If TV keeps an important place in everyday life, the arrival of the computer and the Internet has imposed changes on the small dormer. The cathode ray tube has given way to lighter and thinner replacements. And computer technologies like the network or the USB take a place. One thing has not changed: Buying a television is not always easy.


Today, we must understand the differences between HDTV and HDTV 1080p televisions, the differences between TVs Plasma and LCD, and of course the arrival of 3D television.  This TV guide may help you buying a new television.

HD TV, HD TV 1080p, and TNT HD

After the artistic vagueness of the beginnings, the acronyms on the boxes of the televisions were defined by the legislator.  HD TV is present on 720p TVs (with a resolution of 1366 x 768) and HD 1080p is displayed on 1080p televisions (with a resolution of 1920 x 1080).  These abbreviations also impose the presence of a TNT HD tuner, knowing that this one is compulsory on the televisions whose diagonal makes a minimum 66cm (26 inches).

 How big is your TV?


If the manufacturers indicate the size of their television in centimeters and inches, the latter unit comes back quite often and here are some conversions to get a quick idea: One inch corresponds to 2.54 cm, 32 “are 82 cm, 40” are 102 cm and 52 “are 132 cm. With these orders of magnitude, you can easily get an idea about your old television.

Take a step back


  • With a cathode-ray television, it was advisable to have a distance equal to four times the diagonal between the screen and itself.
  • The improvement in the resolution of HDTVs has allowed this reduction distance to be reduced: It is possible, in the same room, to have a larger television without loss of comfort, provided to use HD sources.
  • For SD sources, this graphic will allow you, at a glance, to know the ideal diagonal depending on the recoil you have.

The right resolution:

It is not always easy to know the resolution of all available sources. This condition, however, the recoil, but also the quality of display:


  • An HDTV can only work with a resolution identical to its resolution (1920 x 1080 in the case of a TV HD 1080 TV and 1366 x 768 for an HDTV TV): For all other sources, it will have to resize it.
  • One talks about upscaling when it is necessary to increase the resolution of the source (for example, to display a DVD on a television HD 1080 TV) and downscaling in the opposite case (a Blu-Ray that offers 1080p on an HDTV TV that only offers 720p).
  • At the bottom of the scale of resolutions are the SD sources – for Standard Definition – like DVD, TNT, but also a games console like the Wii. HD – High Definition – is divided into several categories.
  • Over the medium term, HD will prevail – whether via DTT, Internet TV or VOD offers.
  • For players above 82cm, even if you have a majority of SD sources, it is more interesting to take a TV HD 1080p TV.
  • The HD TV tiles are reserved for entry of ranges.

The movements, the obsession


Although making movements is not easy.  The guiding idea is simple: Create additional images to streamline images. These technologies (like MotionFlow at Sony or Motion Plus at Samsung) add 1 to 3 images between each real image. These technologies are useful for tracking fast scenes – a sports program for example. For movies, freaks prefer to disable them or set them to a minimum: The first have 100 Hz technologies that add an image, the latter have 200 Hz technologies that add up to three images.

Plasma or LED?

In the great tradition of modern technologies, two of them currently share the market and differ in their functioning: Plasma televisions and LCD televisions.

  • The Plasma


Plasma is supported by less and fewer manufacturers: Panasonic, Samsung, and LG are the last to manufacture these televisions. The operation of the Plasma is quite simple to understand: Each pixel in the image is composed of three gas cells – one per color. Using an array of electrodes, this gas will emit ultraviolet radiation – invisible to the human eye – that will be transformed into visible radiation (and colored) by coating each cell.

Plasma is distinguished by its fast reaction time, excellent color rendition. The Plasma also makes it possible to manufacture large screens at a reduced price.  The more bright the image, the more television will consume.

  • LEDs: The future for LCD TV?

The LED TVs are actually LCD TV that replaced their neon backlighting by LEDs. With regard to neon lights, LEDs are generally more energy efficient and provide better image quality. Constructors have two ways to position these LEDs – behind or on the edges of the LCD panel.


LED Direct

This category includes all screens with LEDs positioned behind the panel. It offers the best quality of images – especially for screens using RGB LEDs, a rather expensive solution – with good light uniformity, good color rendering and for some slabs, Local Dimming. Vary the intensity of the LEDs per zone and improve the contrast of the images: The dark areas will be dimly lit in contrast to the luminous zones.

LED Edge

A LED Edge TV incorporates LEDs in its edges. The quality of images produced is superior to conventional LCD TV but lower than LED Direct TV: It is not possible to take advantage of the Local Dimming with LED Edge TVs and the arrangement of the LEDs can cause some problems of luminous homogeneity. In contrast, this technology offers the finest slabs:  Whenever a builder beats a record of finesse, it does so with an Edge LED panel.


What connections for your TV?


For HD sources, HDMI is the standard interface. The HDMI is currently in version 1.4, compatible with 3D but also in some cases the network data.  To connect a computer – not necessarily recommended with a Plasma screen – the VGA jack is the most common way to do so, although some graphics cards now have HDMI output. Also in the computer area, the USB port allows you to view photos or play music directly from a USB key. The Ethernet port allows the same thing, but by directly reading the files on your computer! This Ethernet port also makes it possible to take advantage of the online services of manufacturers, such as Internet access, a weather channel or the display of Youtube! / DailyMotion directly on TV.

It’s the world of 3D!


Foreign channels have already announced their intention to broadcast in 3D and some sporting events should be filmed in 3D. This evolution will require the purchase of a compatible deck, which will be able to play all the already existing Blu-ray movies (as well as DVDs): To enjoy 3D, it will take a film intended for (like the famous Avatar of James Cameron). It should not normally be necessary to buy two versions of the film to be able to play a 3D movie on a deck not compatible with 3D, but the situation is at the moment rather vague.

With or without glasses, many technologies in the competition.

To make a 3D image, manufacturers “content” themselves with the natural functioning of our brain and our eyes: Each eye receives an image slightly shifted from that of the other eye, and it is by combining these two images that the brain is able to perceive the distances of the world around us.


For a 3D movie, this is exactly the same way: The camera will shoot a scene from two slightly different points of view. This is simple (and we found 3D movies from the beginning of the century!), But the application outside a Cinema is another matter.