Tuesday, 29 May 2018

5 reasons why QLED, not OLED, might be the future of TVs

If there's one thing we've come to expect from the TV market, it's that there'll always be competing formats and technologies for the consumer to fret over. A decade ago, it was all about plasma vs LCD, with each TV technology presenting a number of benefits and disadvantages. Although the differences in today's TV technologies are perhaps more granular and specific, they're no less important.

With many AV enthusiasts currently focused on the high-dynamic-range format war (pitting HDR10 against Dolby Vision and now HDR10+ and HLG), a new battle for TV tech supremacy has emerged in OLED vs QLED

While most people are aware of OLED's status as a high-end TV technology (having been in the public eye much longer than Quantum Dot-powered rivals), there's still an air of mystery surrounding QLED, particularly in regards to how it works and why you might want to choose it over other television technologies. 

TV-makers Samsung, Hisense and TCL are all very confident in the technology, with the three electronics companies forming the QLED Alliance together in an attempt to tackle OLED head on. 

To get more of an understanding of how QLED works, we met up with some of Samsung’s engineers in Ho Chi Minh City, Vietnam – home of the Korean company's QLED facilities – to get an insider's look at the burgeoning quantum dot-powered technology. We left with a better understanding of the technology and how its implementation has improved since the last year, and we also got to see how it directly compared to the competition. 

While many AV enthusiasts consider OLED to be the gold standard in TV display technology (thanks in large part to its propensity for deep blacks and impressive contrast), its drawbacks are less widely discussed. 

QLED's strengths include unrivalled color performance – specifically when it comes to color accuracy and color volume – which directly address some of OLED's weaknesses. And in 2018, new approaches to backlighting have also brought QLED closer than ever before to achieving a similar "pure black" effect to what OLED boasts.

With that in mind, we've put together a list of the top five reasons for why QLED, and not OLED, might just be the future of flatscreen TVs.

Its black levels are improving

Though not inherently related to QLED technology, the combination of Quantum Dots and Full Array Local Dimming (FALD) has resulted in an effect that arguably presents the best of both worlds in terms of brightness and deep blacks. Colors and whites appear brighter and more vibrant, while blacks appear deeper and with less backlight bleed.

FALD employs hundreds of tiny backlights across the entire panel, allowing the television to precisely control the areas of the screen that receive light. These are called 'local dimming zones'.

In contrast to OLED, which uses self-lighting pixels instead of backlights, FALD is able to achieve far brighter highlights, making the difference between black and white areas of the screen even more pronounced.

Last year, Samsung's QLED TVs still relied on older edge-lit backlight technology, which spreads light across the panel from the sides of the display in a less-accurate manner. With the inclusion of FALD in the 2018 Q8F and Q9F ranges, that issue has been tackled head on – with impressive results.

In one demonstration we saw in Vietnam, Samsung shuffled us into a darkened room to witness a direct comparison between its edge-lit QLED models from last year, its FALD QLED models from this year, and an unspecified competitor's 2018 OLED television. 

Each television featured a scene from the film La La Land, in which Ryan Gosling's character plays piano to a darkened room – a ray of light piercing in from the corner of the screen to reveal the piano player and a small portion of his audience.

The 2017 edge-lit QLED models came out poorest, showing a very obvious ring of light around the entire center of the image, making it appear as if Gosling was playing the piano from within a hazy bubble. Of course, the OLED television's perfect blacks were on full display, however we were struck by how close the 2018-model QLED came to achieving the same effect. No light leakage or banding was present at all, and instances of obvious light blooming were completely absent.

It has greater color accuracy

A major selling point of Quantum Dot technology is its propensity for achieving astonishing color accuracy. In essence, QLED is quite similar to LED TV technology, in that color is distributed with the use of LED light and the RGB particle. However, things change drastically with the inclusion of Quantum Dot particles. 

When light hits the tiny quantum dot semiconductor particles (we're talking anywhere from a few to several nanometers in size) featured in QLED televisions, they emit incredibly accurate red, green or blue colors on screen. Color is determined by the size of the quantum dots. 

In terms of how this affects your television viewing, the answer is simple: it allows for much greater accuracy when it comes to rendering colors, which means images are much closer to how things look in real life. 

Coming back to our La La Land example scene from earlier, on the lit-up portions of the picture, the 2018 QLED images were bright and clear, while the OLED screens' appeared comparatively dim and muted – skin tones had a slightly greener tinge, making the characters appear somewhat lifeless and unhealthy, and the dark areas of the screen were almost too dark, with less detail present in shadows.

While watching BBC documentary-series Planet Earth II, QLED's advantages became even more apparent. The greens of the rainforest appeared more vibrant and natural, with a real warmth becoming evident in the oranges and brown hues within the image. That warmth was notably less prominent on the OLED display. 

It's one thing to look at an image and judge a TV's color by how aesthetically pleasing it appears to be, but the only way to really appraise its accuracy is to compare it to offscreen elements in the real world. 

In an effort to put its color accuracy to the test, a Samsung rep placed a Pantone color card against the screen of the quantum dot-powered Q9F television to show how closely it matched the colors on the card (spoiler alert: the colors on each looked exactly the same). Next, the card was placed against the same image on an OLED display, revealing a completely different, darker shade entirely. 

