Some TV makers have already introduced 8K TVs, while others will join the race later this year. But there are lots of reasons why you shouldn’t buy an 8K TV this year. Allow us to explain.
A history lesson
Do you remember HD Ready and Full HD? It was the hot new trend over a decade ago. Some TV makers were so eager to introduce HD TVs that they forgot to include a MPEG4 chip for HD video decoding.
Even if you were lucky enough to be blessed by this essential building block in your very expensive – and tiny – HD TV, the sad truth is that some of the early HD TVs were underpowered forcing them to internally downscale a 1080p signal to lower resolution for video processing before upscaling it again to have it show in full-screen on the display panel.
Everyone had seemingly forgotten to tell distributors and content makers that HD was the new hot trend. It would take years before most broadcasters introduced 720p and 1080i HD channels, and even today there are almost no 1080p channels in most regions of the world. That is because broadcast standards were rushed through (without 1080p support) to accommodate those 1st and 2nd generation HD TVs.
Do you remember 4K Ultra HD? It was the hot new trend back in 2012. Some TV makers were so eager to introduce 4K TVs that they forgot to include HDMI 2.0 ports to make possible 4K input and forgot to include HEVC and VP9 chips for 4K video decoding.
Even if you were lucky enough to be blessed by one of these essential building blocks in your very expensive – and still relatively small – 4K TV, the sad truth is that some buyers never had a chance to watch true 4K video on their first 4K TV. Some manufacturers were promising upgrade kits for HDMI 2.0 or HEVC decoding but not everyone delivered, while others were slapping ridiculous price tags on their upgrade kits.
Everyone had seemingly forgotten to tell distributors and content makers that 4K was the hot new trend. It would take years before distributors could offer a decent selection of 4K content. Luckily, the distribution standards were not rushed through in half-baked form this time around.
But there was a twist to the story. 4K TVs were not selling in high quantities so the industry scrambled to find something else. The answer was HDR (High Dynamic Range) or what some in the industry prefer to call “better pixels”. As we were approaching the limits of human vision, the benefits of “more pixels” on relatively small TVs became a case of diminishing returns. HDR was exactly what was needed to revitalize the TV industry. The most exciting part? HDR standards have been designed with plenty of headroom and as such we are in the early stages of the HDR revolution. Even companies with "XDR" monitors are far from fulfilling the goals for color and dynamic range of current HDR standards.
So, about those 8K TVs
So, have you heard about 8K Ultra HD? It is the hot new… Okay, you can see where we are going. But has the past taught TV makers a thing or two?
Sadly not. Allow us to explain why you shouldn’t buy an 8K TV in 2019.
There is almost no 8K content and it will take years before it is readily available to consumers. Sure, a few 8K showpieces may show up somewhere out there this year or next year but current 8K TVs will most likely not be able to receive it (more on that in a minute).
The first 4K TVs were launched in 2012, so we are 7 years into this cycle. There is a good selection of UHD Blu-ray titles and a more comprehensive selection of 4K movies and TV shows on streaming services. New console games are typically released in 4K but are often upscaled from resolution between HD and 4K. There are very few 4K channels.
We have seen 8K TVs from most leading manufacturers and have reviewed TVs from Samsung (Q900R) and Sony (Z9G/ZG9). We have been in the industry for almost two decades and have heard all the anecdotes of HD and 4K upscaling. With 8K, the story repeats itself. Based on our examination of the first 8K TVs there is nothing to gain from upscaling HD or 4K content.
Upscaling is required to get a full-screen picture but processes such as object-based video analysis coupled with a database of reference pictures is mostly an exercise in applying picture enhancement and artificial sharpness. You don't need an 8K TV for that. Some may be surprised to learn that Sony has used object-based analysis coupled with a reference database throughout most of the 4K era. What's new is that some are marketing it as "AI" - artificial intelligence.
The sad reality is that once again certain TV makers have been so eager to introduce 8K TVs that they have forgotten to include HDMI 2.1 ports to make possible 8K input. It is true that HDMI 2.0 can transfer 8K at 24fps (such as Hollywood movies) but without HDMI 2.1 you will be out of luck when it comes to most other types of 8K sources, including PCs, game consoles, streaming players and set-top boxes.
Those 8K TVs that are equipped with HDMI 2.1 have only one HDMI 2.1 port. The remaining ports are HDMI 2.0. The exception is LG's Z9 that will be available later this year.
Streaming services are once again some of the first to offer 8K content. YouTube already supports it. Unfortunately, none of the existing or announced 8K TVs can receive and decode the streams. We have asked all manufacturers who have announced plans to launch 8K TVs this year, and the answer is always that YouTube's 8K is not supported. YouTube's streams will be capped to 4K. With these TVs, the same will most likely apply to Netflix and other streaming services who introduce 8K in the future.
