Can someone please explain 0 IRE and 7.5 IRE please?

Discussion in 'Archived Threads 2001-2004' started by jeff lam, Nov 18, 2002.

  1. jeff lam

    jeff lam Screenwriter

    Jun 4, 2001
    Likes Received:
    San Jose, CA
    Real Name:
    Jeff Lam
    I just got a new TV (sony 32HV600) and have an older sony basic player DVP560 and I am considering a new player. I was looking at the newer Panasonic ans sony players and noticed that sony has 7.5 IRE black levels and panasonic is adjustable 0 or 7.5. Now I'm not sure what this means. Is 0 blacker/darker than 7.5 and is this the propper setting? I do notice that on my set with my older sony which I assume is 7.5 IRE the blacks look dark grey and not completely black. This is after calibration with VE. I try to tone down the brightness to get the blacks darker but it doesn't work. When the screen goes dark during a blackout scene (like the beginning of LOTR's), I see the 16x9 frame due to the squeeze however the aspect ratio of the film is 2.35:1. I'm not sure if this bothers me yet but I was wondering if getting a player that has 0 IRE would get it blacker without darkening the overall picture.
  2. Scott Kimball

    Scott Kimball Screenwriter

    May 8, 2000
    Likes Received:
    Video Black starts at 0 IRE, while the American NTSC system starts "black" at 7.5 IRE.

    If you calibrate your set with enhanced black turned on, your DVD picture will have more range from black to white, giving a subtle enhancement to the picture. Unfortunately, when you switch back to an NTSC source (broadcast, VCR, etc), your blacks will be that much lighter if your set's black level is calibrated to 0.

    If your set has a memory for each input, this is not a problem - since your enhanced black will look fine on your DVDs, but when you switch to another source, your black level can be readjusted automatically to 7.5.

    This is somewhat of a hassle if you are going to use differing inputs on your TV (i.e. you don't have a dedicated HT setup for DVD only).

    I usually calibrate for 0 IRE and just up the brughtness control "by eye" when needed for other sources.

    Your mileage may vary.


Share This Page