Macbook dvi to hdmi

Discussion in 'MacBook' started by macattack08, Apr 20, 2008.

  1. macrumors newbie

    Joined:
    Apr 20, 2008
    #1
    Hi,
    I recently purchased a macbook and i bought the mini dvi to dvi dynex cable, along with a solid dvi-hdmi cable which i have connected to my 50' toshiba projection tv via hdmi. Whenever i play a video or anything, the image that appears on the tv is good quality, however, really dark and the black colors are more or less tinted/shaded green. Is there any way to adjust the contract or brightness for the TV, and/or the profile for my tv via the laptop?. I tried tweaking around a bit but all i can configure is the laptop lcd. BTW the tv is setup at 1080i - 1920x1080 interlaced. any suggestions would be greatly appreciated.
    thanks
     
  2. macrumors 6502a

    jonbravo77

    Joined:
    Feb 20, 2008
    Location:
    Phoenix, AZ
    #2
    Are you outputting the video on the extended display or are the displays mirrored? this is a big difference. The native resolution of the MacBook is only 1200X800 that is not HD quality, you will lose a lot in the picture going to the big screen if the big screen is set up for 1080i, the native resolution of the big screen is 1920X1080.

    The specs say that on extended display that the MB should output 1920x1200 if you run the video in the extended display part. Sorry to have to tell you this but I still don't think the picture quality is going to be that great either way. The video card of the MB is not an HD card and will not output HD quality, just the resolution.

    hope this helps

    Peace :cool:
     
  3. macrumors 6502

    Joined:
    Jan 18, 2008
    #3
    So you're saying that when setting the MB at its highest resolution settings, the results on the 50" 1080 psi HD TV will not be good quality?
     
  4. macrumors 6502a

    jonbravo77

    Joined:
    Feb 20, 2008
    Location:
    Phoenix, AZ
    #4
    It should look better but it still is not going to be HD quality.

    Peace:cool:
     
  5. macrumors member

    Joined:
    Jan 4, 2005
    Location:
    Berkeley, CA
    #5
    Could you say more about this - i.e. exactly why it's not going to be "HD Quality"?

    My understanding is that if the device generating the signal (in this case the MacBook) can generate a 1080i signal (1920x1080 interlaced, with high enough refresh rate), then that should be sufficient, and the picture displayed will indeed be HD quality, but dependent on the quality source stream (resolution and level of compression). But, I'm willing to learn.
     
  6. macrumors 6502a

    jonbravo77

    Joined:
    Feb 20, 2008
    Location:
    Phoenix, AZ
    #6
    I'm not sure how to explain this so I do apologize. There is a lot that goes on to make a true HD signal. I don't quite understand it myself. I do know that the Macbook (or any "off the shelf" laptop) does not have a video card that can truly output HD. It can however, output a resolution that can be technically HD resolution which is different than what true uncompressed HD is.

    I know this is all confusing and like I said I don't think I can explain it right. Try outputting the video you want to play on the secondary display at the 1920X1200 resolution. The green shaded black on your TV is a signal loss. The intel graphics cards that are in the MacBooks may just not have enough to output to that TV.

    I really wish I could explain this whole HD thing better and maybe someone else will see this and shed some light on it better than I can.

    Peace:cool:

    P.S. look at this forum and you will now see why this subject is so dang confusing. http://forums.afterdawn.com/thread_view.cfm/96495
     
  7. macrumors 65816

    jackiecanev2

    Joined:
    Jul 6, 2007
    #7
    Before you go worrying, just try calibrating your monitor.

    First thing first, either run your laptop in closed-lid mode connected to the tv (with power supply and external mouse/kb) or wake with remote with lid closed, then open lid to use the laptop kb/mouse, or run both the LCD and the TV. For these purposes, either of the closed-lid modes should be easiest.

    Under system prefs, theres a monitor option.

    *side note, if you're going to be switching a lot between externals, modes, etc, theres an option to display the monitor drop-down in the right menu bar. I find it useful.

