Monitors and picture reliability/ calibration

[MDM]

2 hours ago, dlmphotog said:

Nit pick for sure...

 

But words mean things. calibration/profiling

 

Monitor calibration (adjusting the internal LUT table or other internal adjustments) can only be done on high end monitors with their proprietary software.

 

Monitor profiling can be done with off the shelf software/hardware and makes a color corrected profile for a monitor that other color aware software can use to display corrected colors. Best practice is to profile the entire imaging process from capture to print so there are no surprises. I use a colorchecker passport to profile my camera sensor then I use NEC Spectraview to profile my monitor and you could profile your printer or get a color profile from a commercial printer.

This article on the difference between calibrating and profiling is probably the best explanation I have read. In my understanding, it is correct to say that you can only perform a fairly basic calibration of certain monitors including those on the iMacs. You can measure and adjust the luminance but I am not sure if you can adjust the colour through hardware calibration and profiling. What can be done probably depends on the iMac version  
 

That is why I mentioned the BenQ monitor which can be calibrated and profiled using a hardware calibrator such as the i1 discussed above. The BenQ range is a lot cheaper than the Eizo and NEC equivalents and has developed an excellent reputation among imaging professionals. There are some excellent reviews on that site I linked to above. 

 

 

Edited June 19, 2020 by MDM

[Harry Harrison]

Some Dell displays also support hardware calibration but only using their proprietary version of X-Rite Iprofiler called Dell Ultrasharp Color Calibration Solution (DUCCS) and only with the I1 Display Pro. They don't tend go out of their way to market them as such but this seems to be at least a partial list of the models that support this:

 

"DUCCS (Dell UltraSharp Color Calibration System) qualified monitors (UP3218K, UP3216Q, UP3214Q, UP3017, U3014, UP2718Q, UP2716D, UP2715K, U2713H, UP2516D, UP2414Q, U2413) have in their OSD (On Screen Display) -Color -Preset Modes, two color spaces called CAL1 and CAL2. You would use these two color spaces to "save" the X-Rite i1 Display Pro colorimeter hardware calibrations into the monitor."

 

That said, it may well be that their quality control and after sales service for such monitors would not be as good as BenQ, who do of course market their displays directly at photographers, and neither will be in quite the same stratosphere as Eizo, but then they won't be as expensive either.

[Harry Harrison]

3 hours ago, MDM said:

I have read. In my understanding, it is correct to say that you can only perform a fairly basic calibration of certain monitors including those on the iMacs. You can measure and adjust the luminance but I am not sure if you can adjust the colour through hardware calibration and profiling. What can be done probably depends on the iMac version

According to the article that I linked to above:

 

"It is also important to note that there is a distinction between what is commonly referred to as “hardware calibration”, where a wide-gamut monitor that has a built-in LUT (Look-Up Table) can be hardware-calibrated, and software calibration, where the video card changes color output to match the calibration profile. Since none of the Apple monitors come with LUT and cannot be hardware-calibrated, only software calibration method will work. And even for the latter, you will need to use a good quality colorimeter with the right kind of software to achieve desired results."

 

https://photographylife.com/how-to-calibrate-imac-and-imac-pro-displays

 

The author, Nasim Mansurov, goes into a lot of good detail about how to use DisplayCal/ArgyllCMS (actually in preference to IProfiler) to initially test  your own Imac (to the point of actually returning it if it's new) and then profiling it. It's the best guide to using DisplayCal that I've read. He actually uses the term 'calibrating' for what might properly be called profiling but distinguishes between hardware and software calibration. He does seem to show that you can significantly improve the colours on a Retina Imac.

 

DisplayCal actually has a first stage called 'calibrating' where you (if you can't use direct hardware calibration) use the monitor or operating system controls to get to the correct brightness, white balance and RGB levels before continuing to the 'profiling' stage.

 

I don't have a Retina display so I can't determine how successful this might be in practice. I now know that they are wide-gamut using the P3 colour space, what I'm not clear about is whether they also have an option to switch to the sRGB colour space which could be useful in certain situations I would have thought.

Edited June 19, 2020 by Harry Harrison

[M.Chapman]

3 hours ago, MDM said:

This article on the difference between calibrating and profiling is probably the best explanation I have read. In my understanding, it is correct to say that you can only perform a fairly basic calibration of certain monitors including those on the iMacs.

 

Excellent link thanks. This led me to these which give very good descriptions of exactly how profiles and colour spaces interact and the use of LAB to convert between them.

https://imagescience.com.au/fundamentals-of-digital/02-colour-management-theory

https://imagescience.com.au/fundamentals-of-digital/03-colour-management-practise-part-1

 

Mark

[M.Chapman]

4 minutes ago, Harry Harrison said:

According to the article that I linked to above:

 

"It is also important to note that there is a distinction between what is commonly referred to as “hardware calibration”, where a wide-gamut monitor that has a built-in LUT (Look-Up Table) can be hardware-calibrated, and software calibration, where the video card changes color output to match the calibration profile. Since none of the Apple monitors come with LUT and cannot be hardware-calibrated, only software calibration method will work. And even for the latter, you will need to use a good quality colorimeter with the right kind of software to achieve desired results."

