Is there a way to calibrate(adapter LUT) a monitor from IT8, with a camera?

[Hale_JP]

Windows, starting from Vista, can use a monitor Profile as a source for graphics-board LUT-based calibration in working space.
I.e. you don't have to provide an ICC to photoshop, just work in sRGB(for instance), and add that ICC to the monitor section in Windows Color Management Engine. Don't forget to turn "calibrate monitor" checkbox "on", and push a "reload" button.

previously I was using RGB-balancing visual-pattern based calibration tools. But those are far from perfect and fail, when Windows 10(Intel GPU driver) starts tweaking gamma out of the blue. So with adjusted gamma the fishnet balance gets wrong, and colors are unpredictable.

Now I got Wolfs IT8.

So my idea is calibrating my Canon 100D camera under fluorescent lamp light (a bunch of lamps at all directions as improvised sophites). As an alternative, I think about white LED lamps, because those are closer to modern LCD backlight.

Then get a printer-like test pattern on screen, shoot it with CANON, and generate a monitor profile...

I just don't have an Idea how should I make it in Argyll, because brightness is an arbitrary value when making photos...

[TonyW]

Windows, starting from Vista, can use a monitor Profile as a source for graphics-board LUT-based calibration in working space.
I.e. you don't have to provide an ICC to photoshop, just work in sRGB(for instance), and add that ICC to the monitor section in Windows Color Management Engine......

I think you may have misunderstood how Windows colour management works and its relationship to colour savvy applications such as Photoshop.

It is quite correct to say that Windows can use a monitor profile and in fact it should have a profile that accurately describes the state of your monitor against your chosen standards.  With this in place and enabled in Windows and importantly selected your colour savvy applications will work correctly.

The monitor profile will not be sRGB so the sRGB profile in your Windows system should not be used.  You will need to use a calibrator such as X Rite or Datacolor Spyder to calibrate and profile your monitor.

EDIT:  BTW you should be making sure that the calibrate monitor checkbox is turned OFF you will not use this part of Windows.  Instead in Devices tab you should make sure that your newly created monitor profiles appear as default and the use my profile box checked - see attached

You cannot use a camera to calibrate and produce an ICC monitor profile - at least as far as I know 

[Hale_JP]

I think you may have misunderstood how Windows colour management works and its relationship to colour savvy applications such as Photoshop.

I guess, you just missed this feature in post-XP Windows. Most people think that it is the ez-"calibration" tool in windows, but actually the tool creates ICM, which is used for GPU-LUT calibration. You can use any XYZ(RGB) profile there, conversion tables will be loaded as board's LUT. This is universal and much better than loading with 3rd party LUT load tools, including those provided with calibrators. So the graphics software just need to support basic sRGB, and no ICM is necessary (when OS "working" space is set to sRGB).
In Windows XP it was different - OS was providing only means of conversion (profile management) to ICM-aware programs, and no hardware calibration.

The monitor profile will not be sRGB so the sRGB profile in your Windows system should not be used.  You will need to use a calibrator such as X Rite or Datacolor Spyder to calibrate and profile your monitor.

No. Not exactly. Of course, color calibrator (colorimeter) is a preferred solution, but also an expensive one, and not always perfect (on some monitors). I would say, it is perfect only for monitors with "uploadable" 10bit LUT. BTW, some cheap LG monitors had calibrator attached 7 years ago, didn' see them for long...

The software I am talking about (seems you are unaware) uses "fishnet" pattern test for balancing RGB to (visually) optimal grey. It is done in the whole range of brightness by specific GAMMA-RAMP formula. Either 1.8-2.2 or sRGB, by your choice.
Now, consider the monitor hardware (the LCD preamplifier factory configuration) - it is usually limited around sRGB, or AdobeRGB gamut. Inside the gamut there are nonlinear distortions, which we correct in software (GPU-LUT). That depends on monitor setup, so I recommend switching on the "sRGB" option if it is available.
So when it is in sRGB limits, and the gamma distortion was corrected, we can speak about more or less sSRB profiled monitor.
That is not for HDR monitors, where limitations are moved out, and we do not know how much without a colorimetric profile. Well.. with such gamma-correction it is still better that without.
This does not work on some monitors with exotic subpixel configuration, can probably fail on OLEds, where subpixels are not even.

You cannot use a camera to calibrate and produce an ICC monitor profile - at least as far as I know

I am a scientist. At least I was before becoming a sensors engineer.
I am always asking, WHY can't we do it, and how can we overcome it?
Leaving it just because one have no idea, or someone said it is useless is not an option.

