How Television Display Works and Projects Video Image Production

TV Production

Video Display


As we have discussed this before in my previous posts, that the process of video field production and the process of television image generation, are like as motor and generator. Your home TV set works in much the same way as the camera image sensor, except it reverses the process. That is, instead of turning light into electrical energy as the CCD and pickup tube does, your receiver turn electrical energy into light. This is accomplished by scanning the television picture tube with an electron beam. At the back of the picture tube in your television or receiver set is an electron gun, which shoots an electron beam at the inside of the face of the picture tube. The picture tube is coated with the photosensitive material that glows when it is hit by the beam of electrons. A large blast of electrons causes it to glow a lot; a small blast causes little action.





Lines and Frames of Television Scanning


The video image is composed of a number of frames and lines. Because we normally think of the TV process as existing in time, we can measure the frame rate of television rather easily, or you can understand this as that these frames are units of projection and that how much the clear view result is. In many countries, there are 30 frames of video information in per second, and each one of those frames is composed of 525 lines of information. Starting with line number 1, the beam moves across the picture tube until it gets to the end of that line. Then the beam automatically shuts off, returns to the other side of the picture tube, drops down to the line number 3, and scans across that. Once again, when it reaches the end of the line, it automatically shuts off, drops down to line number 5, and repeats the process all over again. When it gets down to the bottom of frame or last line, it shuts off, returns to the top of the picture, and scans the even number lines like 2, 4, 6, … and so on. This process is known as 2:1 interlaced scanning. First the odd number lines are scanned and then the even ones. Each time gun reaches the bottom of the picture, it has completed one field, or 262.5 lines, of information. A complete frame of information (525 lines) is composed of two individual fields: one is of odd numbers and second is of even numbers. The reason of this system of interlaced scanning is simple. The photosensitive surface on your picture tube glows for a very short time when the electron beam hits it. If beam started scanning from the top of the frame and continue down to the bottom, by the time it got there the top of the picture would already have faded to black. To keep part of the picture from fading out or flickering, the lines are interlaced. As a result, the picture maintains its brightness throughout the program. Incidentally, the 525 lines per frame standard characteristic of U.S. television is an arbitrary standard. That is, the system could have more or less lines still function. Indeed many other countries use 625 line systems, which actually provide greater detail than 525 lines. The system used in U.S. and Canada was adopted as the represented the major U.S. electronic manufactures at the time TV was invented. The Federal Communications Commission (FCC) adopted the NTSC recommendations for the 525 line 30 frame television standard in 1941.










Controlling of Video Signal
Horizontal and Vertical Synchronizing


As we have discussed, each frame of video information is constructed by combining picture information and synchronizing information. Among the most important synchronizing control pulses are horizontal and vertical sync and blanking pulses. These pulses are generated by a sync generator that can be located as an integral component inside the camera or as a separate component outside the camera. The horizontal sync and blanking pulses control the timing of each line of video information, the vertical sync and blanking pulses controls the timing of each field and frame of information. Essentially, each line of information begins with a horizontal sync pulse and ends with a horizontal blanking pulse. Similarly, each field begins with a vertical sync pulse and ends with a vertical blanking pulse. Thus you can see that for each frame of video information there are 525 lines of information and 525 horizontal blanking and sync pulses. These 525 lines are arranged in two fields of information along with two vertical blanking and sync pulses. The sync pulses not only allow the system to work but also this information becomes extremely important when we get to the area of video tape editing.





Internal and External Sync


When sync pulses are generated within the camera, we refer to the sync as internal sync. When sync pulses are generated outside the camera, we refer to the sync as external sync. When a single camcorder is used for video field production, the horizontal and vertical sync pulses are produced internally in the camcorder itself. Most single-camera field production units fall into this category. In more complex multiple camera field production system, which include a video switcher and several cameras operating simultaneously, all camera must scan synchronously. To accomplish this, they all must have the same reference to horizontal and vertical sync. In such a situation, an external sync generator is used to regulate the timing of the all the camera source. Sometimes, the sync pulses generated by one camera can be used to drive the signal of another camera through a process called gen-lock. In this process, the second camera senses the incoming sync pulses from the first camera and then creates its own video signal synchronously with the other camera. The Video Waveform As this discussion has already indicated, the video signal is somewhat complex because it contains not only picture information but also synchronizing information. The picture information alone is referred to as a noncomposite signal. When the video information and sync are both present in a signal, it is referred to as a composite signal. Let’s continue our discussion of the video signal by talking more specially about the black and white picture signal. Black and white television presents a range of brightness only, elements in the picture are somewhere between white and black. This range of variation between white and black, or between the brightest and darkest parts of a scene, can be seen in the video waveform, which shows us what the video signal actually looks like. Figure below shows the components of one line of information of a typical video waveform.