 

https://photographylife.com/how-to-calibrate-imac-and-imac-pro-displays

 

The author, Nasim Mansurov, goes into a lot of good detail about how to use DisplayCal/ArgyllCMS (actually in preference to IProfiler) to initially test  your own Imac (to the point of actually returning it if it's new) and then profiling it. It's the best guide to using DisplayCal that I've read. He actually uses the term 'calibrating' for what might properly be called profiling but distinguishes between hardware and software calibration. He does seem to show that you can significantly improve the colours on a Retina Imac.

 

DisplayCal actually has a first stage called 'calibrating' where you (if you can't use direct hardware calibration) use the monitor or operating system controls to get to the correct brightness, white balance and RGB levels before continuing to the 'profiling' stage.

 

I don't have a Retina display so I can't determine how successful this might be in practice. I now know that they are wide-gamut using the P3 colour space, what I'm not clear about is whether they also have an option to switch to the sRGB colour space which could be useful in certain situations I would have thought.

 

I had a play with DisplayCAL and ArgyllCMS last night with my i1Pro and HP23xi display. Pretty impressive stuff. What it really bought home to me was the importance of specifying the right display technology before starting a calibration and profiling. The difference in measured white point between telling the DisplayCAL my display uses WhiteLED or RGB LED backlight is quite noticeable. I had to do some digging to find out which my display uses (Its spec just says LED backlight). DisplayCAL has excellent help on this.

 

The end result I got with DisplayCAL was very similar to the result from i1 Profiler software. But DisplayCAL seems to have more analysis options.

 

Mark

[Harry Harrison]

40 minutes ago, M.Chapman said:

The end result I got with DisplayCAL was very similar to the result from i1 Profiler software. But DisplayCAL seems to have more analysis options.

It's good to know that your results were similar but as you say DisplayCal does let you delve under the bonnet to a greater degree. There's also the matter of those 'correction' files which are particulalry intuitive.

[Harry Harrison]

42 minutes ago, M.Chapman said:

The difference in measured white point between telling the DisplayCAL my display uses WhiteLED or RGB LED backlight is quite noticeable.

I'm including myself in this observation by the way but it is so easy to just miss something and get a different or just plain wrong result, it's especially true with DisplayCal just because of all the options but it's probably true to a degree with any colour calibration/profiling software designed for professional use.

[MDM]

3 hours ago, Harry Harrison said:

According to the article that I linked to above:

 

"It is also important to note that there is a distinction between what is commonly referred to as “hardware calibration”, where a wide-gamut monitor that has a built-in LUT (Look-Up Table) can be hardware-calibrated, and software calibration, where the video card changes color output to match the calibration profile. Since none of the Apple monitors come with LUT and cannot be hardware-calibrated, only software calibration method will work. And even for the latter, you will need to use a good quality colorimeter with the right kind of software to achieve desired results."

 

https://photographylife.com/how-to-calibrate-imac-and-imac-pro-displays

 

The author, Nasim Mansurov, goes into a lot of good detail about how to use DisplayCal/ArgyllCMS (actually in preference to IProfiler) to initially test  your own Imac (to the point of actually returning it if it's new) and then profiling it. It's the best guide to using DisplayCal that I've read. He actually uses the term 'calibrating' for what might properly be called profiling but distinguishes between hardware and software calibration. He does seem to show that you can significantly improve the colours on a Retina Imac.

 

DisplayCal actually has a first stage called 'calibrating' where you (if you can't use direct hardware calibration) use the monitor or operating system controls to get to the correct brightness, white balance and RGB levels before continuing to the 'profiling' stage.

 

I don't have a Retina display so I can't determine how successful this might be in practice. I now know that they are wide-gamut using the P3 colour space, what I'm not clear about is whether they also have an option to switch to the sRGB colour space which could be useful in certain situations I would have thought.

Nasim Mansurov’s site is excellent- really good for Nikon camera reviews among other things. However, I would question his use of the term software calibration in the way that he uses it in that article. I normally think of software calibration as using the in-built software on a Mac where you squint at a weird pattern on the screen and try to match things up by eye - what I used to do before I bought my first colorimeter. The terminology is difficult enough without introducing an ambiguous term. The fact it uses a colorimeter seems to me to contradict the idea that it is software calibration anyway. I won’t be incorporating it into my vocabulary. 

[MDM]

3 hours ago, M.Chapman said:

 

Excellent link thanks. This led me to these which give very good descriptions of exactly how profiles and colour spaces interact and the use of LAB to convert between them.

https://imagescience.com.au/fundamentals-of-digital/02-colour-management-theory

https://imagescience.com.au/fundamentals-of-digital/03-colour-management-practise-part-1

 

Mark

I think he has a very good way of explaining complex ideas in simple terms. I discovered this site a little while back and would highly recommend it.