Auto-Brightness

[Zman-iPhone]

ok i cant tell if its working.

ive searched through the forums and nothing.

i have auto-brightness on. about 40%.

i will unlock it in my room which is dark. then ill turn my lamp on and it gets brighter. then i turn it off, and nothing... dont you think that it should go beck to what it was before?

thanks to all

zman

[adseguy]

The iPhone probably doesn't poll the sensor that often. Try moving around in applications. I've done it and it works.

[jordanabc2332]

Thanks for bringing this up Zman. I've noticed the exact same thing. I don't think it's a polling issue because I've waiting several minutes. It just doesn't auto adjust from light to dark...only dark to light.

Anyone else try this?

[Tinman]

I have heard that it only polls the light sensor when waking up from sleep. While I haven't verified this 100%, it does "seem" to be the case with my iPhone.


--
Mike

[leeladisky]

Originally Posted by Tinman

I have heard that it only polls the light sensor when waking up from sleep. While I haven't verified this 100%, it does "seem" to be the case with my iPhone.


--
Mike

Seems that it only polls after the screen is unlocked... try that.

L

[Tinman]

Originally Posted by leeladisky

Seems that it only polls after the screen is unlocked... try that.

L

That's what I meant by waking from sleep. I don't know how to to get to the unlock screen without the iPhone being asleep.

But yes, the actual polling does seem to take place after swiping-to-unlock is complete.


--
Mike

[jordanabc2332]

Check it out:

1. Lock Phone
2. Unlock phone in a dark area
3. Go to an area thats brighter
4. The phone will auto-adjust
5. Now, take the phone to a darker area...brightness will not auto-adjust

Now...

1. Lock Phone
2. Unlock phone in a bright area
3. Go to in area thats darker
4. The phone will NOT auto-adjust

Conclusion:

Every time the phone is unlocked it will adjust your brightness according to you surroundings. However, the phone will auto-adjust your brightness only if you go from an area thats dark to an area with more light. Auto-adjust does not work going from an area thats brighter to an area thats darker. This can only be adjusted by manually locking your phone and then unlocking it.

Hope that makes sense...

[Tinman]

Originally Posted by jordanabc2332

Check it out:

1. Lock Phone
2. Unlock phone in a dark area
3. Go to an area thats brighter
4. The phone will auto-adjust
5. Now, take the phone to a darker area...brightness will not auto-adjust

Now...

1. Lock Phone
2. Unlock phone in a bright area
3. Go to in area thats darker
4. The phone will NOT auto-adjust

Conclusion:

Every time the phone is unlocked it will adjust your brightness according to you surroundings. However, the phone will auto-adjust your brightness only if you go from an area thats dark to an area with more light. Auto-adjust does not work going from an area thats brighter to an area thats darker. This can only be adjusted by manually locking your phone and then unlocking it.

Hope that makes sense...

Yes, it makes sense.

I've tested my iPhone and that is exactly what I observed. I used my finger to cover the entire black plastic on the top of the iPhone (contains the light sensor). Sure enough, it auto-adjusted when going from dark to light.

My guess would be that Apple increases brightness when going from dark to light in order to deal with brightly lit areas (like outside, or outside in the car on a bright day). It needs extra backlighting in these situations. For sure, my iPhone is more readable in bright lighting than my Treo or any other color LCD device I have owned. And if it makes a mistake by turning up the brightness when it shouldn't there is no harm done other than a very slight loss of battery reserve.

When going from light to dark there is no problem seeing the screen (other than blindingly bright light! ). But if it made a mistake in that case, and lowered the brightness, it would make the display harder to read. This would get noticed.

So perhaps the compromise was to let it auto-adjust when going from dark to light, but not the other way around. Not too bad, as I just turn the iPhone off then on should I be in that situation.

Contrast all of this to the last auto-adjust backlight device I owned: an iPaq. That design was so poor I finally had to disable the feature. IIRC it adjusted so often, and so incorrectly, that it was more of a distraction than anything else.


--
Mike