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Thursday, October 31, 2013

Which TV should I buy


Have you found yourself at your local electronics store looking for a new TV and you are met with a bunch of similar looking TVs, some costing about 10 times the others. They have all these fancy logos to justify their outrageous prices. Plasma, LCD, LED, OLED. 3D, HD, FULL HD, UHD. And you are like ... What's all this , I just want a TV.






Once upon a time TVs used CRT technology. Well they actually still do.  These are the TVs with the common bump at the back. Its a cathode ray tube (CRT) that emits particles onto the screen for scanning and thus creating the picture. The image is refreshed about 30 times a second so as to keep it to keep it updated.
CRTs have been around since time in memorial and they don't seem to be going anywhere. Personally I prefer their picture quality to cheap plasmas and LCDs.



If you thought plasma and LCD was one the same, fear not because you are probably not alone. I have seen publications advertising something like "LCD plasma TV". So what are the differences you may ask and which one is better?

There are mainly four technologies which are used for flat screen manufacturing. These are Plasma,  LCD and OLED. LED even if marketed as a stand alone technology, is just a back lighting method used in today's LCDs.

So whats the between the above mentioned technologies. In the following explanations you may encounter these terms:
 RGB (Red, Blue, Green). these are the primary Light colors that make up light. Varying the intensity of these color combinations leads to production of different colors by the pixels. An image is made up of many pixels.

pixels of the ear
Resolution: This is the number of pixels on the display. The more the pixels, the better the image quality.


Pixel density is the number of pixels per inch. This means that a smaller TV will have better image quality than a larger TV given all other factors constant.




Refresh rate: This si the number of times an image is drawn on the screen in one second. The higher the refresh rate, the better the image quality. High refresh rate results into smoother video.



Plasma Display Panels (PDP)


This technology utilizes millions of small cells containing electrically charged gases and plasma. This gas lights up when you run electricity through it. Different phosphors are used to achieve different colors.  Each pixel is made up of three cells comprising of the primary light colors RGB.

Plasma televisions have blacker blacks than LCD as they can completely turn of black pixels completely which allows for better contrast. It has wider viewing angles compared to LCD and less visible motion blur for fast moving videos due to higher refresh rates. Plasma displays also produce better colors as they are able to control every red, green and blue pixel individually.All the disadvantages like screen burn in where an image would be permanently burnt onto the screen are history as they no longer affect new models.



LCD TVs 


LCD stands for Liquid Crystal Display. This technology uses millions of segments filled with liquid crystal. LCD panels are typically composed of two sheets of polarized material with a liquid crystal solution between them.

So when an electric current passes through the solution, it causes the crystals to align so that light can or can’t pass through. After the light goes through the crystal gates, it then goes through a color filter that either makes it red, green or blue and we are back to the RGB things again.


LED TVs


LCD displays are either CCFL-backlit or LED-backlit, CCFL is the normal back light which isn't anywhere as good as the LED back light. LEDs produce darker blacks and produce brighter, more vivid images. This is achieved by the fact that unneeded LEDs can be turned off completely to produce deeper blacks and they are individually very bright when turned on.

So what does this mean about LED TVs. For those who might have gotten confused somewhere or everywhere along the way, it means that LED TVs are just another type of LCD. The back light technology is the only difference.

LCD TVs are less reflective because of the surface cotting, so you see more TV than the world around you. LCDs. They are more likely to live a longer life than a plasma.


OLED TVs


OLED stands for Organic Light-Emitting Diode. This is the latest technology used in TVs today. OLED technology utilizes  a layer of organic material which produces light when electricity is applied. Each individual pixel in an OLED screen has its own individual red, green and blue sub pixel. Each sub-pixel generates its own light and therefore no need for a back light.

It is for this reason that OLEDs have the best viewing angles, best contrast ratios as black pixels are completely turned off. They also have very vivid colors as each individual pixel produces each own color. OLEDs are however very expensive as they are very difficult to make as of now.

NB: This is the same technology as AMOLED. or Active Matrix OLED.


Display Resolution


So that's it for the display technology. But you have to watch out for the display resolution. This is the number of pixels available on screen. It is normally written as a multiplication problem for those who attended math class. This is Horizontal times Vertical. The answer is the number of pixels. The higher the resolution, the better the image quality.

These are some of the common display resolutions
FULL HD or 1080p or 2K. This is 1920 x 1080

HD or 720p This is 1280 x 720 or  1366 x 768

UHD or Ultra High Definition

4K UHD  is  is 2160p (3840 × 2160). This is 4 times more pixels than FULL HD.

8K UHD  is 4320p. (7680 x 4320). This is 16 more pixels than FULL HD.


3D TV


What is 3D. Our eyes or the eyes for anything out there except cyclopes view the world in 3D. This is the ability to view depth. and actually be able to judge something to be close to you or far away from you.

In other words you can see the image come out of the TV. 2D TVs or for that matter anything 2D achieves this by making far objects to appear small and near objects to appear larger.

 The basic concept is to align two images slightly apart overlapping each other. This is something you can achieve by crossing your eyes. One image for each eye. Both of these images are directed to the intended eye using special 3D glasses and therefore confuse the brain to create a 3D illusion. Now you know why God gave you two eyes.

Note that some 3D technologies do not require glasses.




SMART TV


Smart TVs are TVs with built in software. These TVs are generally over sized smartphones or tablets. They have on board storage such as hard disks. Can connect to the internet without need for a computer and can be programmed to do many things. They have support for Apps and so on.

I don't think I need to say anything about the TV size. You just have to buy the largest your money can buy you after considering the above factors.




So now you must be asking yourself, which one is better and which one should I buy. It comes down to your personal needs and your budget. The best TV is the most expensive and vice versa. Plasmas are generally better than LCD in a closed environment without outside light. They are however not so good at living a long life. However newer LCDs that are LED backlit give you a really good picture and are good enough for the long run. OLEDs  have the best image quality, I mean they are the best. But are very expensive.

Another very important factor you need to consider is the connectivity options on the TV. These are the outputs and inputs such as HDMI, VGA and those common RCA connections on the TV. The more you have the better. So the next time you find yourself in a TV shop or when shopping online for a TV, you should at least have an idea about what you are buying.