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Video Field Production Camera and Controls

Video Field Camera
Electronic Image Reproduction

At the center of all video field production systems is the portable video camera. A marvel of modern electronics, the video camera is charged with the responsibility of producing the electronic signal. All video cameras have a number of standard components, including an image sensor, viewfinder, camera control unit, and lens assembly. This post will focus on portable video cameras and on the function of the first three components listed above. We will look at lenses in our upcoming posts.





Function and Types of Camera Image Sensor

The most important component of the video field camera is the image sensor. Its function is to change light into electrical energy. Technically speaking, the camera image sensor is an optical-video transducer, which simply means that it changes incoming light (physical input) into an electrical video signal (electric output). By way of comparison, microphones are also transducers-they change incoming sound waves (physical input) into an electrical audio signal (electrical output). Two types of camera image sensors are now in use: CCDs (charge coupled device) and vacuum tubes (usually simply referred to as pickup tubes)



CCD (Charge-Coupled Device) Principles

A charge-coupled device (CCD) image sensor is a solid-state semiconductor that converts incoming light into a video signal. In the CCD, incoming light strikes a layer of metal oxide or silicon semiconductors where it is converted into an electric charge. Each one of these conducting points is referred to as a pixel. The number of pixel in the chip determines the amount of detail or resolution; the camera will be capable of producing. These pixels, or picture elements, are arranged in precise horizontal and vertical rows on the chip. High-quality CCDs often contain more than 300,000 individual pixels, or picture elements. The camera lens focuses the scene before it on this array of pixels, each of which is of reproducing one tiny part of the picture. After the incoming light is converted into an electronic charge, it is transferred and stored in another layer of the chip, and then the information is read out one frame at a time in a line-byline sequence in conformity with normal television scanning rates. CCDs are very small. Typically, the image sensing area of the chip is either 1/3”, ½” or 2/3”, measured diagonally. CCDs are much smaller, lighter, and more reliable, and they consume less power than traditional pickup tube type systems. Because they are much more rugged than conventional pickup tubes, CCDs have largely replaced pickup tubes in cameras and camcorders designed for home video market. They are also used in most professional cameras and camcorders designed for remote use, where the need is for a durable camera that will stand up to more physical abuse than is typically received by a camera used in a controlled studio environment. Indeed, CCDs may soon replace pickup tubes entirely as the imaging device in all consumer and professional video cameras.



Electronic Shutter

All CCDs cameras are equipped with an electronic shutter. The electronic shutter controls the amount of time that the incoming light hits the photosensitive layer of the chip. In recording situations where the recorded image tends to flicker or become blurred because of high speed movement of the subject in front of the camera, shutter speed can be increased to reduce these picture artifacts and improve the sharpness of the image. Although shutter speed position of OFF, 1/60, 1/100, 1/250, 1/500, 1/1000, and 1/2000 are fairly common on professional cameras and camcorders, the number and range of shutter speed positions available will vary depending on the quality (and cost) of the camera or camcorder.



The Camera Pickup Tube

Vacuum tubes have been in use since television cameras were first invented, and although they have been largely replaced in new camera designs by CCDs, pickup tubes continue to be used today in few cameras particularly large studio-type cameras and some cameras designed for high-definition television (HDTV). The process through which light is changed into the video signal by a pickup tube is one of the most fascinating things about television. Although it may seem complicated at first, it is really quite a simple process. The pickup tube in a video field production camera is a small vacuum tube usually 3” or 4” long and ½”, 2/3”, or 1” in a diameter. The tube has several main components. The tube itself is made of glass. Attached to the inside of the glass face of the tube is an extremely thin, transparent photosensitive coating. Next to this is a layer of photoconductive material. Immediately behind the photoconductive layer is a target, which has a slight positive electrical charge when the camera is turned on. Light from the scene that is being recorded is focused by the lens of the camera onto the face of the pickup tube. It passes through the glass and the photosensitive coating, onto the photoconductive layer. As light hits the photoconductive layer, it causes the charge on the target to change in proportion to the relative intensity of the light. The video signal is produced as the target is scanned by the beam of electrons. The beam of electron is emitted by the electron gun at the back of the pickup tube. The electron beam is focused on the target and scanned it in a series of horizontal lines. Each line of the picture is composed of about 500 pixels, or bits of information. Bright spots on the photoconductive layer change the charge on the target greatly, and when the particular spot is scanned by the electron beam, a great number of electrons pass through the target than pass through the places where the image on the photoconductive layer is darker. These changes in the charge on the target plate produce the video signal.

