Pyro Industries API-1394PCI Manual de usuario descargar pdf (Pagina 65)

CHAPTER 2: CAPTURING ■

The left side of the window is where you make adjustments. There are four

video sources to choose from. Note their order as they start with the lowest quality and

proceed to the best quality:

• Composite

• S-Video

• Component

•DV

We already discussed the merits of each of these, so let’s move on to the Wave-

form and Vectorscope tools. Now that you’ve set up the tools, what do they do?

Waveform tools are made to measure a lot of things, but here we are using them to

measure the brightness and darkness of the picture. The Vectorscope tool contains

many vectors, hence its name. Notice that each vector on the scope has some abbrevi-

ated notation. The abbreviations are as follows, starting at the top of the scope and

moving clockwise:

RRed

MG Magenta

BBlue

CY Cyan

G Green

YL Yellow

Did you notice any pattern to the order of these colors? If you’ve studied a color

wheel, you know that each color represented on the scope is 180 degrees opposite its

complementary color. The six colors consist of the three “primary” on-screen colors

(RGB: red, blue, and green) and their complements (cyan, yellow, and magenta).

The purpose of the Vectorscope is to make sure that these colors, when repro-

duced from a tape source, appear correctly in each corresponding vector box. The

problem is that there are very few pictures with full representation of each color. We

do have one such source, however: SMPTE color bars (NTSC) or EBU color bars

(PAL). Color bars are a test signal for measuring color (chrominance) and brightness

(luminance) as well as black levels in a picture.

Using Waveform and Vectorscope Monitors

Every recorded tape should begin with color bars. Okay, I didn’t just graduate from

tech school here; lots of field tapes are recorded without color bars. That still doesn’t

make it right! But if you have color bars on your tape, this is a good way of setting up

the tape so that levels can be properly set when digitizing. If there are no test signals on

your tapes, you can still set up the picture in pretty good fashion without them.

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Pyro Industries API-1394PCI Manual de usuario Pagina 65