Even taking into account things like brightness and color settings, the evidence was fairly irrefutable – QLED leaves OLED for dead in terms of color accuracy.

It doesn't suffer from burn in

Unlike the organic light-emitting diode, better known as OLED, all of the materials used in QLED displays are inorganic. But wait — aren't organic things meant to be better? Not necessarily – at least in the case of expensive display technology. Why? Because the laws of nature dictate that organic materials suffer decomposition and decay over time. Remember burn in on plasma TVs, where images would get 'stuck' on the screen if they were displayed for too long? OLEDs can suffer from the same kind of problem. 

QLED televisions side-step this problem entirely, as the materials used in quantum dot technology are completely inorganic, meaning they're not susceptible to burn in issues. 

To greater understand the effects of burn in, we looked at two identical CNN broadcasts on OLED and QLED displays. As is usually the case with news programs, the anchor sat in the center of the screen surrounded by logos, boxouts and scrolling text at the bottom of the panel. 

Both images looked pretty decent (albeit with warmer skin tones on the QLED), however when each TV was switched off, the differences between the two sets were instantly recognizable. 

The QLED set showed no signs of burn in whatsoever – the switched-off screen was just a pristine, unaffected black rectangle. Meanwhile, the OLED's screen left behind a burnt-in ghost of what was previously on the display – complete with a visible CNN logo, boxes and the newscaster's silhouette.

Now, we have no way of realistically ascertaining how long each display was stuck displaying the same image, though it's worth noting that the OLED TV was a 2018 model, meaning it was already surprisingly compromised just a few months after release. 

If you watch a lot of programmes with static onscreen elements, QLED's clearly more robust. Samsung, in particular, seems assured of the tech's ongoing durability, offering a 10-year no burn in guarantee on its 2018 QLED range. Time will tell how that pans out, though it seems like a pretty confident promise. 

It can get insanely bright

We briefly spoke about backlighting and color volume in QLED TVs (and how they compare to OLED technology) earlier, but brightness is another extremely important element to consider when looking for a TV to buy, so it's worth examining in a bit more detail.

Because OLED's pixels are self-lighting, they don't use any kind of backlighting system. The pixels themselves do the heavy lifting, going from completely switched off to white (or whichever color it may be) when activated. 

While this allows OLED to achieve its much-celebrated pure blacks at a per-pixel level, it also means that the image itself is unable to get as bright as something with a backlight behind it. When combined with a Full Array Local Dimming system, QLED's 100% color volume capabilities allow content to go from 'just fine' to 'dazzling and vibrant'.  

Going back to that La La Land demonstration from earlier, even the bright areas of the OLED image looked relatively subdued and dull when compared to the QLED display sitting directly above it. The QLED version looked considerably more striking and vivacious, something that was particularly pronounced when the lights in the scene come on to reveal a full musical stage performance.

Although Samsung's Quantum Dot materials have remained unchanged since last year, the company has made some significant tweaks in terms of calibration, achieving a full DCI-P3 colour gamut at both very low and high brightness levels. Current QLED sets can even reach 2000 nits of brightness in some instances, well above the roughly 700 nits common on 2018 OLEDs.

Being able to output higher brightness isn't just about more vibrant onscreen images either – ultimately, it makes for a more flexible display that's able to provide clear visuals in more situations, such as brightly-lit rooms where an OLED might struggle. 

It has the best HDR performance

Going back to QLED's affinity for brightness, color accuracy and color volume, the combination of quantum dots and high-dynamic-range (HDR) content allows for images that burst with vivid and life-like color.

As opposed to standard-dynamic-range (SDR) content, HDR allows for a much wider color gamut to be displayed on screen. In the case of QLED, that means over a billion colors, meaning content creators, especially filmmakers and games developers, are able to display their works in a way that's as close to their original vision as possible. 

HDR is especially important when it comes to lighting and shadows — a wider color gamut means more visible detail and shading on your screen, with less obvious banding and gradations emitting from light sources.

Streaming services like Netflix and Amazon Prime Video already offer plenty of 4K HDR shows and movies to make the best of QLED's pure color capabilities, and further HDR content is available on iTunes and on 4K Ultra HD Blu-ray

Relatively new to the high-dynamic-range scene is HDR10+, a format which employs dynamic metadata to adjust HDR mastering in a scene-by-scene manner — much like the HDR competitor Dolby Vision

Developed by Samsung in partnership with Panasonic and 20th Century Fox, the format promises to take full advantage of QLED's brightness and color accuracy strengths. At present, Amazon Prime has thrown its support behind HDR10+, while Netflix has said that it's open to supporting the format in the future. As you might expect, Samsung's new QLED range is also fully HDR10+ capable.

Can we crown a winner?

While it's perhaps a little too early to claim that QLED will ultimately come out on top in today's TV-tech battle, what's clear is that it already has enough strengths to pose serious competition to OLED,  in some of the most critical areas of display performance.

While OLEDs have begun flooding the market over the last few years, with several major brands now competing in the space, QLED's particular set of visual skills already make it an attractive competitor – and one that's definitely worthy of consideration in 2018.

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