For example I have C99 M60 Y5 K25 and I would like to see how it will look like when printed using "PSOuncoated_v3_FOGRA52.icc" profile.
I make a soft proof setup in Photoshop (device to simulate: "PSO Uncoated v3 (FOGRA%52)", Rendering Intent: Absolute Colorimetric, Display Options: Simulate Paper Color and Simulate Black Ink), but the color on screen is far away from color what I get on hard proof.
I know that I can check my color on a hard proof by measuring it. And my color (C99 M60 Y5 K25) converted to Lab with Absolute Colorimetric intent would be something like that L:39,49 a:-0,71 b:-25,28. I measure my hard proof and I get dE 1,2. So it is close.
I have an old Measure Tool which allow me to measure emission light/color and measuring my color from a screen I get Lab values L: 50,3 a:0,4 b:-42,7 and dE 20,5! This confirms what I see because the color on the screen is lighter than on the hard proof.
I know that this color can be displayed on my screen more precisely, because color space of a monitor is bigger than "PSOuncoated_v3_FOGRA52.icc" profile. My monitor profile is attached!
Can some soft proofing experts explain where the problem is? Why I can not proof this color correctly on my monitor? What do I do wrong?

regards
bebris

 

[Puch]

There are several factors which must be considered in your case. First and foremost: in which kind of light, in which environment do you evaluate the said color patch? Softproofing only works properly in a controlled environment, that means you have to put your color proof into a designated proof booth which outputs exactly the specified light. In the case of FOGRA 51 and especially FOGRA 52, you have to have a new kind of lighting booth, which illuminates the target with a mixture of "white" light and a bit of UV, too. This is to stimulate the OBA present in the papers.

Also: I don't really remember MeasureTool but I know it's fairly old, does it support measuring in M1 mode? Does your measuring instrument support M1 mode? Is your proof a certified one, measured by a M1 capable instrument. Was it printed on a certified (FOGRA 52 compatible) proofing paper?

IMHO softproofing the new FOGRA standards (51 and 52) successfully is way more complicated, than were the older ones (39 and 47). I wouldn't expect matching the substrate in a real-world scenario. Try switching off the paper simulation first.

 

[bebris]

Hi Puch,
Yes you are right! My evaluation environment is not right and probably is the biggest factor why I'm not having a match. I do not have a lighting booth and my rooms lighting is far away from desired...
My i1Pro is from second edition, so it can measure M1. Also my proofing paper is from CGS Oris and is certified for FOGRA52.
MeasureTool is very old software and it does not use M1. It was a CRT monitor era when MeasureTool was introduced and I don't think it knows something about LCD's.
But still I would like to have some proof (by measuring) that my monitor is showing right color. Can you suggest other software which would allow me to measure colors from my monitor?
regards
bebris

 

[Puch]

If you have an i1 Pro 2 (the black one) it is capable of measuring M1, indeed. I would suggest downloading the latest version of the offical X-Rite software included with the instrument (i1 Profiler). With that, you can calibrate your display, and on top of that, you can validate it after calibration.

When validating, you can choose the patch set of the FOGRA Media Wedge 3 (MW 3) and the target standard (in your case: FOGRA 52), and soon after you will have a detailed report regarding the performance of your monitor.

I'm sure that the validation will show a favourable state, as FOGRA 52's gamut is very small, even a basic sRGB screen can simulate it.

Evaluating the hardcopy proof: if you can't have a real light booth (which I understand, because it's so expensive and it's use is decreasing by the day), I suggest having a better lamp in your office with the Osram 950 "Color Proof" tubes. They're far from perfect, but much more affordable than the dedicated lights from Just Normlicht or GTI.

 

[mrserge]

Only remember that light tubes are becoming old quickly and you need to measure the light coming from them often. LED panels from Just will give a much more stable result that can be used in the long run.

 

[bebris]

Hi Puch,
I know I can validate my monitor, and I did it and it was OK!
But I still would like to make a measurements of colors in question from my monitor and make a comparison or assessment by my self.
Do comparison between emitted color and printed color is the same as between two printed? I can calculate dE between two printed. Or is there some different math involved?
What software nowdays allow to make emitted color measurements in CIE Lab?

regards,
bebris

 

[Puch]

I think the values are comparable, and if they're within a reasonable reach (1-2 delta E) the samples should visually match. Of course, the whole setup is only working if the lighting booth's spectra is as per the specifications, and the luminance of the display is comparable to the illumination of the hardcopy proof. That last part is the hardest to achieve.

