From rjvbertin at gmail.com  Sun Jun  7 17:21:39 2026
From: rjvbertin at gmail.com (=?ISO-8859-1?Q?Ren=E9_J=2EV=2E?= Bertin)
Date: Sun, 07 Jun 2026 18:21:39 +0200
Subject: changing the screen brightness adjustment value
Message-ID: <6558915.UOh3bRxVsn@bmbl>

Hi,

Pressing the screen brightness keys on my laptop changes the brightness in steps of 10%. Or rather, via a fixed scale of brightness values that are 10% apart.

That's a little crude; 35% turns out to be the perfect setting for me. I can configure that value (with some trial and error) via the power  KCM but if I then use the brightness keys I can only achieve 30% or 40% brighness.

Is there any way to tweak this, or do I have to rebuild some component?

Thanks,
R.

From 1i5t5.duncan at cox.net  Tue Jun  9 05:32:20 2026
From: 1i5t5.duncan at cox.net (Duncan)
Date: Tue, 9 Jun 2026 04:32:20 -0000 (UTC)
Subject: changing the screen brightness adjustment value
References: <6558915.UOh3bRxVsn@bmbl>
Message-ID: <pan$1cb37$9d361f07$c1db4a22$e0d10113@cox.net>

René J.V. Bertin posted on Sun, 07 Jun 2026 18:21:39 +0200 as excerpted:

> Pressing the screen brightness keys on my laptop changes the brightness
> in steps of 10%. Or rather, via a fixed scale of brightness values that
> are 10% apart.
> 
> That's a little crude; 35% turns out to be the perfect setting for me. I
> can configure that value (with some trial and error) via the power  KCM
> but if I then use the brightness keys I can only achieve 30% or 40%
> brighness.
> 
> Is there any way to tweak this, or do I have to rebuild some component?

FWIW hoping someone else replies with a proper answer because I'm out on 
this one, which would likely be right up my alley and I'd have already 
dealt with it and have a patch if necessary (which being a gentooer is 
just a dropin to ensure it applies to future updates, once I have it), if 
I was on laptop.  But I'm desktop (and a decade old one at that...), and 
don't even have much of the infrastructure (beyond solid, which is a 
build-time dep for components I /do/ use) installed.

-- 
Duncan - List replies preferred.   No HTML msgs.
"Every nonfree program has a lord, a master --
and if you use the program, he is your master."  Richard Stallman


From rjvbertin at gmail.com  Tue Jun  9 14:00:26 2026
From: rjvbertin at gmail.com (=?ISO-8859-1?Q?Ren=E9_J=2EV=2E?= Bertin)
Date: Tue, 09 Jun 2026 15:00:26 +0200
Subject: changing the screen brightness adjustment value
In-Reply-To: <pan$1cb37$9d361f07$c1db4a22$e0d10113@cox.net>
References: <6558915.UOh3bRxVsn@bmbl>
 <pan$1cb37$9d361f07$c1db4a22$e0d10113@cox.net>
Message-ID: <118765879.R7yhSY1TfF@bmbl>

On Tuesday June 09 2026 04:32:20 Duncan wrote:

>FWIW hoping someone else replies with a proper answer because I'm out on 
>this one, which would likely be right up my alley and I'd have already 
>dealt with it and have a patch if necessary (which being a gentooer is 

Well, I dived a bit into some old code (as things like this are way easier to find before the "big bang" that occurred with KF5).
In KDE4, there were 2 overrides (implementations) of `PowerDevil::BackendInterface::brightnessKeyPressed(BrightnessKeyType, BrightnessControlType)` (for the HAL and the UPower backends). Both have a hardcoded 10% change stepsize.

I'm not sure if this will make it any easier to find the current code responsible for the feature, but I also have no reason to believe that will have been put under user control in later versions (the trend has more been in the opposite direction AFAICT).

From rjvbertin at gmail.com  Tue Jun  9 14:04:55 2026
From: rjvbertin at gmail.com (=?ISO-8859-1?Q?Ren=E9_J=2EV=2E?= Bertin)
Date: Tue, 09 Jun 2026 15:04:55 +0200
Subject: changing the screen brightness adjustment value
In-Reply-To: <pan$1cb37$9d361f07$c1db4a22$e0d10113@cox.net>
References: <6558915.UOh3bRxVsn@bmbl>
 <pan$1cb37$9d361f07$c1db4a22$e0d10113@cox.net>
Message-ID: <4061313.GJ48atsdke@bmbl>

On Tuesday June 09 2026 04:32:20 Duncan wrote:

>But I'm desktop (and a decade old one at that...), and 

Software control over the screen brightness on an external display is not impossible by definition; there's ddcutil (and its UI) and under X11 there is also some control via `xrandr --output $TARGET_SCREEN --brightness $factor` (but on my laptop that looks more like a contrast control at least for values > 1).

