There was a time when we only had one choice 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 the right thing 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. The video screens of CRT televisions contain 525 lines of resolution, although only 480 lines are displayed. These lines are painted using the “interlacing” technique. In this technique, it first paints all odd lines from 1 to 479. Right after that, it paints all 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 aspect ratio of the screen is 4:3. This TV has a built-in NTSC tuner, so by default they cannot tune in to digital broadcast television.

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

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

EDTV:
Until now, TVs with 480i resolution 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 the big screen. Interlacing techniques don’t 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 to interlock. 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 broadcasts along with the 4 by 3 aspect ratio.

HDTV:
Although we have the digital transmission system SDTV and EDTV, the maximum attention was attracted 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 latest 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 motion pictures (this is probably why slow motion 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 as compared to others. This is because 1080p contains a maximum number of pixels compared to other varieties, plus 1080 progressive scan lines which are considered better than interlaced.