Every
camera shares certain essential elements: an optical system, one or more
picture pickup devices, preamplifiers, scanning circuits, blanking and synchronizing
circuits, video processing circuits, and control circuits. Color cameras also
include some kind of color-encoding circuit.
Recognize
the types of microphones used in television productions. Sound
plays a vital role
in the television communication
process. Most human
intelligence is transmitted through sound;
therefore, good quality sound is an important part of television.
However, good quality sound is rather difficult to achieve at times because
sound sources may be in motion, talent may speak to the camera and not
into the microphone and microphones
must sometimes be hidden from the
view of the camera. To help solve these audio
problems, we should have a basic understanding of television microphones.
Microphones
are usually classified according to the way
they pick up sound, also known as their polar pattern. Sound in physical terms
is the vibration of air particles or small fluctuations of air
pressure that spread like waves from a
source of sound. Human ears respond
to this change in pressure within a
sound field. Similar to a human ear,
microphones respond to the change in
air pressure created by
sound waves and convert
the fluctuations of pressure into electrical current.
An
electro optical
system used to pick up and convert a visual image or scene into an electrical
signal called video. The video may be transmitted by cable or wireless means to
a suitable receiver or monitor some distance from the actual scene. It may also
be recorded on a video tape recorder for playback
at a later time.
A
television camera may fall within one of several categories: studio , telecine,
or portable. It may also be one of several highly specialized cameras used for
remote viewing of inaccessible places, such as the ocean bottom or the interior
of nuclear power reactors. The camera may be capable of producing color or monochrome
(black and white) pictures. Most modern cameras are entirely solid-state,
including the light-sensitive element, which is composed of semiconductors
called charge-coupled devices (CCDs). Inexpensive or special-purpose cameras,
however, may use one or more vacuum tubes, called vidicon,
with a light-sensitive surface in lieu of the charge-coupled devices.
TELEVISION STUDIO CAMERA.
elevision is more concerned with the right visuals.
Without visuals the spoken words would
look meaningless.
It is the job of the scriptwriter to match the words
with the pictures and pass them on to the news readers.
Video Tape
The modern day’s video tape which records a story
visually. When colour TV came to
existence chromatic film came to be used . Video tape as it comes now is cheap,
light sensitive and also reusable. Video tape has totally replaced film. The
video tape is the standard materials used worldwide.
Video
Cassette
TV Cameramen usually use 20 minute cassettes because of
weight size of the videotape is ¾ inch technically known as U-Matic. Video
cassette is sealed at factories. Since the tape is not to be touched by bare
hand. Also it will cause to damage the tape also editing machines. Because all
the editing work is done electronically.
The sound and picture are on separate tracks on the tape. Thos enables video
editors rearrange them separately also make possible pictures and sound can be
edited separately.
The Television programs are provided in all the TV
channels that the requirement and tastes of viewers. The provision of
entertainment programmes in many forms such as songs, dances, cartoons, cinema,
and drama. The channels ensure that all classes and categories of their viewers
are altered. A videographer shooting for TV must frames his shot a bit smaller
than the TV screen to prevent any loose in the total frame when screened. The tape prepared by the videographer is the first
generation tape. When this edited and transferred to another tape . It is
became the second generation tape . Any copies made of this tape become the
third generation tape.
A cameraman uses shots to narrate his story visually.
Among these are the long shot the mid long shot
the medium shot , close up and very close shot.
Other
functions that are necessary to obtain high-quality pictures include gamma
correction, aperture
correction, registration, and color balance. Gamma correction is required
because the pickup devices do not respond linearly to increasing light levels.
It allows the camera to capture detail in the dark areas of high-contrast
scenes, essentially by “stretching” the video levels in those areas. Aperture
correction provides several benefits mainly related to an even overall response
to scenes with more or less detail. It also helps to improve the
signal-to-noise ratio of the camera's output video. Registration must be
adjusted on multiple-tube cameras to ensure that the separate red, blue, and
green images are precisely aligned on one another; charge-coupled-device
cameras are usually registered once, at the factory. Color balance must be
properly set on color cameras and must be consistent from dark scenes to bright
scenes, or there will be an objectionable tint to the camera output.
Studio
cameras are equipped with several ancillary
systems to enhance their operation. An electronic viewfinder
(actually a small television monitor) shows the camera operator what the camera
is seeing, making it possible to frame and focus the picture.
The
tally system
consists of one or more red lights that illuminate when the camera's picture is
“on the line” so that production and on-camera personnel know which camera is
active. Generally an intercom system is built into the camera so that the
director can communicate with the camera operator.
