Resolutions explained

Display technology is advancing at quite a pace. 4K has become the standard in consumer displays. But is 8K just a gimmick? Amy Wallington attempts to untangle the complex subject that is resolutions.

Display resolutions have come a long way over the years. Advances in technology have maintained steady evolution and means we are now spoilt for choice when it comes to displays for our homes. But now, displays have developed so much that it’s often confusing knowing what is best for your client’s home. We have barely got a grapple on 4K yet, with very little content being produced, and yet we are already seeing 8K-ready devices and even talk of 16K!

Resolution is all about the pixels, so the higher the resolution, the more clarity and colour you get from the picture. Pixels are arranged in lines and the number of lines define what the resolution is. But it’s not that simple. There is often a lowercase ‘i’ or ‘p’ that refers to how the lines are loaded which also affects the image quality. The ‘i’ stands for interlaced, meaning that every other line of pixels is refreshed with each new frame, whereas ‘p’, which stands for progressive, means that all the lines of the frame are loaded simultaneously, resulting in a better quality picture especially for high-action scenes.

We started out with Standard Definition, or SD for short. According to Michael Price, brand development specialist for Panasonic UK, SD was more of an umbrella term for various resolutions. “SD varied a lot in resolution because TV broadcasts used to be delivered as an analogue signal,” he explains. “For example, when BBC2 started in the 1960s, it was higher resolution than BBC1. The digital definition of SD is 640x480 (with 480 being the number of horizontal lines), but most TV broadcasts in the UK were 575 lines before the digital switch over.”

In the late 1990s, 16:9 widescreen SD was introduced. This didn’t actually increase resolution but only stretched the image. As we entered a new century, HD came along, and the huge TVs with a boxful of electronics on the back of them were swapped for a slick flatscreen. Christopher Mullins, home cinema product manager for Sony Professional Solutions Europe, recalled: “It wasn’t until the 2000s that HD was introduced, alongside flat panel TV technology that offered a lot more resolution and in true 16:9 with 1920x1080 resulting in square pixels. It came in an interlace format typically used for broadcasts and a progressive format which was used for Blu-ray production primarily. This was a big step up in image quality over SD with around five times the number of pixels.”

To avoid streaming movies, Kaleidescape customers download their 4K content

4K vs 8K
TV manufacturers have continued innovating and fitting more pixels into displays, and in more recent years, we have seen the development of Ultra High Definition (UHD) 4K and 8K. As James Thomas, product manager, home entertainment, LG UK, says: “4K is the resolution standard amongst televisions now. However, 8K is a higher resolution that quadruples the total number of pixels, similar to how 4K did with 1080p. 

“1080p is around 2,000 horizontal pixels at 1920x1080 and 4K is approximately 4,000 horizontal pixels at 3840x2160. That means that there are twice as many pixels both horizontally and vertically. Furthermore, this means that each step amounts to quadrupling the number of pixels, meaning that 8K has 16 times the number of pixels as 1080p.”

The development of 4K did not just improve the resolution but it also set the stage for other improvements. Mullins explains: “The UHD standard not only targeted an improvement in resolution but also put in place a roadmap to improve colour, with much wider Rec2020 colour space, and dynamic range, with the High Dynamic Range standards. This resulted in another leap in detail with four times the pixels but also with much better individual pixels creating a more realistic image than ever before.”

"To see 8K resolution pixels, you would have to sit just over five feet away from that screen."

He adds: “Having more resolution enables larger displays to have higher pixel densities so that viewers can sit closer and have an even more immersive experience without seeing the pixel structure. 8K only makes sense on larger displays such as 70-in+ as 4K on smaller display devices has sufficient pixel densities for typical viewing distances.”

It’s all well and good that display resolutions are improving but content creators also need to follow this trend and create the content to match it. At the moment, TV manufacturers are moving much quicker than the content creators in terms of 4K, 8K and even 16K. UHD 4K was launched almost 10 years ago, and yet we are only just starting to see 4K content becoming more mainstream. 

“Most of the major ways we enjoy TV now have a 4K option: Sky Q has 4K movies and sport, as do Virgin and BT boxes,” states Price. “Netflix, Amazon, Apple TV, Rakuten, and many other streaming services have plenty of 4K shows and movies. Video sharing sites like YouTube and Vimeo have lots of 4K. Blu-ray has gone 4K, with hundreds of titles available on disc. 4K gaming is part of PlayStation, Xbox, and PC gaming. People can even record their own 4K on their phones.

“However, the regular, free-to-air TV channels are not in 4K – Freeview only has around 16 channels in HD, never mind UHD. But that is starting to change. BBC iPlayer has some limited content in 4K HDR, like David Attenborough’s documentaries, and it also broadcast every football match of the most recent World Cup in 4K.”

