1. Join Now

    AVForums.com uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Calibration sticky?

Discussion in 'Home Cinema Buying & Building' started by Gary Lightfoot, Mar 24, 2004.

  1. Gary Lightfoot

    Gary Lightfoot
    Distinguished Member

    Joined:
    Apr 6, 2001
    Messages:
    12,302
    Products Owned:
    1
    Products Wanted:
    1
    Trophy Points:
    166
    Location:
    Surrey. UK.
    Ratings:
    +2,016
    I've always thought that people who have projectors should as a minimum, use something like Avia to set white and black levels. This ensures you aren't losing any shadow or bright details, and can help reduce mpg artefacts, especialy from the darker areas.

    Having recently taken an interest in calibration (as have others - you know who you are Buns), and the miriad of questions it's brought up (for me at least), I wondered if there was some kind soul out there who could make a calibration 'sticky' for the forum so that someone could learn the basics, and others with some calibration equipment, could learn something more advanced.

    Having recently chatted with the likes of Jeff Paynter, Paul Hayword, Gordon Frasier and others on the US forum, I realise this is no easy and simple task to put in a simple post, but maybe some basics combined with some web links would do the trick.

    Anybody else got any thoughts on this? :)

    Cheers,

    Gary.
     
  2. CrispyXUK

    CrispyXUK
    Active Member

    Joined:
    Feb 5, 2003
    Messages:
    3,714
    Products Owned:
    0
    Products Wanted:
    1
    Trophy Points:
    71
    Location:
    Land of the Living, Essex
    Ratings:
    +33
    well to start, is it true that you should leave the source (dvd, htpc etc.) untouched and only calibrate the display? I would be very interested in this as my PJ should turn up soon.

    To start though, most people have the THX optimiser which for most will be a good start it can be found on the T2: ultimate edition & Star Wars EP2
     
  3. Gary Lightfoot

    Gary Lightfoot
    Distinguished Member

    Joined:
    Apr 6, 2001
    Messages:
    12,302
    Products Owned:
    1
    Products Wanted:
    1
    Trophy Points:
    166
    Location:
    Surrey. UK.
    Ratings:
    +2,016
    Hi Crispy,

    Yes, I believe you're correct and that's how I've always tried to do mine anyway (HTPC gamma is another story...), but hopefully we'll get something a bit more definitive from those who know what they're doing. :)

    The THX optimiser is a start, but unfortunately you'll find that each optimiser is only optimised for the disk it's on - use another and your settings will be out. It may be ok to get you in the ballpark so to speak, but I wouldn't use it as a blanket calibration in the same way Avia or VE can be used for example.

    I have found that the THX drop shadow test for black level doesn't always have a shadow you can reveal. Some disks do, others don't, so that was one issue I had with them and why I use Avia instead.

    Gary.
     
  4. beecee

    beecee
    Well-known Member

    Joined:
    Dec 8, 2003
    Messages:
    2,038
    Products Owned:
    1
    Products Wanted:
    0
    Trophy Points:
    86
    Location:
    Kirkcaldy, Fife
    Ratings:
    +270
    i have tinkered with the thx optimiser in fight club but found that limiting. so after reading here i picked up Avia for my NTSC sources and then DVE for PAL as Avia dosn't do pal (as far as i know) but some help in calibration is always helpfull as i am a complete newbie to the pj scene.
     
  5. Gordon @ Convergent AV

    Gordon @ Convergent AV
    Distinguished Member AVForums Sponsor

    Joined:
    Jul 13, 2000
    Messages:
    13,981
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    166
    Location:
    Living in Surrey, covering UK!
    Ratings:
    +2,785
    No its not true you should do the display only.

    I will dip in and out of this with comments that can be added where appropriate.

    You need to calibrate the chain. There are actually standards for the electrical signals that come out of consumer goods. That's not to say that manufacturers stick to them, or that tolerances within a manufacturers range is such that all devices will be the same. If you want under 1% errors then buy a TAG or Linn etc.

    Many DVD players have their own settings for colour, contrast brightness and even gamma. SKY boxes even have contrast controls! I have come across one manufacturers product that crushes white detail on its default! So you need to make sure the sources are outputting the correct signal first, then you need to make sure any video processing is not cocking it all up before finally getting to the display itself.

    Here's another little one for you. Some DVD players alter the level they stick black out at dependant on whether there is macrovision on the disc. With one of these players using AVIA for brightness may result in incorrect settings when playing back copyprotected discs (ie most dvd's except Superbits it seems) Lumagen at least allow you to create service menu offsets to fix this "feature" when you partner their scalers with such DVD players.

    Cheers,

    Gordon
     
  6. Gary Lightfoot

    Gary Lightfoot
    Distinguished Member

    Joined:
    Apr 6, 2001
    Messages:
    12,302
    Products Owned:
    1
    Products Wanted:
    1
    Trophy Points:
    166
    Location:
    Surrey. UK.
    Ratings:
    +2,016
    Thanks Gordon,

    That's one myth already exploded. :)

    Gary.
     
  7. theritz

    theritz
    Active Member

    Joined:
    Aug 17, 2002
    Messages:
    2,451
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    51
    Location:
    Ireland
    Ratings:
    +27
    Gary - good idea..............

    Gordon,

    I understand that if a dvd player/ hcpc/ whatever is crushing whites or blacks in its signal then a display device can't "uncrush" them..... but how do you calibrate a dvd player in the first instance... how do you establish which device in the chain (the dvd player, processor or the projector) is the one causing the problem ?

    The display capacity (and tweakability) of the AE100 is very limited by comparison to pjs of the HT1000 class, but I fixed the settings on my hcpc by connecting it to a monitor set to 6500k, default brightness etc. before connecting it to the projector and then calibrating the projector using avia. While the AE100 suffers the normal "green mist" in very dark scenes associated with LCD, I am very happy with the skin tones and overall balance of the image on the whole.


    Sean.
     
  8. RTFM

    RTFM
    Active Member

    Joined:
    Mar 6, 2003
    Messages:
    1,014
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    38
    Location:
    Horsham, West Sussex
    Ratings:
    +17
    Good idea Gary.
    Won't be easy as there are so many ways of measuring contrast,
    brightness etc. ie. direct or reflected (screen characteristics come into play) But i'm sure with some input from the likes of Paul and Gordon it could be very worthwhile.
    Maybe we could even get some of our pals from AVS to contribute like we do on their forum.
     

Share This Page

Loading...