CRT video alignment calibration - No two DVD players alike

Discussion in 'Displays' started by Keith Paynter, May 15, 2005.

  1. Keith Paynter

    Keith Paynter Screenwriter

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    I had hoped to avoid this, but with the recent purchase of a Panasonic 30" 16:9 CT-30WX50, running my Pioneer DV-C505 player via composite inputs, and running the THX optimizer's 16x9 box and circle image (as found on The Incredibles and the Star Wars DVDs), I saw that my monitor needed position calibration. I had it done in-home a month ago by a certified service depot. Pretty easy, the tech just hit a combination of buttons on the remote and TV and was able to do it in a few minutes. Good thing this was still within a reasonable period for a free service call.

    Fast forward to today. I invested in a new DVD player (Sony DVP-NS975V) because I wanted separate 5.1 output, SACD support, and HDMI support for my new TV.

    Lo and behold, running the THX Optimizer on this player shows the image is out of alignment again! I was able to adjust the image myself thanks to a website that posted the same set of steps used by the tech who would have charged me about $50 to do it again.

    I haven't tried separate tests with more than 1 disc using the THX optimizer, but this makes me paranoid that any form of calibration is virtually worthless when DVD hardware is not referenced to similar specifications, and DVDs may not be standardized as well (this is not the same as the "safe area" of the CRT display hidden by the TV casing).

    Something else bothers me about the THX test - adjusting the contrast on the Greyscale THX image to their specification is a sure-fireway to get burn-from 2.35:1 titles or 1.33:1 progressive titles.
     
  2. ChrisWiggles

    ChrisWiggles Producer

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    Why do you say this...?
     
  3. Keith Paynter

    Keith Paynter Screenwriter

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    Chris, the Contrast adjustment for the THX page suggests that you see the front THX text but not its shadow, and that is supposed to be the optimum setting. This is potentially dangerous when you have a progessive player that blacks the left and right side on a 1.33:1 image (especially from an older B&W film) or a title that has a high proportion of brightly lit scenes.

    Checking the 16x9 box image on the THX Optimzer ("Incredibles" disc), I also found that the image itself is mastered left of center (I oversqueezed the horizontal width to check for s**ts & giggles), so it might be alright for that title, but what about a disc from another production house/studio? If I dont align to the "Incredibles" disc's specs the "newspaper headlines" are off center.
     
  4. ChrisWiggles

    ChrisWiggles Producer

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    But this is unrelated to burn-in, you are talking about setting the black level, not the white level. The white level is the issue on phosphor-based displays. You are confusing controls. Contrast/Picture is white level, brightness is black level. You observe the drop-shadow and black boxes to set black level (brightness). You use white patterns and boxes in test patterns to set white level (contrast). The two settings can interact.

    On a CRT display, you should use a low white level setting to lessen phosphor wear while still achieving a satisfying ft-L output for white. Again this has to do with white, not with black level.
     
  5. Keith Paynter

    Keith Paynter Screenwriter

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    Good point - hadn't considered that...
     

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