The
camera itself may be mounted upon a tripod,
but more often it is on a dolly and pedestal,
which allows the camera to be moved around on the studio floor and raised or
lowered as desired. A pan head permits the camera to be rotated to the left or
right and furnishes the actual mounting plate for the camera. The lens zoom and focus controls
are mounted on a panning handle convenient to the operator.
Telecine
cameras are used in
conjunction with film or slide projectors to televise motion pictures and still
images. Many of the usual controls are automatic so as to require less operator
attention.
Portable
cameras usually
combine all of the basic elements into one package and may be used for a multitude
of purposes. They have found their way into electronic news gathering for
broadcast television, and into electronic field production, where they can be
used for production of broadcast programs, commercials, and educational
programs. The units often have built-in microphones, videocassette recorders,
and batteries for completely self-contained operation.
Cameras used in
high-definition television (HDTV) are fundamentally similar in appearance and
operation to previous cameras. In fact, some modern cameras are switchable to
produce either a conventional output or an HDTV output. The conventional output
has a 4:3 aspect ratio raster and the scan rates match the 525-horizontal-line,
59.94-Hz-vertical-field-rate NTSC standard in the United States. When switched to HDTV
mode, the aspect ratio becomes 16:9 and the horizontal scan rate is usually
increased to either 720 progressively scanned lines or 1080 interlace-scanned
lines with a 60-Hz vertical field rate. See also Television;
T
The zoom line that cameraman
uses enables him to take either a long shot or very close shot without moving
camera but only by manipulating the lens.
The zoom lens are rarely used in TV news coverage. It is useful only for focusing on a man’s face and
fingers on documents. The pan shot
moves horizontally to the left or right as required.
The tilt shot covers the scene up or down. The pan shot
and the tilt shot are used while shooting conferences meeting or rallies.
They are not cared generally when the news values of a picture is not
important not its quality. It is generally the news writer who selects the best
shots available, both from the journalistic point of view and
also visually. In case of smaller stations or channels the cameraman
himself is expected to do the editing.
Use of Sound
Direct sound. Live
sound. This may have a sense of freshness, spontaneity and 'authentic'
atmosphere, but it may not be acoustically ideal.
Studio
sound. Sound
recorded in the studio to improve the sound quality, eliminating unwanted
background noise ('ambient sound'), e.g. dubbed dialogue. This may be then
mixed with live environmental sound.
Selective
sound. The removal
of some sounds and the retention of others to make significant sounds more
recognizable, or for dramatic effect - to create atmosphere, meaning and emotional nuance. Selective sound
(and amplification) may make us aware of a watch or a bomb ticking. This can
sometimes be a subjective device, leading us to identify with a character: to
hear what he or she hears. Sound may be so selective that the lack of ambient
sound can make it seem artificial or expressionistic.
Sound
perspective/aural perspective. The
impression of distance in sound, usually created through the use of selective
sound. Note that even in live television a microphone is deliberately
positioned, just as the camera is, and therefore may privilege certain
participants.
Sound
bridge. Adding to
continuity through sound, by running sound (narration, dialogue or music) from
one shot across a cut to another shot to make the action seem uninterrupted.
Dubbed
dialogue. Post-recording
the voice-track in the studio, the actors matching their words to the on-screen
lip movements. Not confined to foreign-language dubbing.
Wildtrack
(asynchronous sound).
Sound which was self-evidently recorded separately from the visuals with which
it is shown. For example, a studio voice-over added to a visual sequence later.
Parallel
(synchronous) sound. Sound
'caused' by some event on screen, and which matches the action.
Commentary/voice-over
narration. Commentary
spoken off-screen over the shots shown. The voice-over can be used to:
§ introduce particular
parts of a programme;
§ to add extra
information not evident from the picture;
§ to interpret the
images for the audience from a particular point of view;
§ to link parts of a
sequence or programme together.
The
commentary confers authority on a particular interpretation, particularly if
the tone is moderate, assured and reasoned. In dramatic films, it may be the
voice of one of the characters, unheard by the others.
Sound
effects (SFX). Any
sound from any source other than synchronised dialogue, narration or music.
Dubbed-in sound effects can add to the illusion of reality: a stage- set door
may gain from the addition of the sound of a heavy door slamming or creaking.
Music. Music helps to establish a sense of
the pace of the accompanying scene. The rhythm of music usually dictates the
rhythm of the cuts.. Conventionally, background music accelerates for a chase
sequence. Through repetition it can also link shots, scenes and sequences. It
may be a more credible and dramatically plausible way of bringing music into a
programme than background music.
