How do the Ambient Light Sensors Work in the MBP?

Discussion in 'MacBook Pro' started by carp3n0ct3m, Jul 25, 2007.

  1. carp3n0ct3m macrumors newbie

    Jan 3, 2007
    I've noticed that in the instruction manual, it points out that there are two Ambient Light Sensors, one in the left, and one in the right speaker. I was wondering under what conditions these are supposed to dim the screen. Is it required that both sensors experience this change in light condition for the screen to dim?

    The reason I ask is because I just bought a new 2.4ghz SR MBP and when my hand brushes over the right speaker/sensor, the screen dims. The screen does not dim at all when my hand passes over the left speaker/sensor.

    Thank you in advance,
  2. carp3n0ct3m thread starter macrumors newbie

    Jan 3, 2007
    Nevermind, I've researched it a little more and I think that my left sensor is broken, will have to go down to apple today or tomorrow.

    I just tried an app by the maker of the smackbook, but uses the light sensors rather than the motion sensor. Upon running the app it gives you light levels for each sensor. My right sensor is showing up as 835 while my left sensor is showing up as 75, and that's without me covering anything.

  3. roker macrumors regular


    Apr 14, 2007
    New Zealand
    Is this free software & where can it be downloaded from?? I would be interested to check mine. Cheers ;)
  4. clickclickw00t macrumors regular

    Jun 28, 2007
    dude, the right sensors dont really do anything. smackbook software specifically states that the right sensors are useless...
  5. irmatt macrumors newbie

    Jul 26, 2007
    Then why are they on the macbookpro if it wont do anything?
    It must do somthing.
  6. kolax macrumors G3

    Mar 20, 2007
    I'd think that one light sensor is for high level light and one is for detecting low level light to get the best and most accurate sensitivity.

    Just a guess - but I think the light sensors are useless to me anyway, I turn off the screen dimming feature, I prefer to control it myself.
  7. beginner0 macrumors member

    Jan 23, 2007
    For my MBP both have to be covered for it to dim.
  8. absoluttl macrumors newbie

    Jun 30, 2007
    Vancouver, BC
    Hi Justin,

    mine does the same thing but in the opposite way :) the left sensor seems to be the primary one. it was a cool feature for the first few days, i have then since turned off the auto adjustment (like many of us on the forum) and its really not that hard just adjust the brightness myself:)

    there's a software that can force the keyboard ambient light and manually adjust the brightness. Do a search then you will find it...its been mentioned many times on the forum <- i forgot the name on top of my head.

  9. WildCowboy Administrator/Editor


    Staff Member

    Jan 20, 2005

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