While the HEVC format can, on paper, handle 8K video (a TV must support HEVC profile 6.1 or higher to decode 8K compressed in HEVC), it is not optimized for 8K. Everyone that we have spoken to in the distribution chain agree that a new video codec is required to make 8K streaming possible at scale and economically viable. New codecs from the Alliance for Open Media (Amazon, Apple, Google, Netflix etc.) and other standards bodies are currently in development but the hardware solutions are not ready yet, and as a consequence decoder chips are not integrated in current 8K TVs – and cannot be added via software.
More pixels, better pixels
We saw 8K in action for the first time almost a decade ago. We have witnessed more demos than we can remember. Most of it is beautiful. Timelapses, stills of flowers or human faces, slow-panning shots of landscapes etc. There is a common theme here, which is lack of movement. That is because 8K video requires a far higher frame rate to maintain 8K resolution even at slow-to-medium paced motion.
We recently had a chance to see a “top-secret” clip from a remastered version of a movie from one of Hollywood’s most respected directors. We can't reveal the title (it wasn't 2001: A Space Odyssey) but it was obviously shot in 24fps - like basically everything else from Hollywood. It was an action sequence and whenever there was movement, it would degrade to look like something shot in HD resolution or below. The same is true for 4K video but the content industry continues to ignore it so why would we expect better results with 8K?
There is another twist when talking about movies. For 4K there is a huge back catalog of movies shot on 35mm film that can be rescanned and remastered to 4K or perhaps slightly higher resolution, although with limitations. For 8K you need 65mm film or a modern digital 8K camera for optimal results. There are far fewer examples of movies shot on 65mm film.
That’s movies. There’s also gaming, live sports etc. The point remains. 8K necessitates higher frame rate. Instead of talking about more pixels, we should be talking about better pixels. High Dynamic Range (HDR), High Frame Rate (HFR), wider color gamut. We have seen all of the leading manufacturers’ 8K TVs - and even some prototypes - and we would still pick a great 4K HDR over an 8K TV any day.
We should also point out that the first 8K LCD TVs have excessive power consumption. A 75" Samsung 8K TV averages over 400W and peaks at close to 500W in some scenes. A 85" Sony 8K TV averages over 500W and peaks at over 800W in some scenes. The latter has earned a 'G', the lowest level, on the energy label scale. Part of this can be explained by manufacturers' desire to reach higher peak brightness levels but it is also directly related to 8K resolution because more pixels lead to a larger percentage of the screen area being "dead space" between pixels. More light is wasted in generating the picture.
Some of the first 8K TVs cannot render full 8K resolution. That's because they take from resolution to improve viewing angles by employing so-called sub-pixel rendering. Depending on the scene and picture composition, some pixels are turned off or dimmed down to create more space between active pixels, which can in turn expand viewing angles as it minimizes light pollution between active pixels.
This effect is illustrated in the two pictures on the right. Notice how shadows and areas around the hairline pixellate. Here, the effective resolution is lower than 8K. In the other example, you can see how it works. Pixels are controlled in clusters of four. With this shade of green, only one pixel is lit, while the three other pixels are either dimmed down or turned off. In the worst case scenario, you get 4K resolution but this will require special test patterns. With real content, you are more likely to see effective resolution somewhere between 4K and 8K.
The challenge is that narrow viewing angles will prove more problematic as the industry transitions to 8K because TVs tend to get bigger and viewers tend to move closer. As a result, narrow viewing angles will not only affect viewers watching the screen off-axis but also the viewer directly in front of the screen who may notice how corners and edges lack saturation or contrast.
These photos were shot on Samsung's Q900R 8K LCD but the same technology, 'Q Ultra Wide Angle', is used in the company's more recent 4K and 8K TVs.
New tech hates 8K
HDMI VRR (variable refresh rate) and possibly other new technologies refuse to collaborate with 1st and 2nd generation 8K TVs. The first 8K TV with VRR (LG Z9) will not support VRR at 8K resolution - only 4K. Over time, we are fear that limitations in other areas will come to light. For what it is worth, Sony says that its Z9G/ZG9 will support Dolby Vision at 8K but the real question is: at what frame rates? The first 4K TVs with Dolby Vision were limited to Dolby Vision playback in 4K30 (30 frames per second).
Those were some of the relevant technical factors that you should consider before buying an 8K TV. There are of course other factors such as price but the technical challenges must be overcome before anyone can claim that 8K TVs are ready.