Now talking about approach and problems.
1.Initial approach. I think about Argyll manual for RGB printer.
2. I need to make a brightness independent profile. I guess, "absolute colorimetrics" is not acceptable. Then, what intention should I use?
Maybe just tweak the brightness span (from deeper than black - to - brighter than bright) in photoshop linearly. Then use relative colorimetric intent in Argyll.
3. Lighting. Flash? Daylight? Probably white LEDs from left and right (a pair, or four $5 keyholder lights?). Because the monitor is LED.
... Or maybe shooting in the dark under the light of the monitor itself?
4. harder part with the camera. I have a Rebel(100D) which does not provide RAW output... and I am lazy installing Magic Lantern (probably I should). Can we do it with JPEG from the camera?  What are the settings? Manual ISO. Manual white point. Fixed exposition. What else?
5. White point? Did not use it for long, but seems there was a manual whitepoint option ("point it at the ceiling" feature). Should I point it at the a)IT8 target white patch (probably no). b)ceiling, c)at the photo-paper surface, d)at the monitor screen (white image), e)at the light source? I guess it should be "d".

I have to try it the next week, when I find an evening or two for experiments. Before that it would be great hearing your suggestions.

BTW. I kind of "profiled" scanner without having real IT8 target. I used old iPhone's IPS screen, which is a high grade sRGB device (now they make wide gamut, like Samsung, but specifications are obscure). I uploaded there IT8's TIFF image, and put it on maximal brightness.
Scanning was hard, needed tweaking in Photoshop. The result was so-so... But much better then no profile.

[digitaldog]

It's pointless to use any ICC display profile that doesn't define the actual behavior of the display.
In ICC aware applications, by design, the display profile is divorced from the data you are editing. That's why we have synthetics RGB working space profiles (that are indeed based on an emissive display but not the one you're using). The RGB values in the working space are previewed using Display Using Monitor Compensation with the display profile, hence why that profile needs to reflect the actual conditions of the display. For the preview. So Tony is correct that The monitor profile will not be sRGB so the sRGB profile in your Windows system should not be used.

[Hale_JP]

It's pointless to use any ICC display profile that doesn't define the actual behavior of the display.

Oh my friend!

---> Do you read at all? <---

We find out the "bee-have-ee-or" of the monitor using the pattern-test! Thats what we do! Not complete,  of course, relatively to some color temperature/white point of the monitor.
But it is better than nothing, and not so far from colorimeter-assisted profiling(case-by-case). Believe me.

In ICC aware applications, by design, the display profile is divorced from the data you are editing.

Of course NOT! We edit in "working" space, which is sRGB(obsolete, but still useful for "EZ" home editing), FOGRA39, or other loaded.
But what we see is very strongly linked to the monitor profile. We either load the profile to Photoshop (GIMP). Or we convert it to hardware calibration, and configure the software output to some standard target space, like sRGB, which is set in Windows as "working" space.
Letting Photoshop manage the photo-image colors is better for color. But calibrating all the Windows RGB output is universal and makes sense when you don't have Hi-End hardware, which expands limits beyond sRGB.

[Jim Kasson]

Windows, starting from Vista, can use a monitor Profile as a source for graphics-board LUT-based calibration in working space.
I.e. you don't have to provide an ICC to photoshop, just work in sRGB(for instance), and add that ICC to the monitor section in Windows Color Management Engine. Don't forget to turn "calibrate monitor" checkbox "on", and push a "reload" button.

previously I was using RGB-balancing visual-pattern based calibration tools. But those are far from perfect and fail, when Windows 10(Intel GPU driver) starts tweaking gamma out of the blue. So with adjusted gamma the fishnet balance gets wrong, and colors are unpredictable.

Now I got Wolfs IT8.

So my idea is calibrating my Canon 100D camera under fluorescent lamp light (a bunch of lamps at all directions as improvised sophites). As an alternative, I think about white LED lamps, because those are closer to modern LCD backlight.

Then get a printer-like test pattern on screen, shoot it with CANON, and generate a monitor profile...

I just don't have an Idea how should I make it in Argyll, because brightness is an arbitrary value when making photos...

The whole point of calibrating a monitor is to use a measuring device that sees colors like humans -- at least, like 92% of the men and 99% of the women. Cameras don't. What's the point of calibrating a monitor so that it is good when using whatever the CFA spectral responses of the camera happen to be? In the end, you're going to look at the monitor, not the camera.

Jim

[digitaldog]

Oh my friend!

Jumping to conclusions. 

We find out the "bee-have-ee-or" of the monitor using the pattern-test! Thats what we do! Of course, relatively to some color temperature/white point of the monitor.
But it is better than nothing, and not so far from colorimeter-assisted profiling(case-by-case). Believe me.

