8K TV technology explained: What is 8K and is it worth buying an 8K TV yet?

Despite that fact that many consumers have yet to make the jump 4K – and not to mention that native 8K content is sorely lacking – the likes of Samsung and LG are still plugging away with their respective 8K TV releases.

LG was the first to take the covers off of its 2020 8K TV range ahead of CES 2020, and Samsung has now followed suit with the grand unveiling of its fresh 2020 QLED 8K TV lineup.

Although 8K is still an edge technology from a consumer viewpoint, it’s not new. Sharp became the first manufacturer to unveil an 8K TV all the way back in 2013, at that year’s CES, and Panasonic, Sony, LG, Samsung and Hisense (among others) have all since joined the party.

It was only recently that many of these manufacturers committed fully to the tech. At CES 2019, Samsung went hard on 8K with the launch of four models in its Q900 range, but the Korean giant was criticised – mostly by its rivals – for not delivering what LG calls “real 8K”. So, at the start of January, the Consumer Technology Association (CTA) released the official 8K standard which should help clear up this spat.

Below we’ve explained more about 8K TV technology, how it compares to 4K and whether it’s worth shelling out the eye-watering prices for the tecchnology just yet.

8K TV technology

To explain 8K TV technology, we need to look at it in context.

What is 8K and how does it differ from 4K?

From Full HD to 8K, advances in TV technology are largely represented by an increase in the number of pixels. Of course, this is simplifying things somewhat but it’s a good place to start.

• Full HD (FHD) TVs have a resolution of 1,920 x 1,080 – a total of 2,073,600 pixels
• Ultra HD (UHD) TVs push this resolution to 3,840 x 2,160 – 8,294,400 pixels
• UHD is often referred to as 4K, but 4K is technically a cinema standard and a true 4K resolution is 4,096 x 2,160 pixels – 8,847,360 pixels
• 8K TVs need to have a resolution of 7,680 x 4,320 pixels to meet the official 8K standard, which equates to a total of 33,177,600 pixels

Put simply, Ultra HD TVs have four times the resolution of standard Full HD TVs and 8K TVs boost this resolution a further four-fold meaning 8K resolution is 16 times sharper than HDTV. You can read more about Ultra HD and 4K explained here.

However, it’s not quite as straightforward as this.

The 8K TV technology standard

In an attempt to reduce confusion and help consumers make more informed choices, the CTA is responsible for setting the official standard for TV technologies.

In September last year, the CTA announced the official industry display definition and logo (see below) for 8K Ultra High-Definition (UHD) televisions and this standard came into effect on 1 January 2020.

As was the case when the CTA defined the 4K standard, the 8K Ultra HD definition was drafted in collaboration with manufacturers and, among the industry definition’s attributes are:

• For a TV to bear the 8K UHD logo, it must have a display resolution of at least 33 million active pixels, with at least 7680 horizontally and 4320 vertically when viewed on a 16:9 screen
• CTA states that 8K TVs should “meet a minimum of 50% contrast modulation using a 1×1 grill pattern“, as defined by the International Committee for Display Metrology (ICDM)
• One or more HDMI inputs must support this resolution of 7,680 x 4,320 pixels as well as support bit depth of 10-bits and frame rates of 24, 30 and 60 frames per second
• The 8K TV technology must be capable of upscaling SD, HD and 4K video and display it at the agreed 8K UHD display resolution
• It must also have the capability to receive 10-bit 8K images and render an image that “shows responsiveness to changes to any of the 10 bits”

The full 8K UHD TV standard is detailed here.

Further to this official standard, Hisense, Panasonic, Samsung and 13 other members recently formed the 8K Association (8KA) at CES 2019. This association sets 8K TV specifications as:

• Resolution: 7680 x 4320 pixels
• Input Frame Rate: 24p, 30p and 60p frames per second
• Display Luminance: More than 600 nits peak Luminance
• Codec: HEVC
• Interface: HDMI 2.1

Why were Samsung’s TVs classed as “fake 8K”by rivals?

The first wave of 8K TVs, including those from Samsung, don’t technically render a full 8K resolution.

This is because they use what’s known as sub-pixel rendering in which some pixels are switched off or dimmed down to create more space between active pixels. This, in turn, boosts viewing angles by minimising light pollution between these pixels.

LG, in particular, has said Samsung’s use of sub-pixel rendering means it shouldn’t be allowed to use the term 8K to advertise its TVs. Specifically, it claims that despite Samsung’s 8K TVs meeting the minimum resolution, their contrast modulation isn’t high enough to meet the requirements.

Samsung hit back by saying that contrast modulation (CM) matters less than brightness, luminance and other processing technologies.

In a statement, Samsung said at the time: “CM is a concept introduced in 1927 and is not suitable for evaluation of colour displays with ultra-high resolutions.

“The International Committee for Display Metrology (ICDM) said in May 2016 that CM did not sit with the latest displays and a new evaluation method was needed.”

Samsung has since adjusted its 8K TV technology and its entire QLED 8K 2020 range – including the flagship Q950TS – meets the requirements for the 8KA and CTA Ultra HD certifications.

What is contrast modulation?

The International Committee for Display Metrology (ICDM) is responsible for setting the Information Display Measurements Standard (IDMS). IDMS has become the go-to guidelines for standard measurement practices for quantifying electronic display characteristics and qualities.

The IDMS covers various display measurements, including resolution and bit-depth, plus the contentious contrast modulation score.

Contrast modulation measures the ability of a display to distinguish a pattern of alternating white and black lines”. The higher the number, or percentage, of lines a display can show, the sharper and clearer images and text appear.

For text, and graphics, the edges must be shown in clear contrast to make them easy to read and anything higher than 50% is considered clear enough. The definition for images is lower, at 25%. LG’s TVs have scored around the 90% mark, whereas it claims its rivals barely reach 12%.

Should I buy an 8K TV yet?

Samsung’s top-end 8K TVs in 2019 launched with a staggering $30,000 price tag – no, we haven’t misplaced the comma there. A lower-end model sits around the $5,000 mark. All things considered, it’s not quite a question of should you buy an 8K TV, it’s whether you can afford to.

If you can, bear in mind that there is very little 8K content, and it will be years before such content is readily available to consumers. 4K is still in its relative infancy when it comes to content, although it grew significantly in 2019, and this is partly due to a vicious cycle of supply and demand.

It’s only really worth investing in an 8K-ready TV once there’s enough native 8K content available to watch on it. That time will come but it’s a ways off yet.