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Videography Basics
shadow area, such as the recesses of a corner, reach pure black. This maximizes
the dynamic range of the image and also provides greater flexibility should you
wish to later post-process the scene in your editing software.
When setting up the dark zebra feature, the values you'll want to use will vary
depending on your camera and your vision for the look you are trying to achieve.
Audio Clipping
DV Rack provides visual Audio Clip Alerts when the audio signal exceeds the
range that your camcorder can digitize. Microphones are analog devices that turn
sound waves into electrical signals. These electrical signals are turned into digital
values by a chip in your camcorder. These digital values have a finite range,
(about -32,000 to 32,000).
Clipping occurs when parts of the signal go above the top of the digital range.
Since these values are above the range, there are no numbers large enough to rep-
resent them and they are lost forever. Back in the analog days you could get away
with some clipping but with today's digital signals, clipping is just about always a
really bad thing.
When clipping occurs, the most important thing is to detect it immediately since
there is nothing that can be done to fix the situation later. To stop clipping from
happening, you should use DV Rack to monitor the audio signal and adjust the
audio recording levels of your camera so that the loudest sound that will come
from the microphone will not be so loud that it clips. Other things that can be
done include:
• Reorienting the microphone, (pointing it further away from the loudest
sound)
• Repositioning the microphone farther from the sound source or
• Coaching your talent to reduce their dynamic range
Clipping does not always distort the sound to the human ear. In some cases, clip-
ping occurs at brief intervals, for example, when a person says the word pepper
and makes a “popping” sound when they pronounce the letter “P”. In fact, a sud-
den and brief audio “pop” may not clip at all but will still become an undesirable
artifact in your audio signal. This is why DV Rack also has a pop detector
designed to identify sudden surges in sound that don't clip but are likely to result
in unpleasant, and possibly, unusable audio.
An example of an audio signal with clipping
A properly recorded audio signal
