A Technical Presentation of Television

Behind the Screens: A Technical Presentation of Television

Would have our grandparents believed that we'd be able to see what occurs on the other side of the planet in real time? Take a look at the techniques behind this process.
Mass Media includes the written press, the audio-visual means and multimedia systems. Newspapers, radio and television claim to offer people information concerning the political, economical and cultural life of society, concerning education, health, international relationships, public persons, and so on. Moreover, mass-media circulates opinions and viewpoints regarding public interest events. At the same time, it informs citizens regarding the way in which public institutions work. Because of this reason the press was proclaimed the fourth state power.
The written press is the oldest type of mass media communication. It comprises: magazines, also called gazettes and journals, or daily magazines. They are issued every day. Their role is to keep the public informed about the newest events. Depending on the way of diffusion, we can classify them as central, regional or local gazettes. Depending on the type of information given, the majorities have a general profile; others are specialized in sports and economic news, and so on. There are also many magazines and publications with a weekly appearance or which are issued every month, every semester, and so on. Because of that they are also called periodicals. Most of them are specialized or they are addressed to a target audience such as youth, women, IT experts, sports lovers, rock music fans, and many more.
Among the audio-visual means we can mention the radio, which renders sound messages, and the television, which communicates through sound and images. Depending on the area of reception, we can speak of national and local televisions. Depending on its owner, there are public and private televisions. Private televisions have mostly a commercial character; there are many commercial sports intercalated among the TV programs. TV programs are broadcasted in ether through satellite or relays. Multimedia systems are communication and information means using computer science.
Television is the mass communication medium with the greatest impact on our society. Technically speaking, it is defined as a procedure of decomposing, distance broadcast and than recomposing images. Television was invented between the two World Wars and developed as part of the great mass media only at the end of 1940, first in the United States and then in Europe.
A child of radio and cinematography, television has long preserved a language which, being original, allows it to take an essential part in the media system. When it appeared, at the beginning of 1930, it suddenly caused the surprise of the first observers, who were fascinated with a sort of "tele-presence" allowed by this uncanny media form. Analysts state that television is a documentary means which increases considerably radio's power of information, adding hearing to vision. Television work is based on selenium's capacity to transform luminous energy in electrical energy and vice verse, because of the electrons' radiations.
The analysis of the image can be done with the help of an electronic camera, which converts the optic image in a correspondence image. For that, a fascicle of electrons scans behind a screen which is made of a multitude of luminous points, disposed on 525 lines which make up 25 images (photogram) per second. The analyzed image is transformed in an electric signal which will be broadcasted through radio diffusion. Upon its reception, the image is reconstructed through the same procedure. The screen of a television is made of a plurality of fluorescent points, excited by modulating the electronic signals, and the luminosity being rendered by the cathodic tube's voltage. The camera seems to imitate quite in details the human eye and is the main tool in the television industry. A camera essentially serves for catching luminous signals, electromagnetic radiations and to transform them into electric signal.
If the images that are found in the field interest of the camera can suffer changes in time, space and color, the resulting electric signal varies only in time. Electromagnetic waves by which the television signal is broadcasted have ultra short wavelengths (from 10 meters to 0.1 millimeters), or extremely high frequencies respectively (from 300 Megahertz to 3000 Gigahertz). Like in the case of the radio, there are two main compartments: the studio and the technical direction. The studio is an inner space inside the television building in which the broadcast is being performed. There, the presenter realizes the program, being filmed by the cameramen. Each image taken by the video cameras inside the studio is visible on a monitor in the technical direction department. All the technical aspects including the software necessary to make a movie or clip, any kind of required arrangement in order to obtain the desired result takes place in this technical studio where the video takes its final shape.
In broad lines, this is the mechanism that enables us to see everything that goes on around the world, amazing advancement, isn't it?