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Re: Monitor placement



Hi Frank,
   Here are some notes I took at an ITS meeting a few years back about
monitors. As far as Under Vs Normal or Over Scan - we set up our monitors in
underscan and save the files as such. Changing the scan size changes the
brightness on the picture. We have our operators use underscan as a general
work habbit and use normal or overscan only to show the client what it will
be at home (more or less) and let them know why it looks a bit dimmer.
   Rob Laug

Monitors Calibration, ITS Meeting at MTI, NYC
December 1990
*NTSC = Never Twice (the) Same Color.
*White in Monitors is 6500 degrees.
*Stage lighting is 3200Degrees.
*RGB is based on the ability to reproduce surface colors.
*Visable differences to the eye between monitors is 1%.
*Most monitors only hold calibration for 500 hours constantly on and siganl
always applied.  An accurate calibration can go 8-900 hours within 1%
accuracy.
*Delta gun and dot Configauation has better apparent resolution overall, in
line dots at diagonal resolution.
  Contrast above 35 ft Lamberts decreases life of tube exponentially (2years
at 40 ft lam.)
  Contrast UP = Resolution DOWN
Ask Resolution at what light output?
  Stability in monitors requires stability in room tempurature.
Color gun should be used with window.
  Analyzers can track the life of your tubes.
Color (IRT) Gun's bulb is a car bulb to handle shaking.
  It has a life span of 20 hoursbefore the color changes.
Also current must be right.
*Auto setup devices need to be calibrated to same dot configuration as the
monitors to be aligned.
*Monitors should not be used in a black enviroment.  Area around monitor must
be lit, preferably patterened or picture with gray scale.  Maximum level 10%
of monitor.
*Monitor must be at eyelevel.
*Backround should be 2-3 picture heights back from screen.
*Operator should be 4-6 pictureheights from monitor and within 15 degrees of
center (viewing area is 30 degrees total).
*Refering to the 3 black bars on the bottom of SMPTE Bars, 4% above, 4% below
7.5 IRE.
   Should be dark enough so that 2 bars just disappear and the brightest is
still visable.
*Blue is the most Compressed (10% for White) and most expanded and that is
why it is used for chroma gain and phase.
*Edit enviroment must be at 6500 degrees (room and monitors).
*B&W monitors around the main monitorshould be 2/3 the peak white of the
color monitor.
*Movie theateres are 5500 degrees gray scale.
*When a monitor is not being used send black or constant motion video signal.
 Some monitors (Tektronics especially) will destroy the high voltage circuits
with no signal applied.