5 Replies Latest reply: Sep 13, 2012 9:35 AM by steve359
ingeniousfb Level 1 (0 points)

I bought a LG M2452D-PU monitor and am hooking it up to my late 2008 Al. Macbook using a HDMI cable and mini-displayport adapter. It won't display in the advertised 1920 x 1080 resolution. Why not?

MacBook, Mac OS X (10.6.8)
  • steve359 Level 6 (12,330 points)

    System Preferecnes > Displays:


    Screen shot 2012-09-12 at 11.53.34 PM.png


    When in "Mirror" mode, the resolution used on BOTH displays will be the lessre of the two maximum resolutions.  If Mirror is unchecked (thus "Extended"), both display can act independently.

  • ingeniousfb Level 1 (0 points)

    I've messed around with it a bit more now and I think I can explain the issue in more detail. (I am using the monitor as a second display, aka, not mirroring) In the display settings for the second monitor there is a list of resolutions. The highest specific resolution I can choose is 16xx by 10xx and then I have to check the overscan box to make it fill the screen. This distorts the image more then I'd like. The best image I've gotten so far is using the 1080p resolution and overscaning it. This should be 1920 x 1080 but when I use an image of that resolution as a desktop background it blows it up too big cutting off the edges. When I don't overscan, the image and the usable screen is smaller then the actual screen.


    Does this mean the LG M2452 doesn't have 1:1 pixel mapping for 1920 x 1080?


    Also, thanks for your reply, Steve.

  • steve359 Level 6 (12,330 points)

    Beyond my knowledge, sadly.


    The HD external monitor I use is truly a monitor with some TV-style inputs instead of being a TV that I am trying to use as a monitor and I have no issues.  That is not criticism, just statement of why I have not needed to deal with "overscan" and "pixel mapping".


    I hope someone who has followed your path will chime in.

  • ingeniousfb Level 1 (0 points)

    Yes, this LG is supposed to be that way too. I may have to return it and swap it with something different. Rather annoying. It was in Newegg's monitor section and had good reviews. I would think it was a good monitor for the price if it wasn't for this issue. I had no idea about pixel mapping until this issue came up either and I started researching it. It seems to be a fairly common problem but it's never in the specs of a monitor so I don't really know how to pick one that will work besides word of mouth.

  • steve359 Level 6 (12,330 points)

    I would tell you my model number, but I have had mine for at least 2 years so would be worthless to you.