Monitor calibration with the nVidia driver

[absque fenestris]

I'm trying to set up something like color management in Linux Mint. After reading quite a few pages on the internet, I'm not much further than at the beginning: most instructions assume a hardware calibration with a color meter... I don't own it - and the question arises whether I need to have it.
From macOS I know that you can get some reasonable monitor settings in the system settings.
In Linux Mint the Nouveau driver was no revelation in this respect - but you can do something with the nVidia driver.
Brightness, Contrast and Gamma under Color Correction is good, but without a reference a blind flight.




1. A reference picture: here the ECI page helps. http://www.eci.org/en/downloads



Download the pc.zip (mac.sit is one of the few things you can't open with Linux...)
Choose the right size for the screen and load it as background image. It should be a 1:1 representation - if necessary cut to size with GIMP and export it as xxx.png.
Brightness and Contrast can now be adjusted, but the color cast - that is to despair.



2. This website helps: http://www.simpelfilter.de/farbmanageme ... punkt.html

(...there is a summary in English) Start with the black point setting and work through all the settings point by point.

Warning: It takes time and patience. Take a break after half an hour - go outside to adjust your eyes to normal daylight.
This said - do the calibration by daylight and not by candlelight.

Second warning: It looks not very spectacular. Maybe you'll be disappointed with the new settings. Well, this may be because the previous settings were far too aggressive, which means much too high contrast and wrong gamma values.

[carum carvi]

I'm trying to set up something like color management in Linux Mint. After reading quite a few pages on the internet, I'm not much further than at the beginning
From macOS I know that you can get some reasonable monitor settings in the system settings.
In Linux Mint the Nouveau driver was no revelation in this respect - but you can do something with the nVidia driver.
Brightness, Contrast and Gamma under Color Correction is good, but without a reference a blind flight.

I have been trying to play with the calibration in LinuxMint 19 as well. I noticed I could select different color profiles, but I was not able to change the settings of each color profile manually. I want a color profile with near to zero emission of blue light. It is possible on my standalone Eizo monitor, but not on my Lenovo T430 notebookscreen, as far as I know. Tips on how to change individual color profiles in LinuxMint 19 Cinnamon manually are very welcome!

Absque fenestris, I dont have an Nvidea driver though, but an Intel gpu. I am curious to know how far you got in trying to change settings with the Nouveau driver because many other LinuxMint user's are using that driver.

[absque fenestris]

Meanwhile, I've still consulted this website too:

http://www.lagom.nl/lcd-test/

Hi carum carvi
After experimenting a lot with the Nvidia settings, I managed to do the following on the very mediocre MacBook monitor:
1. black and white point are correct
2. gamma is 2.2.
especially the letter rendering has improved, i.e. there are no color fringes at the edges.
The monitor is extremely dependent on the viewing angle and slightly undercooled - i.e. bluish.
On OSX I would simply use 5500 Kelvin instead of 6200 in the settings here... or experiment with other Kelvin degrees.
The Nvidia settings unfortunately don't offer the possibility to change the color temperature or to adjust it steplessly.

What strikes me about many mediocre monitors is the bad representation of the printing colors: Cyan is mostly washed out or not at all a cyan, yellow seems grayed. This is also the case on this MacBook.

[carum carvi]

On OSX I would simply use 5500 Kelvin instead of 6200 in the settings here... or experiment with other Kelvin degrees.
The Nvidia settings unfortunately don't offer the possibility to change the color temperature or to adjust it steplessly.

Too bad that Nvidia cant change color temperature through HARDWARE settings, but Redshift (or the F.lux app for Apple) both can change the color temperature SOFTWARE settings.


Below are my personal color temperature SOFTWARE settings:
I use 2000 Kelvin with Redshift via the terminal command in LM19 Cinnamon:

Code: Select all

redshift -O 2000

In order for Redshift to be manually controlled in LinuxMint via terminal commands, one has to first shut down the graphical user interface program of Redshift, otherwise the terminal commands wont work.