read more:
The Production Company
Working of Production Company
Types of Production
Initial Components of Video Field Production

Initial Components Of Video Field Production

Initial components of video field production and how to control the technical components of production should be the first thing on which the video field producer or director ponder upon.

Video field production combines an understanding of the technical factors of production with the aesthetic factor of production. Technical factors relate to developing an operational understanding of the way in which equipment functions. To work successfully with portable video equipment, you must understand how the equipment works. This does not mean that you need to be engineer or understand all of the electronic and physical principles that govern the operations of the equipment. What it does mean is that you must have an understanding of the way in which the system operates, way in which different technical elements interrelate and the way in which you can control the technical components of production. It does mean that you need to have basic understanding of what the video signal is and how it can be controlled. All video equipments operates on similar principles, I stresses fundamental underlying principles of operation. Because underlying operational principles vary little among brands of equipment.

Many handbooks on video production are nothing more than manuals of equipment operation. However, it is my position that one must know not only how to manipulate the equipment but also how to manipulate the medium in which one is working: video. This brings us to the area of media aesthetics. Aesthetic factors throughout this text, refers to production variables and the way in which they can be manipulated to affect audience response to the video message.

We see the process of video field production is a combination of technical factors and aesthetic factors. Whether you are engage in video production for personal, artistic, educational, or broadcast uses, the requirements of the technology and the medium must be considered. The fundamentals of production and the production process discussed here will be helpful to you, no matter what type of video production you are engaged in.



Creative problem solving, if there is one phrase that expresses the idea of what is at the center of video field production, it is creative problem solving. Communication via video means, that the producer/writer/director must understand the medium and how to use it. Finding the appropriate techniques to effectively express the idea and content of the program presents problems that must be solved creatively.

Video field production also presents a unique set of logistical problems. No two days of shooting in the field are ever quite the same because no two locations are ever the same. The ability to deal with the range of problems encountered on location is the mark of the successful field production person.

Finally, video field production presents a set of unique technical problems. People involved in field production simply must know more about the technical side of video production than must their studio counterparts. All manner of technical problem arise in the field, and field producer must be able to anticipate and avoid them or correct them when they arise.

For me, the process of creative problem solving is what makes field production so exciting and enjoyable.


read more:
The Production Company
Working of Production Company
Types of Production
Camera Working and Parts

Production Types

The world of video production has changed significantly as compare to early production methods. Video field production is now well established as one of the three major modes of production (studio production and computer-generated imagery are the other two), increasingly, video production is field production, rather than studio, inside a television station. This kind of production depends on reliable, portable video production equipment and on the ability of skilled production personnel to use it, this blog will cover all the aspects such as single-camera video field production on the equipment that makes it possible and on the production techniques and strategies that can be used to create effective messages through the use of this relatively new technology.Over the past three decades, a seemingly endless stream of technological developments has made video equipment smaller, less expensive, and accessible to more people, as a result of the portability and accessibility of this new technology video has found a host of new uses. Portable video is increasingly being used for personal expression, for independent production, in educational institutions and corporations, as well as in the broadcast arena. These changes revolutionized the field of video production. The introduction of lightweight, portable video field production equipment has moved video production out of the studio and into the field, and the development and refinement of reliable, inexpensive editing systems has made postproduction editing more important than ever in the video production process.Today, the personal computer is finding increasing use as a video production tool and as a means of displaying multimedia programs that integrate video with sound and text. The development of the new ¼’ digital video cassette recording format, aimed at both the consumer and the professional markets, promises to usher in a new age of digital media production and democratic communication.One other comment deserves to be made here. The focus of blog would be on video field production, but this needs to be qualified. I will primarily concentrate on what some writers have called “small scale” field production because this is a type of production that most student and home video producers as well as many independent and broadcast producers are most often engaged in. I am concerned with production that involves a minimum amount of field equipment and a small crew or team. The video producer who has access to a camcorder, a few microphones, a small lighting kit and a simple editing system will find his way in this level of production. While I do provide some descriptions of large-scale productions and production equipment, this is not the primary focus. We should note here that small-scale production does not mean amateur production, because the line between broadcast-quality production and equipment and non-broadcast production is a thin one indeed.


