3rd Unibody MBP, and Screen Comparisons

Discussion in 'MacBook Pro' started by silentsage, Nov 22, 2008.

  1. silentsage macrumors member

    Joined:
    May 13, 2008
    #1
    Well, I'm on my third unibody MBP in three weeks. The first had a problem whereby it would occasionally develop random lines of corrupted pixels on the display. The second would randomly lock-up during use, and sometimes immediately after power-up. The local Apple store was great about the returns. I'm surprised at the problems, but not upset. I've bought a lot of hardware from Apple over the years, and on the whole the machines have been very reliable.

    There have been a lot of posts regarding screen quality. Just thought I'd post my observations of the three MBPs that I've had. The first had a 9C85 panel, and the second and third were 9C84s.

    First, the overall display quality of all three was outstanding. There was no perceptible difference between the first 9C85 and the first 9C84. The second 9C84 (the third MBP) is very slightly less bright than the first two. The contrast, sharpness, black level, saturation, and everything else was the same between all three.

    I suspect that the slight reduction in the brightness level of the second 9C84 might be related to the battery of the MBP or the internal power conditioning. I say this because the other perceptible difference in the second 9C84 is that the keyboard is also slightly less bright. I'm an electrical engineer, I've designed laptop hardware, and if I were trying the understand the difference in brightness, the first place I'd look on the second 9C84 is at the voltage supplied to the LEDs that drive the display and the keyboard.

    The other thing I noticed with all three is that the black level of the displays is somewhat sensitive to the angle of the display when you look at it. That is, if you sit directly in front of it, you can see the black level shift slightly as the display rotates forwards and backwards, or equivalently, as the view angle of the user moves from less than 90 degrees, to 90 degrees, to more than 90 degrees. With all three, the best black level was when view angle was 90 degrees (by view angle I mean the angle between the line of sight from your eyes to the surface of the screen). To see this, just move the screen back and forth.

    There have been posts that illustrate that the black level of the displays (9C84 and 9C85) are quite a bit different when the view angle is far from 90 degrees. I don't think this, of itself, is evidence of a problem. It is true that a property of a good display design is that it minimizes the black level shift when the view angle is not 90 degrees. To know if there is a real problem, you need to measure how much shift occurs as you move away from 90 degrees. It is possible that a display that has low black level shift when viewed from a 45 degree angle may have a worse absolute black level at 90 degrees - you need the entire set of measurements to make a comparison.

    In any event, just thought I share one set of observations that the 9C84 and 9C85 are very close in performance.
     
  2. Eddyisgreat macrumors 601

    Joined:
    Oct 24, 2007
    #2
    Just for reference, the difference between the old and new model Macbook Pro's can be referred to as "unibody" (for second gen) and "old" (for first gen).

    The Powerbook, First Design Macbook Pro and Unibody macbook pro are all aluminum.
    But you probably already know this :p.
     
  3. Sky Blue Guest

    Sky Blue

    Joined:
    Jan 8, 2005
    #3
    Wrong. Early 2008 and Late 2008.
     
  4. Eddyisgreat macrumors 601

    Joined:
    Oct 24, 2007
    #4
    Then how would one distinguish from a first gen (ati chipset) macbook pro body and the latest 2008 penryn (which was also used in the early 2k8's).

    I think it would be easier to designate chipset revisions in yearly intervals and body revisions in "unibody" or "non-unibody".
     
  5. silentsage thread starter macrumors member

    Joined:
    May 13, 2008
  6. integrat.ethis macrumors regular

    Joined:
    Oct 28, 2008
    #6
    Thanks, very informative (and comforting). Do you know which model had the greater black level shift?
     
  7. cherry su macrumors 65816

    cherry su

    Joined:
    Feb 28, 2008
    #7
    obviously the first gen (early 2006)'s body was missing a firewire 800 port, but this was rectified in the late 2006 models (also using ATi gfx) :)
     

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