PT2 dynamic backlight logic seems backwards
EDIT: Some of what I said below is not 100% accurate. See bottom of my message for some new edits.
I have the new PT2 and have really been enjoying it, for the most part. But one thing that irks me to no end is that the backlight is just too dim in dark rooms with dynamic backlight enabled.
I was playing around with the watch tonight to try to improve the situation and I’ve realized: I think the dynamic backlight logic is set up for an LCD screen, not an e-paper screen. On an LCD screen you need to dramatically ramp up the backlight level as the ambient light level increases, but an e-paper screen is just the opposite. In bright sunlight you don’t need the backlight at all, and it’s in a dark room that you need the most backlight help.
If you go to the backlight settings you can see the current backlight level as you change the various settings. Play around with it yourself, but what I’m seeing is if you have the ambient sensor enabled along with dynamic backlight, the higher the ambient light level the brighter the backlight (and correspondingly in dark environments the backlight level is very low). This makes it virtually impossible to read small text on the screen in the dark, even with the max brightness level set to blinding.
Obviously I can “fix” this by turning off the dynamic backlight, but I would prefer to keep it dynamic to optimize battery life since, if this were working properly, the backlight should get very little usage in day-to-day bright-light situations.
Are others seeing the same thing?
I’m on the latest firmware: v4.9.176
New findings as of 5/21/2026:
I played with this a bit more and found the current behavior is not exactly what I was describing. It's currently behaving a bit more like a bell curve, as ColorIsTheNewBlack described below, it just doesn't do a very good job of it, IMO. At very bright ambient light levels the backlight doesn't turn on (good), at low-medium light levels it's willing to bump up to max level, then at lower ambient levels it ramps it down significantly, often choosing 10% (which appears to be the minimum backlight level).
The bottom line is that there are too many cases where it's choosing 10% at low ambient light levels where that's just too dim for me, and there appears to be no way to influence this while retaining the dynamic backlight. Adjusting the max brightness level seems to have little-to-no effect on the shape of the brightness curve, especially at low ambient light levels. It seems only to make it willing to go higher when you're in that sweet middle-zone of ambient light where it calls on max brightness. Otherwise it's just as eager to go down to 10% in many other circumstances.
I recognize that it is a balancing act to determine what level of customization to offer users and I can imagine many options for resolving this, but ultimately I'd really love to be able to retain the dynamic backlight for battery reasons while being able to increase the brightness level selected at low ambient light levels.
I've taken out this GH issue: https://github.com/coredevices/PebbleOS/issues/1355