read more:
The Production Company
Working of Production Company
Initial Components of Video Field Production
Camera Working and Parts

Production Company Working

To start a production company or production house is like starting any other business, as it says house so it should be on your top priority to acquire your fix assets like office, camera, lights, microphones, and edit machine, for beginners can always rent their equipment from any other production house. The job of a production company is to evaluate the means and execute the production using the medium of performing arts, film, radio or a television program to convey the message to the audience, which is then again bring to the evaluation to see the results through audience feedback to the producer. Typical production company producer may find a story from books, plays, other films’ inspirations, true stories, original ideas, etc.. Once the theme, or underlying message, has been identified, a synopsis will be prepared. Next a treatment or development is prepared. This is a 35 to 40 page description of the story (in case of teleplay the script should not exceed more than 50 pages of script with dialogue and screen play), its mood and character with dialogue and period of time. The screen play is then written over a period of several months.
Production company then may shot the pilot(a short 10 minutes video containing clips about the story or movie) and present it to potential financiers. If the pilot is successful and the movie is given the green signal, a financial backing is offered, typically from film studios, tv channels or independent investors. A deal is negotiated and contracts are signed. The other way is that the production house puts its own capital in production and after shooting, editing, sells the finished product to those precisely told people.
The owner/s of the production company ( it is common for actors or directors to form their own production companies so they can have more control over their own careers) prepare the pilot with the help of already hired production team which are employee to the company or he may require to outsource the work to be done for the project. The production team is based on the nature of film or project and the budget; depends on the size and type of crew required for the project. Typically, the principal role involved in producing single-camera remote production is called the producer, who is responsible for the overall organization of a production and for delegating responsibility to other members of the production team. The director is primarily responsible for the acting element in the project and managing the creative elements. The assistant director (AD) manages the shooting schedule and logistics of the production including other tasks. The camera operator or videographer or sometimes called shooter is responsible for the visual treatment of the subject matter as well as for the physical operation of the camera. The production assistant is responsible for monitoring audio aids and to set up the lights and providing other general production support. The location provider or manager; since most of the scenes are shot in the predictable environment of a studio but occasionally outdoor sequences will call for filming on location, the production manager manages the production budget and production schedule, he/she also reports on behalf of the production company to the executive producer or financers of the film. The art director manages the art department, which makes production sets and the storyboard artist creates visual images to help the director to communicate his ideas to the production team. the other team members are, the makeup artist/ hair stylist, audio engineer who records and mixes the audio and dialogue, the composer creates the music for the film, the choreographer creates and coordinates the movements and dance, typically for musicals.


Some films also credit a fight choreographer or action director, and the videotape editor who is responsible for executing the producer’s or director’s vision in the process of postproduction editing, the editor has primary responsibility for physically performing the edits, depending on the role of the producer or director, the editor may have much or little responsibility for actually making editing decisions. In many cases, work roles overlap and entire production may be produced by two or three people, with each assuming several responsibilities during the production.
Production company may have several producers or directors to accomplish the job, the person who is overall responsible is known as executive producer, who appoints people and put his capital on the production process and for above line talent which includes director, writer, etc.

The production process is divided into three stages, one is pre-production, which is before the casting and designing sets, includes work on plot, script, and budget estimation, days of shoot, discussions on the project and ideas exchange between director, writer, producer and other team members. Then comes production in which the film is being shot and the post-production which happens between the actual filming and the completed film it also includes edit, color correction, animations, etc.


read more:
The Production Company
Types of Production
Initial Components of Video Field Production
Camera Working and Parts

The Production Company

Welcome to The Production Company. This site serves as to simplify the working and types of production companies which helps to setup an understandable chain to all who want a start as TV, movie or theater producers. If you have questions not covered in Production Company blog, please feel free to email your questions to mudbbir@gmail.com



read more:
The Production Company
Working of Production Company
Types of Production
Initial Components of Video Field Production
Camera Working and Parts