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E.2.3, Color metrics – NewTek TriCaster TC1 (2 RU) User Manual

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Let’s move on to a slightly more rigorous testing.

E.2.3

COLOR METRICS

At this point, we’ve assured ourselves that the signal from the camera is neither too bright nor too da

rk, that

its output falls within broadcast legal luminance limits, and that the black & white part of the signal does not
have an unwanted color cast.

We haven’t done anything yet, though, to assure our reds are red, not slightly brown, or that our blues a

re

not slightly green or magenta, etc. The

Vectorscope

can provide much more specific information about your

cameras color signal. Let’s see how it can assist you to ensure your colors are accurate.

U

SING

C

OLOR

B

ARS

You’ll no doubt have seen the familiar

color bars used as a standard reference for video signal calibration.

Two examples are shown here. Figure 381 is an example of the color bars used in NTSC countries, while
Figure 382 is a PAL example, common throughout European nations.

FIGURE 381 (NTSC)

FIGURE 382 (PAL)

You can use color bars in conjunction with

Waveform

and

Vectorscopes

to make sure the video supplied to is

consistent, accurate and broadcast legal. Most video cameras are capable of displaying color bars

check

your camera manual to see how to display these (given a choice, use 75% bars). Then look at the

Vectorscope

to see how it traces the individual colors comprising the image.

The

Vectorscope

graticule has six distinct rectangular

targets

, one each for Yellow, Red, Magenta, Cyan, Blue,

and Green. The targets are small rectangles with a cross-hair superimposed on them.

When a source is properly calibrated, the trace from the different colored segments of the color bars
displayed will fall right inside their individual targets (see Figure 383).