Wow, so happy someone else marked this, I thought I was hallucinating. It’s weird how it randomly drops down but is not indicated at all in the brightness.
And no, it’s not adaptive brightness or any other setting, it is a bug. I bet a lot of people don’t even notice, I only noticed when I was taking pictures outside and it kept jumping and I finally realized that it wasn’t just me, indeed it was the phone.
What exactly did you change with the brightness? I’ve noticed sometimes the screen suddenly clipping from max brightness to ~80%. The brightness slider will still be at 100% but the top 20% just doesn’t do anything. I’m not sure how the slider worked before the update but I certainly never saw this sudden darkening and I don’t remember the phone typically being this dim in sunlight. Not using automatic brightness or the “extra dim” setting.
This happened already before the recent update, please see above.
I have seen 1 report saying it even happens when adaptive brightness is turned off.
To all: please contactsupport to report this.
The slider doesn’t reflect the change for me, as affirmed by the other responders.
Yeah, I know that. That’s why I mentioned http://gitlab.fairphone.org; it’s their internal tracker and source repository. I only used the @ for future-proofing for if every they happen to create an account. It was some vague perfectionism.
Thanks though.
Outsourcing explains well how issues such as these manage to not be noticed. My FP4’s software is seriously buggy, in not solely this regard. It’s noticeable, even compared to my old Pixel 3’s.
As long as they fix it, eh.
Hi all.
Anyone find hard using the phone in sunny days? I cannot see the screen because the brightness is too low. Is there a way to fix it?
Best you can do is to make sure dark mode is not enabled. The screen indeed doesn’t perform well in sunlight.
Further: Have you turned off Adaptive brightness to ensure you can manually select the brightest setting?
Nope, that works fine.
Yes, at least switch Dark Mode off from sunrise to sunset. Anything else does not really make sense unless you have an AMOLED display anyway.
I think thats new and was not the case last summer… Its def too dark outside. Or lets say its more like this, because suddenly while writing its brighter while the slider was already at max.
I had the same issues last year, there were discussions about it on the forum as well. I don’t think the brightness is different. Also retest indoors, then the max brightness is more blinding. But in daylight that light is just not enough. And at night the lowest is too bright 
But at least the auto brightness is better now (for me).
Hi guys, thanks everyone for the reply.
I don’t have dark mode enabled and I turn the brightness manually at 100%.
It happens that as soon as I am in the sun the brightness is very high and I can see but after few minutes it drops for no reason. I hope this is something they can fix or I have to change phone cause in the sun is impossible to use it.
I can’t see that you have clarified
Are you actively using the screen i.e. touching it is have you stopped manual engagement and only viewing the screen?
As far as this does, I can’t imagine this happens to everyone, I’ve not heard my daughter complain of such, so maybe there is, in that sense’ no fix. It could be personal to your use or your phone.
As you confirm its the issue described in the other topic I linked I will close here and merge the topics.
@anon9989719 this happens regardless of if adaptive brightness is on or off and the slider stays at 100% with adaptive brightness on or off. I haven’t noticed that ever since yesterday, so sure it might be your daughter did not notice or is not affected.
Yes I think writing is quite active 
It is enough as long its properly working, however currently its not on some devices.
Brightness was insufficient in direct sunlight even with A11, at least on mine.
Now I think (but I am not sure) it has gotten even a little darker with A12.
No, extra-dim isn’t enabled (I’m a card-bearing member of the “it’s way too dark!” party), and as for adaptative brightness, if it doesn’t go to absolute maximum in direct sunlight (in southern France!) something is seriously broken!.. 
The correct summary would be, people complain about the max brightness in direct sunlight and some people also complain about the brightness itself being not stable.
I personally think it’s the same problem. Indoors the max brightness is bright. But in sunlight that max brightness is just bright enough to see some text on a white background. It’s not really sunny here yet. I don’t know how it is elsewhere, but if real sunny weather hits, then likely more people will complain again, like last year.
I can speak for me and for me it is and always was bright enough in sunlight last year! Now its not because brightness is dropping while the slider stays at 100%. So for me it has absolutely nothing to do with indoor or outdoor, there is a bug that some notice without sunlight (see first reports) and I notice so far only in sunlight. I work a lot outdoors, so for me I have hundrets of situations to compare and for me its normally bright enough if it would work properly which it is currently not. No one here reporting this is hallucinating, its quite obvious once it happens. Could have have imagined this before yesterday? No, as you have to experience to really understand.
I’ve seen it happen too, you’re not hallucinating indeed.
So I don’t think this summary is incorrect. Although I indeed think people may also complain about the max brightness and confuse the performance with indoor lighting. This was a topic last year as well. But let’s see and wait.
There is also another issue with the light/proximity sensor.
It doesn’t look like things are improving on that regard either. Maybe things will be better with the FP5.
Actually if you check the brightness sensor output, you’ll notice the sensor is rather limited, it cuts off way too soon, on both sides (dark and bright), thus erroneously reporting total darkness or full sunlight when it shouldn’t. It also has quite a steep response curve (resolution too low?).
If the proximity IR sensor is of similar built (or even the same part!) I am not surprised it reacts violently to passing tree shadows: Its output must be reporting a change from full light to total darkness with each shadow passing…