 

[DanCaldwell]

Because of all of the above is exactly why we have built ProofCheck as a solution that handles the lighting the monitor and the software to calibrate them both to the standards. Proof Check – ICS Color

 

[Correct Color]

So, I'm curious...

Why are you chasing CMYK values in the first place?

The numbers you're using: C99 M60 Y5 K25, where did they come from? What color space? What do they represent? If you know the color space, create them in Photoshop in that colorspace, take the L*a*b* value out of the picker, and use that as your starting point.

If you don't know the original colorspace, then those numbers are really pretty useless.


Mike Adams
Correct Color

 

[bebris]

Hi Mike,
My goal was to check if soft proof on a monitor is correct, how big is dE. Those numbers are from "PSOuncoated_v3_FOGRA52.icc" colorspace. I can get Lab values out of them, that's not a problem. Problem is that soft proof on monitor is not what I think it should look like. I would like to check that by measuring CIE Lab from soft proof (monitor), but I do not know if there is a software that would let me do this in M1 mode.
regards,
bebris

 

[realaqu]

Hi Mike,
My goal was to check if soft proof on a monitor is correct, how big is dE. Those numbers are from "PSOuncoated_v3_FOGRA52.icc" colorspace. I can get Lab values out of them, that's not a problem. Problem is that soft proof on monitor is not what I think it should look like. I would like to check that by measuring CIE Lab from soft proof (monitor), but I do not know if there is a software that would let me do this in M1 mode.
regards,
bebris

get an Eizo cg series monitor for accurate color

 

[Correct Color]

Bebris,

My goal was to check if soft proof on a monitor is correct, how big is dE. Those numbers are from "PSOuncoated_v3_FOGRA52.icc" colorspace. I can get Lab values out of them, that's not a problem. Problem is that soft proof on monitor is not what I think it should look like.

Yeah. I get that.

Still, you need to start with a constant.

You say,

I know that I can check my color on a hard proof by measuring it. And my color (C99 M60 Y5 K25) converted to Lab with Absolute Colorimetric intent would be something like that L:39,49 a:-0,71 b:-25,28. I measure my hard proof and I get dE 1,2.

"Converted to L*a*b* from what? You can't do a conversion from an unknown color space.

However, since you think L* 39 a* -0.71 and b* -25.28 are close, we can use them.

Using them, my CMYK working space set to the PSOuncoated_v3_FOGRA52.icc profile, I get corresponding CMYK values of 75, 53, 9, 16.

Going back to the CMYK values you used, if I enter them using the same color space as a working space, I get L*a*b* values of 31, -4, ,-29.

So the only point of all that is if you're looking for accurate color, you can't rely on using any values if you don't know their corresponding color space.

However...

I did exactly what you did... and I got exactly the same result.

The first thing to remember about this medium in which we work is that it's a visual medium. Spectrophotometers don't buy our products, clients do.

The second thing to remember is that often times, when you're looking at a color issue or you go online to get an answer about a color issue, you'll get a lot of responses that tell you to solve your problem by looking in what I call the last 5 precent of setting up a color workflow.

It's not to say that the last 5 percent won't make a difference, but they're usually not the issue. Your issue has nothing to do with your ambient lighting conditions, or the type of measurement you made, and you'd have gotten the same results on a perfectly profiled Eizo.

Because in your case the issue is simply that the "simulate paper color" and "simulate black ink" options in Photoshop aren't all that accurate. They can be useful, but they can also not be useful. For the most part, I never use them, unless it's an oddball media, and then I just take a quick peek.

Here's just such a case.

The shift you've got here would show up on an Eizo, or in a perfectly lighting-controlled color room. It's just the way Photoshop renders that color in that particular condition. (Which has nothing to do with the gamut of your monitor, btw. Photoshop makes its render regardless of your monitor profile. Your monitor profile then makes its interpretation and displays it to you.)

Just to note though that in my case, I do this for a living. I've profiled thousands of monitors in my day. I'm working on a profiled retina MacBook Pro in a color-correct environment, and I got virtually the same result. Of course I didn't have a hard copy for comparison, but it was pretty obvious.

And I say virtually, because I could see the result on the screen. I didn't need to drag out a spectrophotometer to verify it.

And I'd offer to you that that should be your takeaway here. Too many people want to try and make this a strictly by-the-numbers business. It never will be.

Because in the end, it's not the delta e; it's what you see.

And finally, unless you have a specific reason, it's better to use Relative Colorimetric in almost all cases that don't involve proofing (to a specific device) than Absolute Colorimetric.



Mike Adams
Correct Color