Your Daily Phil

DVE HD Basics Part II – Video Tests

Posted by lozenp on April 30, 2008

There’s a lot of content on this disc, there’s no doubt about that. I had to watch several of the sections a couple times to understand fully who to properly test and calibrate my picture. On top of just test patterns, there’s a couple hours of information on how HD signals are created, calibrated and adjusted at the source. I’m still working my way through that, but it’s certainly proving to be educational.

I made some discoveries about my TV during calibration. First, my TV doesn’t accuratly display below-black color, as systems standards say sets should. According to the disc, this is very common. Also, I found that my set will properly calibrate blue and red color, but can’t come close to getting green right. Using the provided color filters, I can see that the green coloring is far from what standards say it should be. Unfortuantely, my TV doesn’t have very good color-correction controls, especailly in the Component connection mode.

I also determined that my set is likely using the standard definition decoder for setting color, another very common issue in some HDTVs.

After about an hour of messing around, I made good progress in completing the video calibrations. Here’s how things have changed, my old settings are first:

  • Contrast – 89 to 92
  • Brightness – 54 to 58
  • Sharpness – 39 to 11
  • Color – 54 to 60

The biggest learning was the sharpness. This control is actually a holdover from the early days of color tv. In most cases, it seems this control doesn’t need to be active for HD signals. Sure enough, using the overscan test pattern, I was able to see I had mine set way too high.

The other thing that I was able to prove to myself is that my screen overscan is very poorly set. When looking at the overscan patter, I’m losing the bottom five percent of the picture, the left three percent, the top two percent and the right two percent. The biggest issue, however, is the amount of picture I’m losing off the bottom. I also determined that my picture is slightly rotated clockwise.

Those are all fixes that can’t be made in the general menus but only in the service menu of the TV. All TVs have service menus that are not accessible to the consumer because of the amount of damage a uneducated consumer could do to the set by getting into those menus. Hopefully I can call Best Buy and take advantage of my service plan to get some of these issues resolved, and maybe convince the tech to show me the service menus while he’s here.

Next up, the audio test patterns.


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