No, I don't believe you.
We find the colorimetric behavior of the display by measuring them with an instrument called a Colorimeter or Spectrophotometer. Anything less isn't better and it's useless.
But I think you've come to the wrong forum for help.
You need to begin here and then maybe, maybe you'll find some answers here from those who understand about display calibration, profiling and color management.
https://web.archive.org/web/20070119043614/http://www.takegreatpictures.com/HOME/Columns/Digital_Photography/Details/Color_Management_and_Display.fci

[Hale_JP]

Please, avoid over-quoting. It is an indication of weak argumentation.

Cameras don't. What's the point of calibrating a monitor so that it is good when using whatever the CFA spectral responses of the camera happen to be? In the end, you're going to look at the monitor, not the camera.

Jim. One moment,
Do we use profiled scanner as a "poor man's colorimeter"?
YES!
"whatever the CFA spectral responses of the SCANNER happen to be?"
I don't know! At least we profile it with a target!
Why can't we do it for a camera, in some fixed conditions? I guess, we can! We should define the conditions and dry doing it.

At least, our final goal is not numeric measurement, but some visible representation close to life-colors.

The whole point of calibrating a monitor is to use a measuring device that sees colors like humans -- at least, like 92% of the men and 99% of the women.

Do you understand that human vision is NOT absolute?
So the above mention is pointless. We see relatively to some white point, which is usually the widest bright object in front of us.
- The monitor.
The visible gamut nonlinearly changes depending on this point, brightness and other conditions.
So, we calibrate the GRAY gradient - we approximately calibrate the whole space. It is not colorimetric "absolute", but very close to "perceptual" intent.

Cameras don't.

That depends on the cam, its preamp electronics, LUT, software corrections when saving JPEG. Many factors. In sensor tech we just use them as absolute device with predescribed transfer function - it is much easier and safe from errors. But those cams are different.

What's the point of calibrating a monitor so that it is good when using whatever the CFA spectral responses of the camera happen to be? In the end, you're going to look at the monitor, not the camera.

Oh, YES! How could you forget it!
ANd the LCD monitor is very nonlinear per-channel. The distortion should be corrected per every brightness gradation. That insures "correct" perceptual color representation. Or better say approximates, because the measure of the "grey" is your eye in certain conditions.

[Hale_JP]

No, I don't believe you.

That is the strongest argument of THEOLOGY.

We find the colorimetric behavior of the display by measuring them

That is perfectly correct, EXPENSIVE and... useless. because you calibrate in absolute colorimetrics. and human eye is relative. Relative to the "white" CCFL, or LCD, relative to paper, or the room lighting. Yes, you use fixed darkroom conditions.
For general home user it is pointless.
But general LCD monitor is even worse than that, so we need to fix the "grey" gradient anyway, even when no colorimeter is available.

/P.S. For those super-cool owners of RGB colorimeters... I use ATOF VIS-NIR-SWIR spectroscopic filters at work for perfect metrological color representation... 3 weak VIS sensors look not so cool to me. Still I don't see a reason for spending couple of K$ for home appliances; pro-photography is not my business.

[digitaldog]

That is perfectly correct, EXPENSIVE and... useless. because you calibrate in absolute colorimetrics. and human eye is relative. Relative to the "white" CCFL, or LCD, relative to paper, or the room lighting. Yes, you use fixed darkroom conditions.
For general home user it is pointless.
But general LCD monitor is even worse than that, so we need to fix the "grey" gradient anyway, even when no colorimeter is available.

You are in the wrong forum for general home use discussions.
You are in the wrong forum for discussing the facts behind color management.
You really need to move on sir, you're proving to three of us, as a newbie here, your goal is to argue and as such, this is a much better use of your time (watching this):



This back and forth is CWOBaT (colossal waste of bandwidth and time)

[digitaldog]

Windows, starting from Vista, can use a monitor Profile as a source for graphics-board LUT-based calibration in working space.

NEXT, learn what a working space really is from the folks who coined the term!:
https://www.adobe.com/digitalimag/pdfs/phscs2ip_colspace.pdf

One other important rule when you select your preferred RGB working space: Never select a display profile. This highly device-dependent color space defeats the purpose of using a well- behaved synthetic working space. While some synthetic RGB working spaces are based on the behavior of a display, it is important to recognize that a working space isn’t a monitor color space (or vice versa).

[Jim Kasson]

Please, avoid over-quoting. It is an indication of weak argumentation.Jim. One moment,
Do we use profiled scanner as a "poor man's colorimeter"?
YES!
"whatever the CFA spectral responses of the SCANNER happen to be?"
I don't know! At least we profile it with a target!
Why can't we do it for a camera, in some fixed conditions? I guess, we can! We should define the conditions and dry doing it.

At least, our final goal is not numeric measurement, but some visible representation close to life-colors.
Do you understand that human vision is NOT absolute?
So the above mention is pointless. We see relatively to some white point, which is usually the widest bright object in front of us.
- The monitor.
The visible gamut nonlinearly changes depending on this point, brightness and other conditions.
So, we calibrate the GRAY gradient - we approximately calibrate the whole space. It is not colorimetric "absolute", but very close to "perceptual" intent.

