4K Ultra HD: in the world of high definition

It's hard for a modern user to believe, but at the dawn of the era of television, the resulting image consisted of only 25 vertical lines. For the first time, the term "high definition" came to the world of television already in the 30s, when black-and-white systems capable of providing more than 200 lines appeared. By the end of the 60s, NTSC (480 lines) and PAL (576 lines) colour systems were ubiquitous — such televisions were still popular in the early 90s, many readers should remember them.

But they really started talking about high-definition television only by the end of the last century, when liquid crystal and plasma televisions began to appear en masse. Today it is difficult to surprise anyone with a TV with a resolution of HD (1280x720) or Full HD (1920×1080). It would seem that perfection has been achieved. But it was not there.

The birth of Ultra-high resolution 4K Ultra HD

At the beginning of the century, televisions with large diagonals were a novelty. Quite common today, 40-inch models then seemed like real monsters, while in the world of computers, 17-inch monitors were the most common.

But as time went on, the diagonals increased not only for televisions, but also for smartphones. And the larger the diagonal of the screen, the larger each individual pixel turns out to be, and at the same time the whole image becomes grainy. And if the Full HD resolution looks excellent on the 36-inch model, then with more impressive diagonals it loses a fair share of its clarity. On the market already appeared 65- inch TVs, which will turn the room into a real home theater. Full HD is definitely not enough for such a "canvas".

Illustrative example: comparison of high (480p), high (1080p) and ultra-high definition (UHD) standards

For the first time, work on ultra-high definition standards began back in 1994, the first transmission was carried out in 2003, and an optical cable was used for this. Already in 2012, the Rec.2020 standard itself was introduced, which describes the parameters of televisions with this resolution. A year later, the first satellite broadcast took place, at the same time mass production began Ultra HD TVs that any user can buy today.

What are the advantages of Ultra HD in comparison with Full HD

During the Wimbledon tournament in 2013, Sony presented an unusual advertisement: the company's logo was applied to the nails of tennis players. Thus, the Japanese manufacturer wanted to emphasize the capabilities of its new Sony Bravia X9 TVs with 4K Ultra HD resolution — the image provided by them is so clear that even such small inscriptions are perfectly distinguishable.

Diagram of the colour space of Ultra HD standards, (outer triangle) and Full HD (inner triangle)

Simply put, a four in the term 4K Ultra HD (aka Quad HD) means that the new resolution is, as it were, composed of four Full HD and is 3840x2160 pixels. Thus, the number of pixels on the screen increases from two million at once to eight.

The matter was not limited to one multiplication of the available resolution, since in fact such an “innovation” would not have given a noticeable increase in quality. The Rec.2020 standard implies other "goodies":

• the progressive scan frequency can reach 120 frames/sec;
• the colour depth is 10/12 bits, which allows you to display a huge number of shades;
• expanded support for multi-channel audio, which can now be 24 audio channels at once.

For comparison, it is appropriate to describe the Rec.709 standard, which is the basis of HDTV: resolution up to 1920x1080 pixels (Full HD), progressive scan of 60 Hz, colour depth of 8 bits. The difference is obvious.

What is interesting: it was not limited to 4K alone, and already today the 8K Ultra HD format (aka Super Hi-Vision) is presented, the resolution of which reaches a fantastic 7680 × 4320 pixels. However, there is no talk of mass implementation yet. The time of 8K will come, but this should not be expected earlier than in 10-20 years.

It should be noted that many similar resolutions with about 4000 pixels horizontally fall under the concept of 4K and 8K. However, when it comes to televisions, it means 3840x2160 and 7680×4320 pixels.

Disadvantages of 4K Ultra HD TVs

TVs with 4K Ultra HD resolution support already they have appeared on the market, but there is an acute shortage of content for them. So far, you will not find full-length films, everything is limited only to short videos. Manufacturers can talk for as long as they want about the advantages of ultra-high resolutions, but there is nothing special to look at them. But content is a lucrative business, all modern films are already shot with 4K Ultra HD resolution, and one of the most popular video hosting companies in the world, YouTube, has already added the ability to download and watch videos in this resolution.

Together with the increase in the diagonal of the TV screen the size of each individual pixel increases

The problem with the media has not been solved, because there is no corresponding standard for Blu-Ray discs. And although there are BD players on the market with the label 4K Ready, but in fact they are engaged in stretching the usual Full HD image to the screen with a new resolution. This is done in a fairly simple way: each pixel of the image occupies 4 pixels on the screen. The result is quite good, but still far from what the Ultra HD world actually has to offer.

We haven't fully decided on compression standards either, since the capabilities of H.264/AVC are clearly not enough anymore. Most likely, it will be replaced by a more advanced HEVC/H standard.265.

Today it is possible to provide 4K resolution transmission with a frequency of 60 Hz only using the DisplayPort interface. In the case of using the standard HDMI 1.4b transmission is possible only at a frequency of 30 Hz, which is no longer enough for active 3D. The HDMI 2.0 standard should correct this situation (which will also support 32 audio channels), but there is no talk of its mass implementation yet.

Hp at the same time, the world is moving towards 4K Ultra HD. Having presented the latest model in 2013 Mac Pro, Apple emphasized that its capabilities are sufficient for processing 4K video in real time. The support of the format is reported by the creators of game consoles PlayStation 4 and Xbox One, but it's only about playing videos.

Gradually becoming widespread amateur video cameras capable of shooting video with such resolution. As for photos, even an ordinary iPhone will easily provide the appropriate images, since 4K is 8 megapixels.

The most affordable 4K Ultra HD TV

The honor of releasing the first available model belongs to the Chinese manufacturer SEIKI Digital. We are talking about the SE39UY04 39-inch model introduced in 2013, the recommended cost of which was $ 700 (at the time of writing, it had already dropped to $ 450). More recently, it was an acceptable price for models with Full HD resolution.

And here we come to a very important point. The fact is that in fact the model does not quite meet the Rec.2020 standard. The 4K Ultra HD resolution TV supports only at a frequency of 30 Hz, and the 120 Hz claimed by the manufacturer work exclusively at Full HD. In other words, in front of us is actually an ordinary TV, which is simply equipped with a new matrix. The model described above is used only as an example. Many other manufacturers indicate the maximum supported resolution and frequency values in the specifications – pay special attention to this point if you are going to buy a 4K TV.

Philips 42PUS7809 is one of the available TVs with Ultra HD resolution support

The fact remains: the beginning of the mass distribution of the Ultra HD standard has been laid. It will take less than a decade and we ourselves will not notice how we will be surrounded everywhere by screens with 4K resolution. Experts predict that by 2017 the supply of these TVs will be 3-5% of the total.

But at the moment, TVs with 4K Ultra HD resolution are noticeably ahead of their time. And this means that your existing Full HD TV can still serve faithfully for several years until the market learns to fully use the full potential of the new format.

It's a completely different matter if you want to purchase new TV with a screen size of more than 40". In this case, it makes sense to look at the models with 4K resolution to get a device "with a margin".