Is there an Open Hardware/F(L)OSS spectrophotometer for color management?

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Hi!
I’m thinking about taking my color management to a next level and calibrating/profiling my external monitor (LG W2442PA -SF) and laptop screen (Lenovo Thinkpad Yoga 12) (and maybe my aging printer (hp Photospamrt D6160), another office laser printer, and a projector, … and creating a color matrix for my camera).
My laptop has an IPS display, and as far as I understand to correctly calibrate that a colorimeter is not enough, but a spectrophotometer is needed.
A couple of years ago I was hoping for the ColorHug+, but the linked update sadly seems to have been the last one (and the website is offline as well). So I’m wondering if there is another alternative, any project worth to support? Or what would currently be the best spectrophotometer, working nicely under Linux/Ubuntu (and best fit to the FOSS values)?

In addition I’m wondering if I’m asking the right question: The darktable manual states:

Bear in mind that high-tier consumer-grade screens usually don’t need a user-made display profile unless you need to perform soft-proofing with professional expectations, since they are properly calibrated to sRGB in the factory.

I’m not sure if my before mentioned screens count as “high-tier consumer-grade”, but as I read that some screens even offer hardware calibration, maybe I should not spend the money on a spectrophotometer but on a new monitor instead?[1]

Any thoughts/experience? :slight_smile:

Thanks in advance!
Simon

[1] Sooner, or probably rather later I’ll probably will have to replace my laptop as well out of performance reasons. And as I would like it to stay portable (<13") I’m wondering about a model with Thunderbold 3 or 4 and an external GPU for performance. In that case I could watch out for the display characteristics of the new laptop as well (still not sure how to interpret “high-tier consumer-grade” or for what to watch out). But anyway, that’s probably a totally different discussion…

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I can’t really answer your question but you can get lots of great info here esp wrt monitor calibration and built in calibration

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Hello, as far as I know there is no open hardware spectrophotometer available. I use the iStudio from X-Rite and that works very well in combination with the Argyll Color Management System made by Graeme Gill.

According to me you can succesfully calibrate/profile your IPS monitor with a colorimeter. In the documentation of Argyll often the X-Rite Colormunki is used for this goal, or the Spyders from DataColor. If you want to make printer profiles for different papers as well, you’ll need a spectrophotometer in order to scan printed patches.

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Thanks for your reply.

Are you reffering to http://argyllcms.com/doc/WideGamutColmters.html? Because that was actually one resource that made me believe that a spectrophotometer is better suited to the task than a colorimeter. But maybe I understood it wrong?

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Hello, not in particular. In that article Graeme Gill talks about wide gamut screens, but I’m not sure if your laptop screen is wide gamut (it seems to be QHD, whatever that is, according to Lenovo). So I still think you can calibrate/profile that IPS screen with a colorimeter.

On the subject of monitors with built-in calibration, yes they exist, Eizo has some nice ones ($$), among other vendors. But if you want to calibrate those other machines you mention (a printer, external monitor, projector, camera), you might be better of with buying a spectrophotometer.

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Good question – I was trying to find an answer to as well. So wide gamut actually means >sRGB?! I wasn’t able to find a source on how much sRGB/AdobeRGB/… coverage the screen provides. :frowning: I got the info from Lenovo support, that the Yoga 12 has a display with “RGB LED (with extended color spectrum)”… Thus I was imagning, that it might be wide gamut…

Seems to be related to the screen resolution (but the Yoga 12 I own only has full HD, 1920x1080px.)

To try (not sure how to measure the success!?), I borrowed a Spyder 3 Express, just to stumble over some, older and newer colord/gnome-control-center bugs. Running Ubuntu 20.04 LTS I unfortunately didn’t manage to calibrate a screen with the Spyder 3 yet.

And then my external monitor started to show problems, not turning on after receiving power. So maybe I should start looking out for a new monitor before buying other hardware… :expressionless: Nevertheless would be good to get the Spyder 3 Express running.

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Try Argyll from the commandline. Anders Torgen wrote an excellent tutorial on this, might be working with your Spyder 3 as well.

That’s what I call a serious problem ! :wink:
Always check your cables to start with, try other ones if possible.

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So after installing the package colord-sensor-argyll I managed to successfully create a calibration for my laptop screen with medium quality using gnome color manager. :slight_smile: Retrying a calibration with high quality leads to the error message

(gnome-control-center:21093): color-cc-panel-WARNING **: 17:22:46.451: calibration failed with code 5: Gamma correction table was non-monotonic: 0,000000,0,000000,0,000000 0,048240,0,100000,0,045215 0,096480,0,100000,0,040430 0,144720,0,150000,0,135646 0,192959,0,200000,0,130861 0,241199,0,250000,0,226076 0,289439,0,300000,0,283791 0,312679,0,350000,0,316506 0,373419,0,400000,0,361721 0,434159,0,425000,0,400687 0,469899,0,475000,0,439652 0,518138,0,525000,0,484867 0,566378,0,568750,0,530082 0,608368,0,625000,0,578422 0,687858,0,696875,0,642388 0,723598,0,737500,0,678228 0,768713,0,793750,0,717193 0,826328,0,850000,0,768658 0,874568,0,900000,0,810748 0,910307,0,937500,0,846589 0,964797,1,000000,0,904304

(gnome-control-center:21093): color-cc-panel-WARNING **: 17:58:27.201: failed to start calibrate: failed to calibrate

No idea what the cause of the problem is, if it relates to the beforehand discussion of colorimeter vs. spectrphotometer for this display.
BTW retrying a calibration without restarting the gnome control center beforehand leads to the well known crash:

(gnome-control-center:21093): color-cc-panel-CRITICAL **: 18:10:19.661: cc_color_calibrate_setup: assertion 'calibrate->device_kind != CD_SENSOR_CAP_UNKNOWN' failed
Speicherzugriffsfehler (Speicherabzug geschrieben)

So I’ll retry with the other displays and then probably try your above mentioned suggestion running Argyll from the command line.

Edit: Did I mention, that the calibration screen with the colored swatches is always rendered on the laptop screen, also if I select the external monitor to be displayed? Makes it kind of impossible…

Yeah, I was a little sloppy there in describing my problem: The monitor only stays off maybe half of the time, in the other cases it turns on normally after receiving power. I already checked the cable without any success…

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So coming back from a couple of hours calibrating and profiling, @paulmatth thanks for the link, using Argyll from command line worked. Not sure though about the quality of the created icc-files though. Rerunning dispcal -H -t 6500 -b 100 dummy for the laptop screen (which has no knobs and buttons to fine tune), shows still after loading the icc-file a Delta E of 10…

To come a bit on topic again, using https://www.iccview.de it seems, that the laptop screen is definitely smaller than sRGB, while the LG nearly covers 100% – not too bad. :slight_smile: So a spectrophotometer might not be needed if I stick to calibrating the screens for now.
If waiting and hoping on its own will change the availability of an open hardware spectrophotometer is a different question…