What is the method for setting up a studio video monitor using SMPTE color bars?

問題：

What is the method for setting up a studio video monitor using SMPTE color bars?

答案：

To set up a studio monitor, simply follow these step-by-step instructions:

1) Place the monitor in the environment in which it is intended to operate (the studio booth for example).

2) Dim the lights to levels they would be at during use of the monitor and try to block any light that might reflect off the surface of the monitor.

3) Turn on the monitor and allow several minutes for it to warm up. The display in a studio monitor changes dramatically depending on temperature so it is crucial that we let the monitor warm up to normal operation temperature.

4) Feed a SMPTE color bar pattern into the monitor from a camera or signal generator.

5) Turn the contrast knob (sometimes also called "picture") to its mid-point.

6) Turn the chroma knob (sometimes also called "color") all the way down until the color bars appear only as shades of grey.

7) You should see three small vertical rectangular regions in the bottom portion of the SMPTE bars underneath the red bar. These three columns are 3.5, 7.5 and 11.5 IRE from left to right respectively. Since 7.5 IRE is the darkest allowed color, there should be no perceptible difference between the 3.5 and 7.5 sections, but the 11.5 should appear to be slightly lighter. Adjust the brightness knob until the 3.5 and 7.5 bars just become indistinguishable from each other, the 11.5 bar should appear to be slightly lighter than them. Once this is done your monitor should have a properly configured black level.

8) Now to adjust the white level, turn the contrast knob to maximum. Now slowly turn down the contrast until you see the white bar just begin to change brightness, then stop. Now your white level should be properly set to 100 IRE.

9) Now that we have the black and white levels set, we need to adjust the color settings. Many monitors have a "blue only" switch, if your monitor has one of these, turn it on. If your monitor does not have a blue only switch then try holding a blue light gel in front of the monitor or your eye. You may need to use two gels to completely remove the red and green light, you can test if your gel is working by turning the chroma knob all the way up, if the red, green or yellow bars appear as anything but pure black then you need a stronger blue filter. You should now only see alternating grey and black bars.

10) Now that we are seeing only the blue channel one way or another, we need to adjust the chroma knob until the left most (grey) and rightmost (blue) bars are of equal brightness. The easiest way to do this is to adjust the knob until the top portions of these two bars match exactly the sub-bar right below them.

11) Once the leftmost and rightmost bars are of equal brightness, adjust the hue knob until the cyan and magenta bars are also of equal brightness. Again, the easiest way to do this is to adjust the hue until the cyan and magenta bars match their respective sub-bars.

12) Finally, turn off the blue only mode or remove your blue gel. The monitor should now be correctly configured.