Friday, 30 March 2012

TELEVISION PRODUCTION TECHNOLOGY

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




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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.

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