Spot the difference 
Consumers are excited by the rising numbers in resolution and are rushing out to buy the latest and greatest TV for their home. But can the human eye even tell the difference between 4K and 8K? Is 8K and beyond a waste of money for consumers? This is a big question and there are many factors that it depends on. 

It doesn’t just make the picture better quality, there is real science and maths behind it. This is where it gets very technical as an integrator building something such as a home cinema. When choosing between a 4K and 8K display for your client, equations need to be drawn up to calculate the viewing distance and screen size to decide whether our eyes will even notice the difference.

“More resolution is great, but perception of resolution depends on how big the screen is and how close you sit,” confirms Price. “In my experience, the extra detail in an 8K screen only really becomes noticeable on an 85-in or bigger. Whilst it is true that the average TV screen is getting larger, I think 85-in screens will always be fairly specialist.”

Cheena Srinivasan, founder and CEO of Kaleidescape talks about the distance required between the screen and the viewer in order to notice a difference. “The human eye can resolve pixel-level detail in a 4K image from three picture heights away. For an 85-in TV, that is 10.5 feet. To see 8K resolution pixels, you would have to sit just over five feet away from that screen.” 

LG's OLED screens have self-emitting pixels which deliver an infinite contrast ratio thanks to its ability to achieve perfect blacks, accurate and rich colours and precise detail in imagery

As mentioned earlier, TV manufacturers are a lot further ahead with development than content providers are. Consumers are being encouraged to buy the latest and greatest TV with the best resolution, yet there is not a lot of content to watch in that specific resolution. 

“There is always a chicken and egg scenario in the early days of a new image standard, and this was seen with 4K,” Mullins points out. “Content creators don’t want to create content without a sufficient proportion of displays supporting it. TV manufacturers quickly supported the standard and as overall proportion of compatible devices grew, more and more content became available. 

“Nowadays, there has never been a better time to own a UHD HDR TV or projector. Streaming services are offering hundreds of hours of UHD content and OTT services streaming live sports in UHD. On the physical media side, UHD Blu-rays are now being produced in the highest available video and audio quality for all new releases and remasters of classic films. Also, gaming consoles like the PS4Pro supports 4K HDR gaming, so you can enjoy your latest games in the highest fidelity.”

"In my experience, the extra detail in an 8K screen only really becomes noticeable on an 85-in or bigger."

Price adds: “Blu-ray can cope with 4K resolution and in fact, is the highest quality version of 4K. To give an example, Netflix recommends 20Mbps internet speed for its 4K content. However, Blu-ray is capable of up to 100Mbps transfers. Blu-ray also tends to carry the most advanced versions of HDR.”

But we are beginning to lose physical media as consumers turn towards on demand content through streaming services and downloads. Thomas says: “With the evolution of resolutions, DVDs and Blu-rays are becoming a thing of the past. DVDs are unable to store as high a pixel resolution as TVs cater for, meaning that for many consumers, viewing films online is much easier and more efficient.”

Movie studios have begun to offer the vast majority of new releases in 4K resolutions over the last few years, so the content is available. Thomas adds: “8K content is already available, but it isn’t mainstream yet. It is a new and exciting innovation, but at the moment, 8K content is sparse and requires a huge amount of bandwidth. As such, the underlying technology, or infrastructure, needs to improve first before 8K becomes widely available.” 

Kaleidescape is designed to provide the high end experience, so instead of streaming to flat panels and smartphones, the movies are downloaded by the viewer for a full home cinema experience. 

Srinivasan explains: “Our 4K content is downloaded over the internet to our customers’ Kaleidescape systems, so for residential customers, an internet connection is essential. Delivering 4K content is similar to delivering movies in any other resolution, except the file sizes are bigger to account for more digital video information.

11 TX-65GZ2000 (Lifestyle) (1)
Panasonic’s OLED Lifestyle TVs control the light right down to the level of every dot (8.3 million on 4K TV)

“With our Marine Movie Service, yacht customers no longer need an internet connection to receive their content. After making a selection online, their movies are factory-loaded onto an encrypted hard drive and delivered to them.”

As Thomas said, delivering this type of content requires a lot of bandwidth. However, Kaleidescape have found a solution around this. “Because our content is downloaded and not streamed, bandwidth is never an issue during playback,” continues Srinivasan. “Our customers are able to truly enjoy their movie-watching experience without the drawbacks of streaming – no buffering or pixilation due to high levels of compression.

“Our movie downloads are large, but most of our residential customers have fast internet connections so this is rarely an issue. In the past, our yacht customers have occasionally had issues with bandwidth, but this has been resolved with our Marine Movie Service.”

Package deal
Resolutions is just one part of a home cinema experience. As we perhaps reach the best picture we are ever going to be able to see with the naked eye, the focus is now turning to audio to create a unique, immersive, whole-cinema experience in the home.