    From the monitor settings panel, you can set your resolutions for the current monitor (assuming youre in closed mode, or for mirroring / extended displays if you've got the lappy lcd and the tv running). Set your res all the way up to 1920 x 1080, and you should be good to go there. You should have NO problems with a MB driving 1920 x 1080 to an external (which is all your tv really is, a giant digital external monitor).

    As far as the color issue, try calibrating. On the top of the prefs, you will see (display, [arrangement, if both monitors are on], color). Under color, hit calibrate. It will walk you through step by step instructions as to how to calibrate the color settings.

    GOOD LUCK. :)
     
  8. macrumors member

    Joined:
    Jan 4, 2005
    Location:
    Berkeley, CA
    #8
    macattack08 - I'm with jackiecanev2 on this. Given the type of problem you're encountering, a simple calibration problem seems most likely.

    And - jonbravo77 - unless you really understand an issue, or can refer to a credible source of information, it's probably better to not say anything. E.g. you say "I do know that the Macbook (or any "off the shelf" laptop) does not have a video card that can truly output HD". Firstly, "HD" by itself specifies an entire class of resolutions (720p up to 1080p, with a range of bit depths due to different ways of specifying color), with vastly differing processor requirements, which also depend on the compression type/bit rate of the data source.

    Secondly, many current laptops can display 1080p to an external monitor. My off-the-shelf MBP can easily do 1080p from a downloaded H.264 Quicktime movie trailer.

    Apple's recommendations for HD playback are here:
    http://www.apple.com/quicktime/guide/hd/recommendations.html
    So, a MacBook might be a little marginal for 1080p, depending on its processor speed, based on these recommendations. But, if it can't quite cut it, the problems will show up as stuttering or dropped frames, not smooth playback with color problems.
     
  9. macrumors demi-god

    xraydoc

    Joined:
    Oct 9, 2005
    Location:
    192.168.1.1
    #9
    My MacBook happily delivers 720P (actually 1280x768) to my Optoma projector without any difficulty.

    For the original poster, from the sound of it, its possible that there is a defect in the cabling somewhere. Can you independently test the mini-DVI to DVI adapter (Dynex is (one of) Best Buy's house brand, by the way, so who knows about the quality control). Can you independently test the DVI to HDMI cable on different machines/displays to verify its good as well?

    Since the laptop seems to be outputting a proper picture (resolution-wise) to your display, and if all cables prove good, it may be that the display needs some adjustment. Many displays can do independent adjustments per input, so calibrating one input for one source doesn't mess with settings for other sources on other inputs.

    But there's no such thing as "real HD." High-Def video includes, but is not limited to, 720P (720 pixels high), 1080i (540 pixels high, interlaced @ 60Hz) and 1080P (1080 pixels high). The width of the picture (resolution) is dependent on the aspect ratio, so at typical 16:9 it will be 1280 for 720P video and 1920 for 1080i/1080P video. 1336x768 is another resolution that I have seen not infrequently for 16:9 720P video (i.e., slightly scaled up). Many older and newer less-expensive 720P plasma displays use 1024x768 but with rectangular pixels and an internal scaler to produce a 16:9 image (rather than a 4:3 image). Photoshop I believe even has a special filter to handle rectangular pixels.

    However, be aware that not all HD televisions/displays are happy with a laptop/desktop driving the signal. For example, while my MacBook and wife's MacBook Pro have no problem displaying a picture on my Optoma 720P projector or Vizio 720P plasma, our Sony 55" rear-projection LCD (720P) doesn't display anything connected to the Mac. For what ever reason, my two Apple laptops wont sync properly with our Sony over HDMI.
     
  10. f1
    macrumors 6502

    Joined:
    Oct 11, 2007
    #10
    You need to callibrate your display. No need to mess with resolutions that has nothing to do with colors. And also when you hook up your macbook to an external in mirror mode your macbook defaults to the resolution of your external anyways NOT 1280x800
     

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