Video Calibration Discs Reliable?

Discussion in 'Home Theater / Audio and Video - Misc Topics' started by Grayson Dere, Feb 5, 2019.

  1. Grayson Dere

    Grayson Dere Moderator
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    Hi everyone!

    I've been using home theater calibration discs for many years to tune my display but recently I've been curious to learn what opinions you all have as to the actual accuracy one can expect when using a disc such as Spears and Munsil, THX, or DVE (Digital Video Essentials), etc... One day I'll probably jump for a CalMan/SpectraCal setup but for now it's out of my reach financially.

    One question I do have regarding using the video calibration discs is when I'm using the blue filtered viewer (THX optimizer disc). When I'm adjusting color and tint sometimes it's very difficult to discern by eye any change to the picture quality unless I do large jumps in the + or - direction. Is this the main drawback of using said discs? I bet a hardware calibrator would be able to see the slight nuances the eye has a tough time to detect. Am I even performing a proper calibration without calibration hardware?

    Thanks for all your advice!
     
  2. mechman

    mechman Senior Admin
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    I missed this post somehow. :hide:

    In my opinion. the discs are good for setting brightness and contrast and that's about it. The blue filters are a joke. And before the advent of HDR/Dolby Vision, setting brightness and contrast correctly was 80% of your calibration.
     
  3. Grayson Dere

    Grayson Dere Moderator
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    Thanks for your response, Mechman! I've always been skeptical about those blue filters.. : )

    If it's not too much to ask would you happen to know the reasoning behind the filters being inaccurate?
     
  4. thrillcat

    thrillcat Moderator
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    On set, we used to use these 9" Sony field production monitors (things have changed with HD and higher resolutions, but I'm in post production now). They needed a quick calibration each time you plugged them in, and they had a "blue only" switch that made adjustment easier. The filters included with various calibration discs never gave the same effect/ability, though I can't scientifically say why.
     
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  5. mechman

    mechman Senior Admin
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    Off the top of my head because I cannot find any of my notes pertaining to this from my ISF course, because they are old. Blue filters were developed for CRT displays and we've evolved a bit since then. Plus, back when there were only CRTs around, meters for calibration were probably fairly expensive. Plus, calibration is all about standards and it's doubtful that a cheap blue filter would meet the criteria for setting color and tint. While it might get you closer, it's probably just as easy to get there by eye.
     
    #5 mechman, Mar 13, 2019 at 9:57 AM
    Last edited: Mar 14, 2019 at 9:28 AM
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  6. Grayson Dere

    Grayson Dere Moderator
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    That raises an interesting thought...I'm sure or fairly sure that CRT tubes were standardized in both color spectrum and light output when manufactured for television displays. If that statement is true does that mean today's LCDs w/ LED backlight aren't as consistent in color temp when going from one brand/model to another so it's therefore very difficult to use the Blue Filter when calibrating the color?
     
  7. mechman

    mechman Senior Admin
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    That's a very good question!
     

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