DTH True HD VS Upscaled HD

Pixels Differnace 

While comparing DTH services, one of the many metrics used is the number of HD channels offered by a DTH operator. It's interesting to know that a good number of these so-called HD channels aren't actually HD at all. Then, why are they marketed as HD channels? Let's try to fathom it by understanding the fundamental difference between standard definition (SD) and high definition (HD). Standard definition is generally referred to the vertical resolution of 480 pixels (in India). This essentially means that for vertical resolution of 480 pixels there are 640 pixels horizontally when the standard aspect ratio is 4:3. For high definition, though, the vertical resolution is 1080 pixels that has corresponding horizontal resolution of 1920 pixels when the aspect ratio is 16:9 (default). Hence, HD picture will always be sharper and carry more detail than its SD counterpart. 

Aspect Ration Diffrance 

When we say that a programme is in true HD, then we are assuming that it was created as and transmitted with the following characteristics: 1080p or 1080i for 16:9 aspect ratio. On the other hand, upscaled HD content doesn't meet the above requirement as it was shot in standard definition (480 pixels vertically) but by using complex algorithms (by the set top box) was scaled upwards to get 1080 pixels vertically. This is known as upscaling and can make the picture look better (or sometimes, horrible) on an HD TV.

Nowadays, most content is actually shot in HD and the number of true HD channels are increasing rapidly. Let's compare various DTH services on the basis of HD channels they offer. Reliance Digital TV offers 300 channels in total and upscales all of them to 1080p quality! Tata Sky offers 68 channels in HD quality and Videocon d2h has 45 true HD channels (asli HD, as they call them). Dishtv offers 45 channels in HD quality and Airtel digital TV has 33 true HD channels as of now. Make sure that you subscribe for true HD channels to get unadulterated television viewing experience.