iMac to HDMI = dark TV image

Discussion in 'Apple TV and Home Theater' started by Albone, Feb 8, 2010.

  1. Albone macrumors regular

    Joined:
    Jul 22, 2003
    #1
    So, I finally got the right cables to connect my 20inch imac to my HDTV through HDMI. However, the TV image is ridiculously dark. For instance, watching Dr. Horrible, in his lab you can see objects in the background on his desk and shelves. Gone, on the TV.

    Messing with the brightness controls and options on the iMac or the TV doesn't help. Does anyone else have this problem and have a solution?

    Thanks!
     
  2. xfiring macrumors member

    Joined:
    Oct 10, 2009
    #2
    Try going into Display Preference on your iMAC and messing with the color profiles / gamma. Try Adobe RGB.
     
  3. roidy macrumors 6502a

    Joined:
    Dec 30, 2008
    Location:
    Nottingham, UK
    #3
    HDMI has a couple of different output levels depending on the device in question. Most PC/Macs output a RGB signal with a value of between 0 and 255 where as video devices such as Blu-ray/DVD players and set top boxes output a RGB signal with a value of between 16 and 235. Most HDTV's are setup to accept the latter signal type and so if you feed them a PC/Mac type signal the lumanance is clipped making the image brightness look wrong. Most modern HDTV's will allow you to change the HDMI signal level type from the settings menu to match the type of signal your feeding it. On my Samsung TV the setting is called HDMI Black Level, on the PS3 the setting is called RGB Full/Limited Range, have a look on your TV for a similar setting and try that.
     
  4. Kaidan macrumors member

    Kaidan

    Joined:
    Jan 6, 2009
    Location:
    London, UK
    #4
    No probs outputting from my mini through HDMI, all perfect.
     
  5. Albone thread starter macrumors regular

    Joined:
    Jul 22, 2003
    #5
    I guess I have an older model HDMI TV. I think we got it in 2004 and there's no settings for darkness or RGB. We can control the brightness and contrast, but it doesn't seem to work.

    I'm guessing if it does it like that with my imac, it would behave the same with Apple TV.
     
  6. xfiring macrumors member

    Joined:
    Oct 10, 2009
    #6
    No, the Apple TV would display fine. It is built for that unlike the iMac or Mini.

    You can also use component video out and get the same output resolution as HDMI port.
     
  7. roidy macrumors 6502a

    Joined:
    Dec 30, 2008
    Location:
    Nottingham, UK
    #7
    No, the ATV has a setting to change the HDMI RGB level on the unit itself to match your TV.
     
  8. TonyK macrumors 6502a

    TonyK

    Joined:
    May 24, 2009
    #8
    We connected our 2005 G5 Quad using a DVI to HDMI adapter and have no issues with picture quality for things like YouTube and other websites.
     

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