XZ1 Compact: Auto backlight not smooth

[ciaranirl]

Once again, as posted over on the main XZ1 forum here, this happens on my XZ1 Compact as well.  Anyone else?  Could someone from Sony support comment on whether this issue is currently being investigated?

[Snapples]

I don't have any of that.

[Sevdar]

The same 

From dark to light conditions if fine

But from light to dark is terrible 

[romanempire]

It looks like there is a longer delay between brightness changes when decreasing than when increasing the brightness.

I wonder whether that is due to hardware limitation or due to fixed number of steps configured in firmware.

[romanempire]

I did some tests on my device and found the reason.

On Android framework/application level brightness can be within values of 1-100.

Now, Sony has an illumination-service running on the device, which logs the brightness levels (in RGBA :smileyconfused:), and it shows when brightness actually gets changed.

Sony Xperia XZ1 has proper brightness handling from 25 to 100, where increase by 1 point corresponds in level change (or I don't notice missing levels, because it is already very bright), however on values less than that the following happens:

API*100, perceived change, illumination-service value
01-06, level 1, ff020202
07-10, level 2, ff030303
11-13, level 3, ff040404
14-16, level 4, ff050505
17-18, level 5, ff060606
19, level 6, ff070707
20-21, level 7, ff080808
22, level 9, ff090909
23, level 10, ff0a0a0a
24-25, level 11, ff0b0b0b
100, too bright, ffffffff

So what happens is while the system correctly sends brightness updates below 20%, something on the lower level translates that to only 7 brightness levels, and that causes the issues you are experiencing.

 I then went through the whole range and found that there is a non-linear dependency at the first half of input brightness range.

I suggest contacting support and asking to spread the brightness levels evenly across the whole range of values.

[moonshower]

romanempire, just BRAVO!

[EminOd]

Good day. After the update, the adaptive brightness adjustment began to work much better, but nevertheless, at a low level of brightness, jerks are noticeable with a decrease in the brightness level. Dear developers, still make this adaptive brightness adjustment. Thank you so much

[romanempire]

Eh, US XZ1 Compact is still on three months old firmware, so I am eager to see the change. However, I've tested linear brightness and it does not make much difference. The only way I found to make the transition smooth with current setup is to decrease a delay between steps, which may be too quick in real world conditions.

The backlight gets very bright very quick, and it may require some controller changes to provide intermediate voltage values to make transition really smooth.

[GAZ082]

I also had this issue. Will see how it evolves with the latest update. But It's annoying.

[GAZ082]

Yep, it's still there. Annoying.