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Dammit Cubs

macrumors 68020
Original poster
Jul 31, 2007
2,127
731
Is there a significant battery difference in using the automatic ambient light sensor on your rMBP vs just using the keys to manually adjust the backlight keyboard?

I'm curious if i should turn it off.

Thanks.
 
Is there a significant battery difference in using the automatic ambient light sensor on your rMBP vs just using the keys to manually adjust the backlight keyboard?

I'm curious if i should turn it off.
Keyboard backlighting is not a significant impact on battery life. Screen brightness has a much bigger impact.
 
When on battery I run the keys and display at 50%. Doing light activity, like browsing the web and working in ms office, I get 7.5+ hours.
 
He was talking about the ambient light sensor (aka the webcam), not the backlit keyboard.
No, it's not the webcam. It's the ambient light sensor that adjusts the keyboard backlighting.
Is there a significant battery difference in using the automatic ambient light sensor on your rMBP vs just using the keys to manually adjust the backlight keyboard?
When on battery I run the keys and display at 50%. Doing light activity, like browsing the web and working in ms office, I get 7.5+ hours.
You won't get much difference by running with the keyboard backlighting at 100% or at zero. The screen brightness is impacting battery life far more than the keyboard backlighting.
 
No, it's not the webcam. It's the ambient light sensor that adjusts the keyboard backlighting.


You won't get much difference by running with the keyboard backlighting at 100% or at zero. The screen brightness is impacting battery life far more than the keyboard backlighting.

Yes, but from what I understood of his question, he's asking about the impact on battery life of the automatic switching based on the ambient light sensor feature, not of the keyboard backlight itself.

The ambient light sensor is the little hole next to the webcam. I imagine turning off automatic brightness for both the keyboard and screen would make the sensor inactive, thus reducing energy consumption, but nowhere near significantly.

imac-2011-light-sensor.jpg

This pic is from an iMac but it should look similar.
 
Yes, but from what I understood of his question, he's asking about the impact on battery life of the automatic switching based on the ambient light sensor feature, not of the keyboard backlight itself.

The ambient light sensor is the little hole next to the webcam. I imagine turning off automatic brightness for both the keyboard and screen would make the sensor inactive, thus reducing energy consumption, but nowhere near significantly.

Image
This pic is from an iMac but it should look similar.

This sounds like the info the OP was looking for. You may actually use less energy with the sensor on. It serves a purpose and lowers brightness for both the screen and display when it sees fit. Of course, you can alter its thresholds by manually adjusting keyboard and screen brightness using the keyboard buttons. I would leave it on. The consumption is negligible when it comes to its own consumptions and the savings that result.
 
Yes, but from what I understood of his question, he's asking about the impact on battery life of the automatic switching based on the ambient light sensor feature, not of the keyboard backlight itself.
The sensor and the automatic switching would use even less battery than the backlight itself, which is negligible. Nothing related to keyboard backlighting will impact battery life significantly.
 
He was talking about the ambient light sensor (aka the webcam), not the backlit keyboard.

I don't think it has any considerable impact.

I made a mistake. I thought the ambient light sensor was designed to detect whether or not to turn on the back lit keyboard.
 
I made a mistake. I thought the ambient light sensor was designed to detect whether or not to turn on the back lit keyboard.
No, you didn't make a mistake. That's what the ambient light sensor does. It makes little to no impact on battery life whether the keyboard backlight is on or off, or whether it's setting is automatic or manual.
 
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