Librem display osd feature request - brightness and RGB controls for hardware calibration

dear Purism,

i would like to - on behalf of everybody who owns or will own a librem device - ask you to give us the option to modify (from the OSD or through software) both brightness and individual RGB channels of the display monitor (for both the phone and laptops) in as fine increments as possible so we can easily and thoroughly hardware calibrate our monitors with external hardware calibrators.

there is no problem if the gamut of the screen doesn’t support 100% RGB it just needs to be able to juggle individual RGB channels and brightness. the rest are really not as important for hardware calibration but if more controls would be possible then that would be even better.

doing this will likely drop the power consumption of the display and will reduce eye strain together with all the other benefits that come with better color reproduction (both consumers and creators of content benefit from this)

it would also be an immense help if the said display had the features and capability to sense when the ambient light changes (both white point and level) and offer to change the profile based on different hardware measurements and calibration profiles setup beforehand by the user (which could cover darkroom, low-light, daylight, studio scenarios, etc)

i would also suggest not bothering with an illuminated keyboard. instead just make the whole backside of the panel display (for the laptops only) emit light based on the current display temperature selected by the user in the calibration profile or just have a single mode (between 2700k and 6500k selectable by the user) at very low lumen output so as to not draw to much power but still help with typing and reduce the contrast between the screen and ambient background.

i’m sure that everyone will benefit in the long run from such a feature and our eyes and final products will be thankfull.

i would also link to a few non-free hardware and software calibration solutions but i’m sure that’s not a problem for whoever is disatisfied with the performance of the above.

thanks for your attention and hard-work and please feel free to also contribute to this topic if you’d like.

wish you all the best !

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I’d actually kind of like this too. On Windows using the graphics configuration tool I like to adjust the individual colour brightness to match the lighting I’m in, something that colour temperature on Night Light doesn’t achieve very accurately. I don’t do it to have accurate colour, just to have a fairly accurate white point and to be easier on my eyes in my current environment.

Unless the display is OLED, if anything it would very slightly increase power usage.

Edit: Sorry, I was thinking of TN LCD… :man_facepalming:

You could somewhat do this with the camera I guess and adjust the display relative to the ambient colour. It would be a pretty neat feature!

the camera would pick the white POINT VERY inacurately and it wouldn’t sense the white LEVEL and it would be a half-baked non-profesional way to do things.

i’m talking about an embeded ambient sensor that would do both very easily and alert the user to change the profile manually or it could be configured to do it automatically if it finds a propper profile (configured beforehand by the user with the hardware calibrator for THAT specific condition).

i said that having the ambient sensor embeded in the laptop/phone chasis would be easier for a laptop/phone user if he has to stay mobile. he could do this with one of the colorimeters or spectrometers that have this ambient sensor embeded but that would mean an extra luggage and extra steps needed for just this “simple” task if the laptop/phone didn’t have this sensor embeded.

also OLED is very expensive for the desktop/laptop/mobile market. Asus has a PA22qc model with OLED for desktop/portable but it’s severly limited and costs 4k (aprox.). for the TV 4k/HDR market it’s only available with proprietary Ai chips which SPY on everything NETFLIX/browser related (which is why they are so “affordale” at “only” 1k $ and above. it’s very niche.

i also don’t see why it SHOULD draw MORE power if it’s accurately calibrated with a nice instrument. the complete RGB gamut is measured at 120 cd/m2 so anything higher than that would probably be not recommended for eye health. the nice thing about OLED and ultra high gamut IPS FALD displays is that bellow the 120 cd/m2 the profile LUT can be configured to offer very high sensitivity to blacks/mid-tones which is highly valuable for eye safety and power efficiency and generaly dark environments. look Ma’ , emacs running with a dark background on a 4k hdr oled screen ! oh wait did i say burn-in ?

currently the best options for desktop/pro use remain the IPS 500 + zones FALD displays which ARE expensive but they offer a very good compromise in comparison to OLED.

we won’t be seeing OLED screens anytime soon on a Purism product. i don’t even know why bother talking about it HERE …

Oh for sure, I didn’t mean it would be a perfect or professional solution. I was thinking more along the lines that if Purism doesn’t include the sensor you want, that someone could put something like that together with the existing hardware.

I just used OLED as an example because it is self emitting. What I meant was that because LCD doesn’t create its own light, rather the LCD blocks it to varying degrees, darkening one or several of the RGB channels to change the colour temperature would use more power not less. But then again, I guess it really depends on the default state of the LCD, like transparent or opaque. I was going to edit my answer but then didn’t bother. Either way, I would be very surprised if the power difference is at all significant.

for OLED TV or professional/external displays or ultra-high gamut panels for desktop there really is no point to be concerned about power draw. in that scenario the focus is creativity/less-eye-strain.

i only used the power draw for the mobile lcd use case which i have personally tested and it really makes a difference from a power draw standpoint. if i understood correctly the librem 5 will use an lcd pannel display and the laptops (v4s) are ips(?)…

the thing with ANY kind of integrated/external ambient-light-sensor is they aren’t usually accurate in regard to precise white level deduction. the white point is more or less acceptable for me. then again i know what (temperature) my LEDs used to illuminate my background are so it’s not usually neccesary to “measure” the white point if you know you’re bulb or led is 4000k (warm-daylight). this is for white-point ambient matching.

also with led ambient lighting for studio or any REAL color work you need to have a high CRI led (the most expensive) otherwise the colors will get messed up.

Gnome already has a “Night Light” (Settings - Devices - Displays - Night Light) which dims and shifts the color tehmerature of the screen at night. (you can’t adjust the exact temperatures though, on Ubuntu I use Redshift which is superior IMO as you can adjust both the day and night temperatures).

If you wanted dynamic temperature and brightness adjustmend not done by the camera, the hardware would have to integrate a light/color sensor. Which is definitely possible, they’re not that expensive. But a respin of the mainboard and top case would be required as it needs an additional hole where to sense fron (unless added externally, which would require manual work)

The other part of the “problem” is that Gnome lacks any integrated color/gamma adjustment tools outside of loading color profiles. Maybe some extensions exist?

Well not with the GUI out of the box anyway. You can change the Night Light temperature using gsettings or dconf-editor. There is also an extension to add a temperature slider to the top right pull down menu.

that is only a color filter meant as a last resort for people who don’t know or don’t care about a proper hardware calibration in regards to the ambient light. most people use their laptops at night with extremely poor lighting conditions or very dark room or no ambient lights at all. they just rely on the keyboard illumination to see what they are typing but that is extremly harmfull for the human eye which is very sensitive to contrast and adapts to compensate but the end result is fatigue and deterioration.

without direct display panel hardware controls to brightness and individual rgb color channels there is little use for a hardware calibrator as it requires setting targets for measurements and characterisation/profiling.

for instance my 4k samsung non qled/oled TV which i use strictly as a monitor (i don’t feed it any internet connections) can barely touch the rgb brightness targets i chose. that is because it is extremly poor quality. the reds and greens are bellow the target point and the blues are above @ 120cd/m2 brightness. but without a hardware calibrator (mine is a colorimetre which needs specific spectral corrections from spectrometers) i wouldn’t be able to figure this out. STANDARDS.