[mythtv-users] Monitor adustment with SMPTE bars/ was: color adjustment
beww at beww.org
Wed Jan 27 04:28:07 UTC 2010
On Tuesday 26 January 2010 08:51:08 pm Bob wrote:
> I have my mythtv system connected to my TV via a standard "VGA"
> connector. The colors are off a bit, any suggestions on how to get them
> closer? I have a blue filter and a color bar pattern available to me.
I've never tried using one of those filters, but assuming it gives the same
effect as killing the red and green guns, this is what we used to do with
analog monitors. Probably doesn't apply to LCD or Plasma panels:
First question: what kind of bars so you have available? Real ones? you want
EIA bars at a minimum, and preferably split SMPTE bars. A PLUGE signal is a
plus. Bars produced by a camera, or off tape, or from most consumer devices are
Whether you want to set up with 75% bars or 100% bars is up to you, and
depends on what your bar generator will put out.
Turn off any dynamic processing the monitor might have.
Set the blacks:
If you have PLUGE: Set the black level so the transition from the highest part
of the PLUGE to the middle (reference blanking) is visible, but the transition
from the middle one to the lower one is not discernable.
Set chroma gain and phase:
Looking through the filter, you should see 4 vertical bars. Look at the
transition between the upper and lower bar (assuming you have split bars), and
adjust the color gain and phase ("Color" and "Tint") until the black is
uniform all up and down the black bars, the transitions should be invisible.
The controls will interact somewhat.
Setting the whites requires a photometer, but if all the above set up without
problems you are close enough, especially if you know that the monitor was
once set up correctly, with photometers etc.
Who said analog was easy ?
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