I use 3500 Kelvin for a clearer picture sometimes... Might seem to be extremely low numbers, but I work in lowlight conditions, in the evening/night. White colors at 2000K have the same warm, yellow glow as flame lighting, which is comparable to candles. Very easy to the eyes in low light conditions. 2000K is (obviously) not suitable though for daylight conditions or for exact true life like color reproduction, which you seem to be looking for...

I have used that specific site (your link above) to do all sorts of testing, but in the end I only got frustrated by what kind of irregularities I started noticing. It is a good site though, with great tests that can be done.

Absque Fenestris, what do you know about screen flickering? I had especially bought a monitor that was flicker free, but now it seems only small notebook screens can be made to be genuinly (close to) flicker free, because in larger than 20 inch monitors the flicker free effect can only be achieved via (questionable) software tweaks, which dont seem to be as effective as the hardware flicker free settings in small notebook screens. Any thoughts on that...?

[absque fenestris]

Hi carum carvi

I noticed I could select different color profiles

...this is Mint Cinnamon 19.x? i miss color settings like this under MATE...


The good thing in OSX was the ability to calibrate AND adjust the color temperature in one window AND the ability to create different profiles for the same monitor...
Well, under macOS they make a lot of effort to make this system settings customer unfriendly.

Redshift scared me away once. Reminds me too firmly of a broken monitor... and nests itself too firmly in the system for my taste.
Actually, a simple switch for perhaps three color temperatures would be enough to complement the Nvidia card, e.g. 5000°K, 5600°K, 6200°K.
This manually - without any further jokes.

What do you mean with flickering?
On a static display, I can't see any flickering on any of my LCD monitors - not even on the very bad Acer Netbook monitor.
In contrast to earlier CRT monsters.
On the other hand, when scrolling or moving windows, the display on the MacBook is clearly better with Compiz. Acer Netbook is hopeless.
For graphics / CAD I have a 24" EIZO under OSX, macOS and Linux in VirtualBox. I don't have any problems with this monitor, however, this thing cost me enough...

Basically, you should always operate LCDs in their native resolution, which is clearly defined by the number of pixels. With external monitors you have to pay attention to good cables and of course to digital connections (VGA connections and cables convert the picture signal into analog and the monitor digitizes it again - that's pure nonsense).

Also basically I connect the whole computer equipment to socket strips with an integrated mains filter, e.g. an APC with five sockets.
They are not cheap - but what I read about cheap socket strips from the supermarket convinced me to invest a few Swiss francs more here.

To make this very clear: this discussion is about simple monitor calibration with Linux on-board tools. Mint MATE in my case...
A professional monitor calibration and profiling requires a colorimeter. Not quite cheap hardware.
If someone has good suggestions in this direction, I am very curious - especially if the price behaves halfway civilized.

[carum carvi]

i miss color settings like this under MATE...

LM19/LM19.1/LM19.2 Cinnamon all have some 15 different color profiles to choose from. This must be applicable in Mate as well. Mate is known for its good hardware support.

Redshift scared me away once. Reminds me too firmly of a broken monitor... and nests itself too firmly in the system for my taste.Actually, a simple switch for perhaps three color temperatures would be enough to complement the Nvidia card, e.g. 5000°K, 5600°K, 6200°K.
This manually - without any further jokes.

Code: Select all

redshift -O 5000

or

Code: Select all

redshift -O 6500

If Redshift is already installed, it is standard software in Cinnamon, all you have to do is enter those terminal commands and you will have your desired color temperature, without any further jokes
Redshift (or F.lux, which is the same basic software, with a different name), both those programs can achieve what you wish for, IF there isnt a better alternative. Why be scared of it? Nests too firmly in your system? It is just basic Linux tested software, like any other Linux software. It does the trick!

