High-calibre cinema films such as “Avengers: Endgame” or impressive documentaries are shot with special video cameras, some of which can reproduce resolutions of 8K Ultra HD. The technological path that lead to these advancements was long and hard. We provide you with an overview of the milestones in video resolution.
It’s not always black and white
Since the introduction of the talkies in the 1930s, cinema and television films have become very popular. Black and white television was soon replaced by analogue color television by the 1960ies.
The so-called Digital television transition, the conversion of television to digital, has been underway for years and has almost been completed. Technologies and innovations have almost overturned and this is still the case today.
Screen resolutions: Standard definition
In retrospect, analogue television is now being referred to as Standard or Low Definition Television, SDTV or LDTV for short. The formats that were used for color transmission at that time may still be familiar to some readers: PAL in Europe and NTSC in the USA.
In this context, the SECAM format, which was used in other parts of the world, for example in Russia or parts of Africa, should also be mentioned. The image resolution of these three formats is almost a joke compared to today: 720 x 480 (and 720 x 576) pixels. This results in a total of 345,600 pixels on the screen. 8K Ultra HD is light years ahead of this.
Screen resolutions: High Definition
But even then the television industry was by no means at a standstill: High Definition Television formats, including HDTV, were quickly on the rise. In 2005, “HD ready”, better known as 720p, was in the starting blocks. Here the resolution was 960 x 720 pixels with a 4:3 ratio – a step forward. Widescreens even had 1,280 x 720 pixels.
Although it is the smallest format in this class, it still belongs to HDTV. Today, hardly any screens are produced in this resolution, as they have simply become obsolete over time. We have simply left this resolution behind us.
The next higher resolution is Full HD 1080p. To give a comparison: In contrast to 480p SD, Full HD 1080p has four times the pixel density. This is now standard in the broadcasting sector, although there are still some stations that transmit their content in SD. The public broadcasters and some third parties broadcast free of charge in HD.
Private broadcasters charge an additional fee for HD programs. The current and previous generation of gaming consoles also make video games possible in Full HD or higher. Though in all these industries a clear change is noticeable.
State of the Art: 4K Ultra HD and 3D
Already in 2012, the Consumer Electronics Association announced the upcoming standard and successor of Full HD: 4K Ultra HD. In the cinema, this corresponds to a resolution of 4,096 x 2,160 pixels with an aspect ratio of 19:10. The term 4K can be traced back to the 4,096, by the way. This corresponds to four times the resolution of Full HD.
At home it looks a bit different: The majority of domestic televisions have an aspect ratio of 16:9. Therefore, sets that are sold as 4K televisions are not “real” 4K sets, although they are advertised as such.
The corresponding resolution in the 16:9 ratio is 3,840 x 1,620 pixels, referred to as UHD-1. (More on UHD-2 will follow later.) At this point it should be mentioned that the terms 4K and Ultra HD are commonly used synonymously. However, the difference between these two resolutions is hardly noticeable to the eye of a layman at first glance.
Streaming in 4K?
Yet, UHD-1 is not as widespread in homes as Full HD still is – but it is quickly gaining popularity. The dominance of Full HD is not only due to the price of UHD TVs, but also to the fact that content in Ultra HD content is still somewhat rare.
Some video games, blu ray discs and streaming providers are already experimenting with UHD-1. Still, technical requirements for streaming in UHD are high, especially in the consumer sector. For the transmission of content in this resolution, a DSL connection of at least 25mbit/s is an absolute must.
Long live 3D!
Another innovation of recent years is 3D technology. With the help of 3D-capable televisions and appropriate glasses, it is possible to create spatial depth. Here, video signals are displayed separately for the left and right eye. However, this technology has never really established itself in the home sector, however, 3D is much more popular in the cinema.
Ultra HD: Visions of the future for Cinema & Co.
4K is more at home in the cinema – also in the aforementioned 19:10 format. Not least since the discontinuation of analogue film cameras, the cinema industry has experienced an extreme turnaround.
The use of 6K or even 8K cameras consumes a considerable amount of storage space. The exact amount depends on the format, frame rate, color depth and other factors, however, it can not be determined spot on.
Some films are produced in even higher resolution: UHD-2 or 8K. UHD-2 corresponds to 7,680 x 4,320 and 8K has 8,192 x 4,320 pixels.
The Japanese broadcaster NHK has been testing this image format for some time. With an aspect ratio of 16:9 this corresponds to sixteen times (!) the resolution of Full HD with 120 full frames per second. Considering we have had the first LCD and Plasma screens twenty odd years ago, this a an incredible achievement.
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The use of this format is rare, not least because of the technical requirements: The minimum transmission rate is 24 Gbps. In addition, 8K-capable devices are extremely expensive (fully equipped cameras are in the six-figure range) and the number of available media is small at this time.
Here lies the question whether 8K is necessary at all. According to research, the human eye can hardly tell the difference between Full HD and 4K. Do we need 8K at all? The display technology industry will probably continue to work on resolution, but other features are just as expandable.
Where does the future of TV lead?
The keywords color space, contrast range, luminance and HDR play a role here. All these have nothing in common with resolution. As already mentioned, the difference between 4K and 8K will hardly play a role for the end user, but color depth and richness of contrast are much more noticeable to the human eye.
LG’s OLED and Samsung’s QLED are two technologies that are driving this development to make colors more lifelike and richer in contrast. Resolution is not everything. Which some manufacturers won’t be deterred from, because yes—there are already screens and cameras for 16K.
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