ambient light sensor?

I saw this listed as a feature of the new iphone. Did the old iphone have this?

Yes it's what adjusts the brightness of the screen.

It's also what turns the screen off when you put it next to your face, preventing unwanted screen taps.

Kash said:

It's also what turns the screen off when you put it next to your face, preventing unwanted screen taps.

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Is it really the light sensor that does that or another proximity sensor.

If it was the light sensor, what would happen if you were using the phone in a really dark place.

EDIT: Just looked it up and it seams that the iPhone (I believe this goes for the original and 3G) has two sensors: a light sensor, and a proximity sensor...:

"Hidden behind the dark glass above the earpiece of your iPhone are the other two sensors, the proximity sensor and the ambient light sensor. The proximity sensor deactivates the touch sensitivity and illumination of the iPhone’s screen when the phone is placed against your head, but only during a call. The ambient light sensor detects lighting conditions when your iPhone is unlocked, dimming the screen in dark places and brightening the screen in sunlight to make the display easier to see."

-- http://www.theiphoneblog.com/2008/05/07/tip-o-the-week-outsmart-your-sensor/

i've never understood this....why do you want the screen dimmed in low light conditions? does that mean if it's pitch black where you are your iPhone wont have any background light at all ? And personally, whenever im in a really bright environment i turn down the brightness of my screen, not turn it up.

lukenn77 said:

i've never understood this....why do you want the screen dimmed in low light conditions? does that mean if it's pitch black where you are your iPhone wont have any background light at all ? And personally, whenever im in a really bright environment i turn down the brightness of my screen, not turn it up.

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I believe the one in the iphone senses the inferred light from your ear and dims it form that, I was using my friends iphone last night, in the dark, and the screen was bright.

lukenn77 said:

i've never understood this....why do you want the screen dimmed in low light conditions? does that mean if it's pitch black where you are your iPhone wont have any background light at all ? And personally, whenever im in a really bright environment i turn down the brightness of my screen, not turn it up.

Click to expand...

So you don't strain your eyes and it saves battery life. Watch a bright TV in a pitch black room and you'll know what I'm talking about. You don't need a lot of backlight to see in darkness anyway. And why would you turn the brightness DOWN in really bright places? Have you ever tried to use a laptop with the sun shining directly on the screen? It's terrible unless you have a bright backlight.