Basic Comparison: AnalogTV, SDTV, EDTV and HDTV

There was a time when we only had one option when buying a TV, that is, conventional analog TV or CRT TV. But today we have so many options. First, we have our conventional CRT (cathode ray tube) television. Along with this we have new options like HDTV, EDTV and SDTV. But what is right for you? What are the main differences between them? Let’s try to understand the basics of each of them.

Conventional analog television:

First of all, let’s talk about our conventional CRT TV. CRT TV video displays contain 525 lines of resolution, even though only 480 lines are displayed. These lines are painted using the “interlace” technique. In this technique, it first paints all the odd lines from 1 to 479. Immediately after that, it paints all the even lines from 2 to 480. This standard analog TV format is represented as 525 interlaced or 525i, this is also represented by the term ” 480i”. . The screen aspect ratio is 4:3. This TV has a built-in NTSC tuner, so by default it cannot tune in to digital TV broadcast.

Analog television:

With NTSC, broadcast has been dominating for the last 50 years. But it is time for DTV (Digital TV) to gradually replace Analog. Digital television is a new type of broadcast technology that offers television with cinema-quality images and Dolby digital surround sound, along with a variety of other enhancements. This digital TV works with ATSC transmission instead of NTSC. Currently there are three types of digital broadcast signal: SDTV, EDTV and HDTV. The aspect ratio for DTV is 16:9.

SDTV:

Like analog television, SDTV also 480i. Here’s the advantage compared to Analog: SDTV can receive digital broadcast signals.

EDTV:

Until now, TVs with 480i resolution have worked fine. This is because TV sizes are limited to 19 or 20 inches. But the limitation of 480i resolution arose when the same technology is applied on a large screen. Interlacing techniques do not work for larger screens. Visible scan lines and irregularities are annoying. The best solution is to avoid interlacing. Initially, interleaving was invented to save transmission bandwidth. But with today’s technology, transmission at a much higher speed is possible. Therefore, there is no need for interlacing. It is possible to paint the lines sequentially from 1, 2, 3… up to 480, this is called “progressive scan”. With this technology using the same 480 lines of resolution, we can get better video quality. This 480 lines progressive scan technique is commonly known as 480p. This concept in the consumer market is known as Enhanced Definition Television or EDTV.

Both SDTV and EDTV also receive 16 by 9 feeds along with the 4 by 3 aspect ratio.

high definition television:

Although we have the digital broadcasting system SDTV and EDTV, the most attention was drawn towards HDTV. The main advantage here is a higher number of scan lines on the screen. HDTV comes in three flavors 720p, 1080i and the newer 1080p. As its name says, the first resolution shows 720 lines progressively and the second shows 1,080 interlaced lines. If we compare these two, we can say that both are good. In general, 720p is more appropriate for fast action, since it uses progressive frames; alternatively, 1080i is very good for slow moving pictures (this is probably why slow moving movies can be seen in most HDTV showrooms). 1080p, on the other hand, provides an image resolution of 1920 by 1080 pixels. This one provides the best display compared to others. This is because 1080p contains a maximum number of pixels compared to other varieties, plus 1080 progressive scan lines that are considered better than interlaced.