lux 5000 is not an acceptable value. Valid values are 1 - 3000. A "good' value is 2500-3000.
If this does not work, please check your light sensor with other application (Elixir 2).
I'm already running this version on my phone. I just had second thoughts to release it or not.
According to elixier, the sensors max lux is 10240.
I guess the current brightness = (current lux)*(max brightness)/(max lux)
For max values, This means i get max brightness when the lux hits 3000.
It was very cloudy today, and the sensor reported ~3000-3500 lux
The screen went max bright, even though 255 brightness is too much for that amount of light.
I guess thats what the max brightness is for, but if i cap it at lower value, it wont be suitable for brighter environments, sunny day for example.