Strange technical iPad question.

Henning

Henning

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iHenning
I just read a tidbit, not sure as to the accuracy, stating that dimming the screen on iPads and other LCD screens uses more energy than full bright. The statement was that the way that screens dim is to increase the density of the LCD (which I agree increases the drain), rather than reducing the energy to the backlight.

Seemed like a somewhat incredible claim, but one that I could see potentially being true considering how power finicky some of the more efficient light sources are. If it is true and some knows it to be fact, I'd appreciate knowing because it will change the way I manage power.
 
SkyDog58 said:
The Apple website says:

Screen brightness can affect battery life. To maximize your battery life, use Auto Brightness or dim the screen.

https://support.apple.com/en-us/HT202613
Click to expand...

Right, but that doesn't answer the question. I understand that, which is why I do exactly that, and that is why I question the validity of the claim, it doesn't make sense when I compare it to how 'auto bright' manages the screen brightness. However, it doesn't actually answer the question directly.
 
I thought the question was whether dimming it uses more power or less power. Apple appears to say less power. As to the exact technical reasons, I do not know and I did not read your OP to be seeking that info but just an answer to the end result. Sorry that I was unable to help.
 
Doubt it. The backlight is obviously changing on my iDevices when I change the setting.
 
Dimming with LCDs is done by reducing the PWM duty cycle of the backlight, which is not the same thing as darkening a pixel by modulating the liquid crystal. Whatever source you read that from is flat wrong. Dimming does reduce power consumption of LCDs.
 
denverpilot said:
Doubt it. The backlight is obviously changing on my iDevices when I change the setting.
Click to expand...

That's the way it appears to me as well, sounds like the tidbit was a turd, it just came from what claims to be an authoratitive source which is why I questioned it to begin with.
 
From use during day at a brighter setting to use at night, feels like dimming does make a difference.
 
Easy to test. Set the thing full bright with a 100% battery and turn off the auto lock. Kill all apps.

Let it sit until shutdown.

Repeat at lowest brightness.

I'm certainly not going to waste my time doing it when it's obvious the backlight brightness is handled by the light itself and more electrons are inconvenienced by higher backlight settings than lower ones. :)
 
denverpilot said:
Easy to test. Set the thing full bright with a 100% battery and turn off the auto lock. Kill all apps.

Let it sit until shutdown.

Repeat at lowest brightness.

I'm certainly not going to waste my time doing it when it's obvious the backlight brightness is handled by the light itself and more electrons are inconvenienced by higher backlight settings than lower ones. :)
Click to expand...

Pretty much where I stand on it, the only thing that gave me pause is that some of the really efficient LEDs I have come across are very power specific. They are on with the right power, or they don't work properly.
 
I know of some older fluorescent backlit LCDs that would behave as described (couldn't modulate the brightness), but no modern LED backlit works like that anymore.
 
Don't forget that them Ynterwebs is full of truth. ;)

But I agree, modern back-lit displays work as logic dictates: more light = more power drain.
 
Unless Apple suddenly found a replacement for Samsung panels featuring some new technology, this is false. Making driving apps, the first thing we do to save the user's battery is dim the screen. One star ratings follow dead phones like night follows day.
 
BigBadLou said:
Don't forget that them Ynterwebs is full of truth. ;)

But I agree, modern back-lit displays work as logic dictates: more light = more power drain.
Click to expand...


Uh.....well, you can't post it on the interwebz if it's not true....duh!:rolleyes2:
 
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