4.2 Auto Brightness Bug

[retsaw]

That can't be the problem. It constantly changes even when I don't move it at all, or the lighting does not change.

The amount of light the sensor receives can change without you perceiving a change in the amount of light, just changing the angle you are holding the tablet at can change the amount of light the sensor receives. Also the human eye is very good at adapting to different light levels without you noticing.

 

[Rich215]

The amount of light the sensor receives can change without you perceiving a change in the amount of light, just changing the angle you are holding the tablet at can change the amount of light the sensor receives. Also the human eye is very good at adapting to different light levels without you noticing.

That all may be true and I do not doubt it.....but it does not address the problem that this auto brightness problem is real. retsaw....I am not sure if you used the N7 with the 4.1.1 and 4.1.2 JB versions? If you did....didn't you notice how the auto brightness function is in comparison to the latest 2 versions of JB on the N7? It's totally buggy now.

Prior to 4.2 update on the first 2 versions of Jelly Bean, auto brightness worked perfectly.....now after 2 updates.....it is not working correctly. I surely hope they can fix this.

 

[Rich215]

Before 4.2 people were complaining that the brightness often took too long to adjust down, now people are complaining that it adjusts too much. I suspect the issue is that the sensor isn't very accurate, and the previous behavior just hid that fact.

Sent from my Nexus 7 using Android Central Forums

Missed this post by you....... Actually I did not notice the auto brightness being to slow to change on the earlier updates....I thought it worked pretty good on my unit. I wonder if there was any hardware changes in this element from different production runs.

 

[mr_nobody]

Prior to 4.2 update on the first 2 versions of Jelly Bean, auto brightness worked perfectly.

In my experience, I have never found auto brightness to be anything other than annoying on any device I have used. I always immediately disable it. It must be _really_ bad now if the above is true.

 

[retsaw]

That all may be true and I do not doubt it.....but it does not address the problem that this auto brightness problem is real. retsaw....I am not sure if you used the N7 with the 4.1.1 and 4.1.2 JB versions? If you did....didn't you notice how the auto brightness function is in comparison to the latest 2 versions of JB on the N7? It's totally buggy now.

I've been using my Nexus 7 everyday since the end of July when my pre-ordered device was delivered. It may be that you are seeing different behavior than I am, but I prefer how the auto-brightness behaves since 4.2, before that I always had to turn the screen off and on again to get it to adjust the brightness down when I moved the tablet somewhere darker. I think the real issue is they can't program a single behaviour that everyone will be happy with given the limitation of the light sensor they are using.

 

[hpilot]

The amount of light the sensor receives can change without you perceiving a change in the amount of light, just changing the angle you are holding the tablet at can change the amount of light the sensor receives. Also the human eye is very good at adapting to different light levels without you noticing.

I guess I'm having a hard time getting my point across. When the N7 is on the table (not holding it), the light will go up, then back down, then up etc. constantly all within the span of 2 or 3 minutes. The ambient light has NOT changed, and the device has NOT moved. Before 4.2 it worked perfectly. It's as simple as that. Maybe yours works, mine doesn't.

 

[tybo85]

Mine isn't working properly either it adjusts every 5-10 seconds and it is doing a number on my battery, before the update i could go three to four days on a charge, now im lucky to get a day and my usage is the same....

sent from my RAZR MAXX

 

[Mushroomturtle]

Totally agree hpilot, I've tested my Nexus 7 in constant light conditions, the behaviour of the auto-brightness is most definitely broken on my device.

 

[sr2012]

4.2.1 seems okay for me so far...

 

[natehoy]

I guess I'm having a hard time getting my point across. When the N7 is on the table (not holding it), the light will go up, then back down, then up etc. constantly all within the span of 2 or 3 minutes. The ambient light has NOT changed, and the device has NOT moved. Before 4.2 it worked perfectly. It's as simple as that. Maybe yours works, mine doesn't.

I can confirm this. I'm using an app called "Screen Brightness"(aka. "Custom Auto Brightness" by Dmitry Matuzko) on both my Thunderbolt and my Nexus 7. It allows you to customize how bright the screen is at specific ambient brightnesses, which is really useful because I generally dislike the factory defaults for auto brightness. It also allows you to update the frequency at which samples are taken and adjustments are made.

Since 4.2, I've noticed that even with the app set properly I was getting an up-and-down brightness pretty frequently, much to my annoyance.

I started the app (which shows the current brightness reading) and sure enough, the brightness indicator was jumping over very large gaps very rapidly even with my N7 sitting perfectly still on a table. This is not at all like the behavior I saw on 4.1.2, where the jumps were a lot smaller.

So that tells me two things:

1. It's software and will eventually be fixed. The sensor was a little twitchy before 4.2 but has now gone buggy.

2. The only current way around it for me using Auto brightness was to set a brightness that's a little higher than I'd like in a darkened room and a little darker than I'd like it in a lighted area, and set that constant brightness up to about an indicated 200lux, then do a more normal heuristic curve from there on up. Others might choose to turn off Auto and either choose a "good enough" brightness or set up a quick way to change brightness levels like Curvefish's "Brighness Level" or a similar quick brightness switch.

"Auto" seems fundamentally broken in 4.2 and 4.2.1. Not a critical flaw, but an annoying one nonetheless, and hopefully one that gets fixed.

 

[natehoy]

Missed this post by you....... Actually I did not notice the auto brightness being to slow to change on the earlier updates....I thought it worked pretty good on my unit. I wonder if there was any hardware changes in this element from different production runs.

That's possible. For the record, then, I have a C60 (first production batch, screen lift at no extra charge!) 16GB unit.

Running either AndroSensor or Custom Auto Brightness confirms that the ambient light sensor is deeply bonked in the head below about 300lux indicated, leaping from very low lux readings to 200, then 300, then back to low, all in a period of a few seconds in completely constant ambient light that should be about 80-100 lux as indicated by my HTC Thunderbolt sitting right next to it.

The sensor has never been spot-on, and there's always been a little variance, but lately it's been like a Jack Russell Terrier on crystal meth.

 

[ProDigit]

Same issue here.
It's most likely a bug in the video drivers.
trying to get the darks as dark as possible, and the brights as bright as possible, the tablet is constantly fluctuating between light and dark.
And it's really annoying when browsing or reading web pages, when the screen becomes brighter, or darker, just because a piece of screen estate is covered with a dark banner of spam or ads;
Heck, it even auto-adjusts while I write this post, getting darker, because there's more dark text on the screen;

Super annoying!!!!!

 

[dicacho]

same here... when is this going to be corrected?