What do you mean with flickering? On a static display, I can't see any flickering on any of my LCD monitors

All monitors flicker, even the expensive EIZO ones, which I have myself as well. With reduced brightness the flickering becomes more apparently visible. Some monitors use software techniques to lessen the visible flickering. But if you dont have a problem with it, then everything is fine.

To make this very clear: this discussion is about simple monitor calibration with Linux on-board tools. Mint MATE in my case....

I found "dispcalGUI" software in the LinuxMint software manager and a good Linux website giving detailed information on how to use this Linux calibration software. See link below.

https://www.reallinuxuser.com/how-to-co ... -in-linux/

[Hoser Rob]

You can play with the settings but you can't properly calibrate it without a meter. It makes no sense. You need a reference.

[carum carvi]

I'm trying to set up something like color management in Linux Mint. After reading quite a few pages on the internet, I'm not much further than at the beginning: most instructions assume a hardware calibration with a color meter... I don't own it - and the question arises whether I need to have it.

Hoser Rob you are right, for a proper calibration you need a hardware colormeter. But provided absque fenestris is willing to buy that, this Linux calibration "dispcalGUI" software looks promising. I have just installed dispcalGUI software myself and it is very profesional looking software. Way above my understanding. I think Absque Fenestris is looking for something much simpler.

I dont care about calibration myself, but I do care about lowering blue color levels. I am thinking of using this "dispcalGUI" software in order to be able to change the RGB color levels manually, just to my likings. I have done that as well with the hardware settings on my EIZO monitor, but with my Lenovo T430 Thinkpad I cant find any hardware settings which I can change for RGB colors. Unfortunately this dispcalGUI software is so complicated for me personally I didnt succeed in changing the RGB colors, although I did experiment with different color profiles. The number of settings that can be tweaked in dispcalGUI software is stunning. Provided you know what it all means. And I dont....

[absque fenestris]

DisplayCal are nine single programs, four programs represent the Gnome Color Management and Argyll also runs somewhere - and finally all require a hardware calibration with a colorimeter - at least in Mint MATE.

I have tried to import "wrong" profiles: it's not possible.

Apple does a lot wrong, but regarding an uncomplicated monitor calibration and profiling, they had a bright moment.
Well, EyeOne, for example - that's the expensive professional department on the Mac - gets by with just one application.

But as I said, I'm not looking for an expensive professional solution, but a usable amateur setting.
To Redshift: Well I try it again, but know exactly that I will be annoyed about the time control...

[absque fenestris]

Redshift: downloaded Redshift with Synaptic (the one without GTK).
With redshift -O 5000 and redshift -O 6200 I created two starters - and Yes! that works.
If you still know if geoclue runs in the background or not, this is a very elegant solution.

Thanks carum carvi

[carum carvi]

Great that it works Absque Fenestris. The nice thing about the Redshift terminal commands is that they are indeed NOT limited to any timezone control. I hated that timezone control stuff in the GUI version of Redshift. But when I use the Redshift terminal command, what time of the day it is or in what timezone one lives, doesnt matter at all.

Enjoy your manually chosen color temperatures...

[absque fenestris]

For now, Redshift is only installed on the Acer netbook (Mint 18.3). With the setting on 5200°K the small monitor looks much better. I highly recommend it - the bad blue cast is gone. Unfortunately, the Intel graphics (as the Nouveau driver...) do not offer any further possibilities.

The MacBook still stays on Mint 17.3 - as it looks the upgrade will be Mint Cinnamon 19.1.

[carum carvi]

The MacBook still stays on Mint 17.3 - as it looks the upgrade will be Mint Cinnamon 19.1.

The new and great LM19.2 will be released in August. Perfect moment to upgrade to the newest and the best LinuxMint available! No severe bugs have been reported untill now. The beta release is already available and it can be upgraded to the stable version without any loss of data.

Great to hear that the blueish tint has disappeared thanks to Redshift's terminal commands!