Mis à jour le 26 February 2019.
Is 2017 set to be the year of Ultra HD Premium? Now that TV manufacturers dedicate most of their production to 4K UHD screens, the UHD Alliance has issued a new quality label in order to help consumers differentiate a good 4K UHD TV from an excellent one. Ultra HD Premium TVs are capable of displaying an even more contrasted picture (HDR technology), with an extended color gamut covering 90% of the natural spectrum while staying within a reference color space (BT.2020).
The HDR (High Dynamic Range) imaging used for Ultra HD Premium ensures a superior level of detail in both dark and light zones. OLED televisions are equipped with diodes capable of displaying an absolute black, giving them a major advantage over LED-backlit screens, which can only display dark gray at best.
In order not to penalize brands which do not use OLED technology, the UHD Alliance has decided to certify LED-backlit televisions offering a black level of 0.05 nits (or candela), with the added condition that their white level reaches 1000 nits. In other words, screens with a contrast level of 20,000:1.
By comparison, the contrast of Ultra HD Premium certified OLED TVs goes beyond 1,000,000:1, which is 50 times superior to LED TVs.
It is important to note that Sony manufactures screens which meet the requirements for Ultra HD Premium certification, but has decided to not label their products.
Ultra HD Premium certified televisions can display up to 8 million pixels and billions of colors, all while offering exceptional contrast. Yet, there aren’t many TV programs, films or series currently available in the Ultra HD Premium format. Only a few movies on Ultra HD Blu-ray discs meet all the requirements for Ultra HD Premium certification (4K/HDR/color space).
- As far as HDR is concerned, few movies are shot with compatible cameras. Yet, Star Trek Beyond (2016), as well as the two previous installments directed by J.J. Abrams, are all available in Dolby Vision Ultra HD HDR Blu-ray format.
- Ultra HD Blu-ray is compatible with the extended color space.
- On the other hand, it is a different story for 4K resolution…
If we were to compare image and sound, we could say that cinema uses FLAC files while UHD Blu-ray discs are in MP3 format. Although it may seem excessive, it is a rather accurate comparison. The new Ultra HD HEVC codec combines damaged, compressed images with others created based on those which come before and after. Color sampling is therefore very incomplete. Movies screened in cinemas work the other way around: each image is in JPEG2000 format, which applies non-damaging compression and uses optimum color sampling. This is why the picture on the big screen, although in 2K format (2048 x 1080p), is splendid.
Films in movie theaters are in 2K format and films on Blu-ray discs are in 4K UHD’ how is this possible?
The vast majority of films are mastered in 2K format for movie theater release because most cinemas use this standard. The cameras used to film are often 2K to 5K cameras and the mastering is done in the lowest resolution. Moreover, most special effects studios are only equipped with 2K technology due to the cost of Ultra HD.
As a result, most movies released in 2016 and available on Ultra HD Blu-ray discs were actually shot in 2K and upscaled to 4K format.
Yet, this is not the case for every single movie. The Revenant, for example, was shot and mastered in 4K. It has also been announced that the upcoming Avatar sequel will be shot in 8K, which will greatly boost the popularity of the Ultra HD Premium format. Another notable exception is animated movies. Mastered in 2K format, they can be upscaled to 4K thanks to the use of vectorial images. Without a doubt, the Blu-ray version of The Secret Life of Pets, set for a December release, will be splendid.
You may have doubts about it after reading our previous comments, but this would be a mistake. First and foremost, a 4K Ultra HD television offers a much better experience than a Full HD screen, even with 1080p, 1080i (DTV) or 720p content. The increased amount of pixels (8 million instead of 2 million) makes the image smoother and more precise. Moreover, images are also a lot more nuanced due to the high contrast capabilities of Ultra HD Premium TVs, an important feature given the fact that color nuance is what gives the impression of enhanced definition.
Ultra HD Premium 4K content also exists outside of movie theaters, thanks to NetFlix and Amazon.
Production technologies used for films and TV series are evolving at an incredibly fast pace. Netflix produces its own movies and TV series in 4K HDR, therefore adding content to the Ultra HD Premium offer. The Daredevil series, for example, is shot in 4K/5K, mastered in 4K and streamed in 4K. Amazon’s fantastic show, Transparent, is also shot, mastered and streamed in 4K. Most of the new series offered by these two streaming platforms are guaranteed 100% Ultra HD.
Previously released movies in Ultra HD Premium?
The Lord of the Rings, the second Star Wars trilogy, Avatar, and all the other iconic movies of the digital era are prisoners of the technologies they inaugurated. Filmed and produced in 2K, they will probably never be available in 4K format (maybe with a questionable 4K upscaling). The cost of a new production would be extraordinary since every special effect would have to be redone. On the other hand, telecine transfer to 4K format is possible for movies shot on film. In other words, it is possible to digitize the negatives to obtain a 4K HDR picture with an extended color space. A little patience is in order as some masterpieces are not yet available in 1080p Blu-ray format. The rumor has been going around that Disney has been working on Ultra HD 4K versions of all their animated films for a Christmas release.
Is there are future for optical discs?
DVD, Blu-ray and Blu-ray UHD discs are currently facing an uncertain future. Compared to their direct competition, VOD/streaming platforms, they are expensive and do not guarantee the best possible quality. Nevertheless, it is important to note that streaming a movie in 4K format requires a very high-speed internet connection, ideally cable or fiber. Optical fiber, or even future 5G technologies and above, will most certainly be the main way to enjoy Ultra HD Premium content. All we need now is a little patience.