LG puts a new measurement on 8K

LG Australia showed its world-first 8K OLED TV (the 88Z9) at an ‘LG Movie Night’ at Circular Quay on Thursday evening. 

LG’s 8K OLED (above, and first image below) is certainly a great-looking TV in both its presentation of content and its external design. Its bench-style base is integral, and includes an 80W ‘blade’-style soundbar tucked under the top of the gap, with larger drivers for bass in the bottom section.

While the OLED panels (made by sister company LG.Display) provide a potential picture-quality advantage for the Korean company over its main rival Samsung in the 8K (and other) spaces, the company has also recently offered a second differentiator: the distinction of surpassing the resolution measurement criteria as set forth in the Information Display Measurements Standard (IDMS) established by the respected International Committee for Display Metrology (ICDM), “which says that the stated resolution of a display does not depend on merely meeting or exceeding a specific number of pixels, but also on whether those pixels can be adequately distinguished from one another in order to deliver the stated resolution”. 

LG points to the ICDM’s definition of Contrast Modulation (CM) to measure this ability to distinguish neighbouring pixels from each other, with the ICDM requiring a minimum CM value above 25% for images and 50% for text. This is entirely understandable -  if you can't easily distinguish one pixel from the next, it undermines the resolution itself.

“An 8K TV with a CM value lower than these required thresholds does not deliver real 8K, even though the TV may in fact have the sufficient number (7,680 x 4,320) of pixels”, claims LG. 

And if you've never heard of the IDMS or the ICDM, the latter's member companies include such imaging mainstays as DataColor and Gamma Scientific (and not, so far as we can see, LG itself). It also has a page of handy public domain test images here, although these currently top out at 4K.

The Consumer Technology Association's Video Division is saying that a display should only be referred to as '8K Ultra High Definition' or '8K UHD' -  use the related logo - if it hits a minimum 50% CM.

Needless to say, both LG’s Signature OLED 8K and its 8K NanoCell TVs pass the ICDM test, claiming CM values “in the 90% range”. 

To which the obvious question is - Do its rivals (i.e. Samsung) fail this test, or have they merely not been measured?

To which the answer was ‘yes’, the “competitor” has been measured and its TV's scores fall between 12% and 18%.

Is that simply the difference between OLED and LED-LCD technology? OLED would seem to be inherently more capable of achieving a high CM since it has individually illuminated pixels - of course a backlit LED-LCD couldn’t compete.

But apparently LED-LCD can compete, because LG’s Nano Cell 8K TV scores in the 90s as well, and that's also an LED-LCD. So what's going on?

The answer seems to be what Samsung calls its "uniform light-spread layer", saying on its website:"You don't have to sit directly in front of the TV anymore. A uniform light-spread layer helps you get our most optimal TV viewing experience, from virtually wherever you are in the room." 

This layer, designed to spread light in a wider arc, was added to improve the off-axis performance,, or how far to the side you can sit before the picture quality degrades significantly. Most likely this was added in a bid to compete with OLED's far wider viewing angle, another natural advantage of front illumination compared with rear. 

But it has the side-effect that this deliberate spreading of light affects the measurement of CM at adjacent pixel positions. 

It's not obvious whether this would reduce resolution at the viewing position, especially when single pixels are below the threshold of resolution in many 8K viewing scenarios. An alternate view might be that this is more a measuring artefact. Samsung has a different group to which it belongs, the '8K Association', which has a different set of requirements for 8K certification and use of its logo, and CM is not among those requirements. 

All of which leaves us as yet uncertain how much CM measurements are relevant to an assessment of picture quality.

But one comparison at the LG event was impressive.

When an LG 4K OLED was shown against an LG 8K Nano Cell LED-LCD, both playing the same real-world content, the 4K OLED was a clear winner.

So the display technology itself can trump resolution, at least until we have actual 8K content on tap. And that's a year or two away for anything much, let alone mainstream content.

An argument often levelled against OLEDs is that their lower nit levels make them less effective in conditions with ambient light, reducing their ability to portray (or rather for us to perceive) low-level blacks. To which LG's General Manager of Marketing Angus Jones notes that they were confident enough in their prize OLED that they've placed it for two days of full Sydney sunlight in a transparent dome in the middle of the forecourt outside Circular Quay's Museum of Contemporary Art. Where it looks very cool. Nice cauliflower snacks too.

“Today we’re thrilled to offer a product that delivers the ultimate home entertainment experience available in Australia," he told us. "The LG OLED 8K TV combines LG OLED display technology and 8K resolution for the best visual and true-to-life experience. On top of this, the TV will equip consumers for what’s to come with 8K content in the near future, such as the 8K gaming consoles expected in 2020.

“It’s more than just a TV with an increased number of pixels and perfect blacks, it also delivers all of the latest display technologies consumers would expect and want. The powerful Alpha 9 (α9) Gen 2 Processor uses Artificial Intelligence to upscale standard definition or 4K content for a realistic audio-visual experience, such as clear speech and skin tones. Meanwhile, compatible cinematic content can be amplified with Advanced HDR 10 with Technicolor, Dolby Vision and Dolby Atmos for an incredibly immersive setting.”

The new TV will be initially sold through selected Harvey Norman stores, with installation included in the Australian RRP, which for the 88-inch OLED 88Z9 is... $59,999. More info HERE.


Also released in Australia is LG’s 8K NanoCell TV (model 75SM9900PTA in Australia, above) in a 75-inch model, with ‘Nano Black’ (Full Array Local Dimming Pro optimised for 8K) and Nano Color (“filtering out impurities to enhance color reproduction”). 

The 75SM9900PTA has an Australia RRP of $11,849. More info on that model HERE.

Both the OLED and NanoCell TVs feature support for Dolby Vision and Advanced HDR by Technicolor up to 4K, and HLG and HDR10 up to 8K. All four HDMI ports support HDMI 2.1 (8K/60-capable) plus automatic low latency mode (ALLM), variable refresh rate (VRR) and enhanced audio return channel (eARC).

Also supported is Apple’s AirPlay 2 and HomeKit.