Pyro Industries API-1394PCI Manual de usuario descargar pdf (Pagina 66)

■ THE CAPTURE TOOL: CAPTURE CONTROLS

Now let’s take a look at the Waveform monitor. As I mentioned before, the

Waveform monitor will address the brightness and blackness of the picture. We begin

by adjusting the black levels of the picture.

Have you ever watched television in the dark? You may have noticed that a

black picture isn’t really black; it’s sort of a muddied dark gray. In a standard video sig-

nal, it represents black. But the signal itself is running at about 7.5 percent brightness.

The first adjustment to make on your test signal is to adjust it so that the signal on the

Waveform is at 7.5. We do this by adjusting the contrast slider on the Input tool. This

control is a little weird. If you move the slider to the left, the black level goes up. Mov-

ing it to the right makes the signal go down. What’s up with that? The contrast is actu-

ally controlling the midtones of the picture, so when you adjust the levels downward,

the picture reveals less contrast, making it brighter.

Keep in mind that the first adjustment should be the contrast because the adjust-

ment of contrast affects the brightness and saturation of the picture as well. Adjusting

contrast first prevents you from chasing your tail and making brightness and saturation

adjustments all over again.

The second adjustment on the Waveform is brightness. With a test signal, the

brightness should not exceed 100 percent. However, if you have no test pattern and

some objects are as “hot” as 110 percent, it’s okay. Anything beyond 110 percent will

give you a blown-out or clipped look, in which images exceed normal brightness levels,

and the video has a sort of feedback effect. This might look stylish for some footage,

but if that’s not your intention here, keep it at 110 percent.

We’ll continue with the Vectorscope. When a test signal (such as SMPTE or EBU

color bars) is used, each color should show up correctly in the vector that corresponds

with it. If the vectors are off to the right or left of the boxes, you need to adjust the hue

setting on the Vectorscope. (Note: NTSC only: Hue adjustment is not available in PAL.)

If the signal doesn’t quite reach each vector in intensity (or if it is too intense and beyond

the vector), you need to adjust the saturation (SAT) of the picture. If your camera source

seems to be flat in color, there is a temptation to increase the intensity of saturation and

“Disneyize” the picture (the color becomes vivid, like a full-blown Disney animated

feature). But unlike film color, turning up the intensity of color using video can create a

lot of noise in the picture. You can use Avid’s color correction and color effect tools to

do this more efficiently than just blowing out your saturation when capturing.

Audio Settings

Before we look at the Audio tool, we need to establish some of the characteristics of

the audio coming into Free DV/Xpress Pro. To do this, look at the Project window,

which has several tabs. With a click, you can analyze the Bins, Settings, Effects, and

Info of your project. Click the Settings tab, and a list of adjustable settings appears in

4440c02rev.qxd 11/6/05 9:35 AM Page 45

1 2 ... 61 62 63 64 65 66 67 68 69 70 71 ... 370 371

Sin comentarios

Pyro Industries API-1394PCI Manual de usuario Pagina 66