Silence. The juxtaposition of an image and
silence can frustrate expectations, provoke odd, self-conscious responses,
intensify our attention, make us apprehensive, or make us feel dissociated from
reality.
Dynamic and
condenser mics
It's important to choose the proper mic type
and polar pattern. Dynamic microphones work on electromagnetic induction and
are comparatively simple in design
The manufacturers of some field recorders
recommend using condenser mics to provide a better signal-to-noise ratio from
the recorders' microphone preamps. Condenser mic design has come a long way,
but for pickup of loud sound sources like musical instrument amplifiers, a
dynamic mic is less likely to produce SPL overload and distortion because it
doesn't have an internal preamplifier.
However, many of the newer condenser
microphones have a switch on the case that can attenuate the signal by 10dB or
20dB for loud source pickup. Wireless mic body pack transmitters have a similar
attenuation switch inside the case, and this is typically used when the
transmitter is employed with an electric guitar or similar instrument with a
higher output than the microphone.
Pattern and
frequency
The second basic consideration is the
pattern. Any new microphone should come with a polar pattern the directionality
at various frequencies and the effect of pattern-changing switches. This should
always be accompanied by a frequency response graph.
Due to basic audio frequency physics,
microphones are less directional as the frequency goes toward bass.
Low-frequency sounds penetrate, while higher audio frequencies bounce off solid
objects like walls. In real-world use, microphones represent a typical case in
which you don't get something for nothing. There is always a trade-off, and
this is the essence of experience in microphone selection.
Omni directional microphones are less
sensitive to breath popping and sound coloration when used for close-up
handheld vocal applications, such as a reporter doing a standup in a high-noise
environment.
Cardioids microphones pick up less
background ambient sound, but require thicker (and more obtrusive) pop filters.
Also, they tend to have a proximity effect that emphasizes bass when held close
to the mouth. Singers often use this effect to their advantage.
Shotgun or hyper cardioids microphones
provide a tighter pattern but emphasize the proximity effect. For this reason, these
types are used in situations where the microphone can't be placed close to the
sound source.
Hyper cardioids podium microphones can help
prevent PA system howling by providing more gain before feedback, and this is a
typical case in which the correct microphone choice should come before twisting
any EQ knobs on the mixer. One hallmark of inexperienced sound operators is
that they tend to think that EQ knobs only turn to the right.
Levels and power
Microphone lines carry weak, tiny signals
that are vulnerable to inductive noise and hum from motors, lighting dimmer
packs and ground loops. Balanced lines help reject induced noise. However, the
best defense against background AC hum and other sound system trash is to kick
up the signal level at the earliest possible point with a preamp.
A good battery-operated preamp can sometimes
be placed inside a podium and supply the phantom power necessary for condenser
mics. Most include a limiter, and gain can be adjusted, usually in 5db to 10dB
steps. Many of the newer digital snakes also have preamps built into the snake
head, and these may be remotely operated. Any time a mic signal is being split
for separate house, broadcast or stage monitor feeds, the splitter should
include a direct path for mixer-supplied phantom power and a transformer
isolated path with a switchable ground lifter. Every sound kit needs to have
one because it can also be used to isolate powered speakers and other sound
gear that may get its power from an AC source incompatible with that running
the main mixer. Phantom power levels typically run from 12V to 48V, and the
higher the original sound levels, the higher the voltage on the phantom power
that may need to be used. Podium microphones for normal speech can usually get
by on 12V phantom power.
Coincident pair
Among the more frequently used techniques of
mic placement for stereo recording is the coincident pair using two cardioid
pattern microphones angled at about 90 degrees with the capsules placed as
closely together as possible without touching. This works particularly well for
recording sources that are spread out over a wide area, such as symphony
orchestras, studio audiences and crowds at sports events. (See Figure 1.)
Figure 1. Stereo Mics Select image to
enlarge
Parabolic mics used on football games can
also have a noticeable effect on the crowd ambience because they are normally
heavy on upper middle frequencies due to the size of the parabolic bowl.
Parabolic mic faders should be treated like an airplane throttle — smoothly up
and smoothly down.
Panel talk with
lapel mics
The electret condenser lapel mics used on
talk shows can be either omnidirectional or cardoid, but once again there is a
trade-off. With half a dozen guests on the set, cardioids sound less
reverberant but usually require pop filters.
ReplyDeleteThanks a lot for sharing!
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