Cheap HDTVs

This time we want to give you a more detailed explanation of the symbols that are commonly found in specifications for High Definition TVs.

Unlike standard TVs, High Definition TVs aren’t standardized. When you buy a standard TV, you only consider price and size. In our parents’ time, you also had the option between color and black and white TVs (strange and archaic as it may sound to our children).

In any case, the quality of the image wasn’t in question. In fact, “quality of image” means “size of the screen” when you’re dealing with standard TVs.

Not so with High Definition TVs. Each manufacturer produces High Definition TVs that work in similar but different ways. That’s why you get specs that say 1080i when they talk about their image resolution.

If you don’t know much about High Definition TV technology, you might decide to ignore these specifications and just buy a HD TV of a size that you like. However, if you want to know what these specs are, here I’ll explain them a bit.

Let’s start with the letters p and i. These refer to the scanning method of the HD TV. The scanning method is the way the HD TV displays the image on the screen.

A few years ago, the amount that could be sent over cables or transmission wasn’t as big. This meant that the quality of the image suffered because not much information could be sent.

As a way to solve this, engineers came up with an original idea. Instead of sending the whole image, broadcasters would send only half of it at a time. So, you actually got only half of the video broadcasted at the same time. The other half would be broadcasted a few fractions of a second later and the cycle would repeat itself. Because you can’t detect images sent at fractions of a second, you don’t notice that part of the screen is static while the other part changes. This technology is called interlaced video and is referred by i.

As technology advanced, the amount of video that could be sent (especially by making it digital) improved. No longer did you have to send half after half of the screen. You could now send the whole screen at once. This is called progressive scanning and is represented by a p.

However, while progressive scan is superior, the difference is only noticeable if you have two screens side by side with objects moving really fast. Otherwise, any of these will certainly look much better than any standard TV display.