That depends on the cam, its preamp electronics, LUT, software corrections when saving JPEG. Many factors. In sensor tech we just use them as absolute device with predescribed transfer function - it is much easier and safe from errors. But those cams are different.
Oh, YES! How could you forget it!
ANd the LCD monitor is very nonlinear per-channel. The distortion should be corrected per every brightness gradation. That insures "correct" perceptual color representation. Or better say approximates, because the measure of the "grey" is your eye in certain conditions.

I don't know where to begin. Do you know the expression: "not even wrong?"

Try reading some of this series:

https://blog.kasson.com/the-last-word/the-color-reproduction-problem/

Jim

[smthopr]

Windows, starting from Vista, can use a monitor Profile as a source for graphics-board LUT-based calibration in working space.
I.e. you don't have to provide an ICC to photoshop, just work in sRGB(for instance), and add that ICC to the monitor section in Windows Color Management Engine. Don't forget to turn "calibrate monitor" checkbox "on", and push a "reload" button.

previously I was using RGB-balancing visual-pattern based calibration tools. But those are far from perfect and fail, when Windows 10(Intel GPU driver) starts tweaking gamma out of the blue. So with adjusted gamma the fishnet balance gets wrong, and colors are unpredictable.

Now I got Wolfs IT8.

So my idea is calibrating my Canon 100D camera under fluorescent lamp light (a bunch of lamps at all directions as improvised sophites). As an alternative, I think about white LED lamps, because those are closer to modern LCD backlight.

Then get a printer-like test pattern on screen, shoot it with CANON, and generate a monitor profile...

I just don't have an Idea how should I make it in Argyll, because brightness is an arbitrary value when making photos...

I very much admire your scientific adventures into computer/display color science and calibration!

But, you are entering the "Twilight Zone" and I suspect will spend weeks or months of your life before you finally give up in frustration.

As a scientist, you are aware that you will need a color/density measuring device.  I have never found any of the visual calibration aids to work at all with digital, solid state displays.  Maybe a bit with an old CRT though... but those days are long gone.

So, you're attempting to use a digital camera as a color measurement device for your display?  Have some fun with this, but you will find that it will never work.  The spectral sensitivity of the camera sensor does not match the RGB emissions from the display and you will not succeed.  I know you will try this anyways, so have fun!  And let us know if you ever have any success.

And if you are going to foolishly (I think!) try to "calibrate" your camera using an it-8 image, you definitely do not want to use a florescent lamp or LED lamp for this as they are not full spectrum sources.  For your science experiment here, use a 3200k halogen movie lamp, or maybe try a camera flash.  In other words, something closer to a "black body", full spectrum source.

In the end, you could get a job a Mc Donald's and earn enough money for an iOne Display Pro monitor calibration system after about two days of work.  But that's not a Science adventure!!!!

Lastly, I'm not sure your understanding of Windows color management is completely wrong, but make sure you are using a high quality display whose color space is limited to sRGB.  If you have a wide gamut display, this will never work without actually measuring and profiling the actual display to create your profile, and, in Windows, this will only work with color managed applications like Photoshop or Lightroom.

Good luck!!!!!

[digitaldog]

I don't know where to begin. Do you know the expression: "not even wrong?"

Try reading some of this series:

https://blog.kasson.com/the-last-word/the-color-reproduction-problem/

Jim

He's really suffering all kinds of basic color management misunderstandings as outlined here in another post:
https://forum.luminous-landscape.com/index.php?topic=131822.msg1126173#msg1126173


Hale_JP, are you perhaps also known as Frans?   
Gotta ask as your posting (asking questions and dismissing all the correct answers), that you just joined LuLa yesterday, makes me wonder.....

[Doug Gray]

.....

4. harder part with the camera. I have a Rebel(100D) which does not provide RAW output
....

The Rebel 100D does have RAW format. Check your manual.

[digitaldog]

The Rebel 100D does have RAW format. Check your manual.

He needs help so, specifically   

[Frans Waterlander]

Hale_JP, are you perhaps also known as Frans?

I find that highly offensive!!! 

[digitaldog]

I find that highly offensive!!! 

Suspicion confirmed. 
U2 will get along famously.

[Frans Waterlander]

U2 will get along famously.

Like I said before, highly offensive.

[digitaldog]

Like I said before, highly offensive.

Come on, Hale_JP's few posts here haven't been that offensive. Like someone else we know, he asks questions expecting a predetermined answer, and when he doesn't get them, he pushes back. Sounds very familiar but as yet, not to the degree of being that offensive.
Let's give him time, as we have with others with similar posting agendas.