31
32
20
However, if the loudness of main
sound and background noise are
not too far apart, the background
noise will be recorded at a
disturbingly high level. This can
be prevented to a degree by
turning the audio gain control of
the camera to
-
L" (low), as shown
in
Fig. 31 ,
and placing the
microphone closer to the to-be-
recorded sound source. The
lowered audio gain will reduce
the level of recorded background
noise, while the decreased
source-to-microphone distance
will raise the level of sound from
the main source. The result will be
a cleaner, clearer recording. The
"L"
(low) setting of the audio gain
control may be used to prevent
another undesirable effect caused
by background noise. When the
main sound source pauses
momentarily, as when a speaker
stops talking, the automatic audio
gain will amplify the only sound
available to it at the moment, the
background noise. The resulting
effect can be quite disturbing: in
one moment the speaker is heard
clearly, the next moment noises
can be heard, almost as loudly.
The remedy here is the same: turn
the audio gain control to "L" (low),
and place the mike closer to the
speaker.
There is another, and perhaps
best way to prevent background
noise from interfering with the
recorded sound: eliminate it. It is
often possible to silence the
offending background noise: an
air conditioner, TV, vacuum
cleaner in the next room, loud-
ticking clock, etc. may often be
turned off or stopped. Another
way of preventing background
noise is by changing location:
move camera and subject to a
quieter place.
Wind can also cause background
noise in outdoor movies. While
itself silent, wind blowing over
the mike often causes a whistling
sound in the recording. To mini-
mize wind noise, protect the
microphone with a shield formed
from approximately
1
/4 to
1
/2 inch
thick plastic foam sheet (available
in most 5 & 10 cent stores). Attach
the plastic foam to the micro-
phone with a rubber band, as
shown in
Fig. 32.
Wind screens
made for the purpose are also
available in many hi-fi stores.
To prevent camera noise from
being recorded, keep microphone
at a distance of
at least
3 feet
from the camera. If (particularly
in small rooms) the camera noise
persists, turn the audio gain
control to low ("L").
Handling the microphone can
also result in distracting back-
ground noise. Rather than hold-
ing it in the hand, it is better to
place the mike on its stand, or
tape it to some convenient object.
Professionals often hang up the
mike in front of and just above the
subject, outside of the picture
area. If there is an extra person to
hold it, the mike can be dangled
in place from the end of a fishing
pole.
