LG OLED G6 (G64LW, G66LS) vs TCL C8L / QM8L

The LG G6 is currently one of the brightest OLEDs on the market. Its peak brightness reaches nearly 2500 nits, and what’s best – this has a direct impact on real film scenes. The television flawlessly extracts details in the bright areas of the image. And this is regardless of whether we are talking about very small points like stars in the sky or slightly larger elements on the screen. Naturally, with full-screen, uniformly white scenes, the brightness of the G6 decreases due to the panel protection system (ABL). However, in real, varied cinematic shots, this value still hovers around 2000 nits, which can be considered an outstanding result. The coverage of the colour palette also deserves praise. The new second-generation Tandem OLED panel only brought a cosmetic change but still an improvement. The coverage of the DCI-P3 palette reaches nearly 99.5%, whereas for the ultra-wide BT.2020, it is around 84%. These are very good results, although it’s worth remembering one thing: at extremely high brightness levels, the colour volume will be lower than in Samsung Display’s QD-OLED panels due to the use of a white sub-pixel (WOLED). However, in everyday content and most films, catching this difference will be very difficult.

In terms of HDR, the TCL C8L turns out to be a hellishly bright television – quite literally. On a synthetic test pattern sized at 5%, our measurement equipment indicated a result exceeding 4500 nits. This is a truly astronomical result, considering that reference monitors used by directors, which we often refer to in our materials, typically operate around 4000 nits. Does this mean that the C8L breaks barriers and climbs to the technological peak of Mini-LED? Not quite. Dry synthetic tests are one thing, while real cinematic images are another. In real, varied scenes, the C8L peaks at around 1600 nits. This is still a very good result, ensuring a very high level of HDR dynamics, but it is also clearly lower than what the manufacturer boasts in the specifications. The problems begin with very small bursts of light – at that point, brightness can drastically drop to around 600 nits. The algorithm tries at all costs to maintain deep blacks and minimise the halo effect, but this comes at the expense of HDR impact. This is perfect evidence that laboratory test patterns rarely align with what we ultimately see on the screen.

However, huge praise is due for colour reproduction, thanks to the new generation of SQD (Super Quantum Dot) quantum dots. The DCI-P3 colour gamut coverage reaches 97%, but the truly jaw-dropping measurements come from the extremely demanding BT.2020 space. The C8L achieves an impressive 90% in this space, placing it alongside today's top screens equipped with RGB backlighting. Importantly, unlike some screens with Micro/Mini RGB backlighting, this effect is stable regardless of the scene displayed. Of course, it’s worth remembering that content mastered for such a wide gamut in films or series is still rare. However, the very fact that the panel has such a "colour reserve" deserves tremendous admiration.

We tested the LG G6 in the best factory mode in terms of colour fidelity, namely FILMMAKER MODE. In the case of our test unit, this mode was quite well tuned straight out of the box. In SDR content, the only issue we could point out was the white balance, which tended to drift towards warmer tones. Consequently, the image could occasionally appear slightly yellowed; however, overall, this was not an bothersome problem. The G6 performed a bit worse with HDR content. There, we noted too much blue component in the white balance, which caused the image to take on cooler hues, resulting in fairly noticeable errors. As can be seen in our ColorChecker chart, the colours indeed drifted towards these cooler registers. Nevertheless, considering the factory settings, the television displayed a perfectly decent level. We do know, however, that OLED screens – particularly those from LG – respond excellently to professional calibration, which is why we immediately went ahead with it.

We tested the TCL C8L in the best factory mode available in the TV’s menu for image fidelity. That’s of course Filmmaker Mode, which only arrived in this brand’s software relatively recently (a year ago in the "K" series). It allows the average user to achieve quite decent colour reproduction straight out of the box, though it is certainly not perfectly tuned. Looking at the unit’s out-of-the-box white balance — in both SDR and HDR material — the red component was clearly lacking, which made the image noticeably cooler and slightly shift towards blue‑green tints. The issue of brightness management also looks ambiguous, as we mentioned earlier. While the gamma linearity in SDR content is really good and stays steadily at the reference value of 2.4, the situation in HDR is much worse. Tracking the EOTF curve clearly shows the TV has a noticeably boosted brightness across the entire range, so the final image can be excessively bright and inconsistent with the creators’ intent, and this is in a mode that by definition should avoid that. Of course, as with every sample in our lab, we subjected this one to professional calibration, and you can find the results below.

After professional calibration, we gained complete control over the panel, and we managed to align all parameters to nearly zero. We successfully calibrated the white balance perfectly, which eliminated the factory cool and warm tints from the screen. The effects are clear as day in the ColorChecker test – the average colour reproduction errors dropped below the critical value of 1-2. And what does that mean? PERFECT colours, without any distortion! However, as reviewers, we must point out here how the LG G6 arbitrarily manipulates brightness, for which the EOTF curve is responsible. When looking at the standard synthetic chart, it might seem that the line is quite straight. However, the situation changes when we turn on the measurement filter, which shows how the television interprets brightness in real, moving film scenes (EOTF in MOVIES). Then it becomes evident that some of the tiniest parts on the screen are slightly over-brightened by the algorithm. Of course, for the average viewer, such a deviation will be practically unnoticeable, but in the test of such an expensive screen, it is worth noting – especially since we are talking about a model that has huge aspirations to be named the best television of the year.

As you can see, the results of a professional calibration of the TCL C8L are truly promising, thanks to the comprehensive calibration controls the manufacturer has provided in the menu. Above all, we managed to fully correct the white balance, eliminating the red deficiency, so the image finally stopped drifting into unwanted cool tones. After that adjustment, the errors in the ColorChecker test fell to near-reference values, consistently sitting below a Delta E threshold of 2, i.e. below the visibility threshold for the human eye.

If test patterns look so perfect, you may ask us why the final score in this category is lower. The answer lies in the brightness management described earlier. Although the menu includes sliders that let you precisely straighten the EOTF curve on synthetic signals, when faced with real film material (I recommend enabling the EOTF filter when watching films), it becomes clear that the TV, in most scenarios, still responds to HDR metadata in its own way. As a result, the picture can be slightly over-bright and not faithful to the filmmakers' intent, and it is precisely for this lack of consistency with real films that we had to take a few points off the C8L's score.

Whatever one may say about the G6’s problems with near-black signal, it must be fairly acknowledged that it handles heavily compressed material and lower resolution content exceptionally well. All unwanted, unsightly tonal transitions are effectively reduced here by the "Smooth Gradation" feature. At the "Low" setting, the algorithm works flawlessly – effectively masking the artefacts resulting from strong compression without destroying the sharpness and details in the frame. Higher levels of this function do indeed smooth the image further, but they start to blur the real elements of object texture, which is why we recommend keeping this slider at a low setting. As for the upscaling to 4K, the processor does an excellent job – edge sharpness and detail reconstruction are at the highest level, and in this regard, the G6 does not fall behind the world leaders at all.

This year the C8 series and the higher-end models have probably received the biggest and most eagerly awaited upgrade in TCL’s history, and it concerns digital picture processing. The C8L is the entry-level model in the manufacturer's line-up that has been equipped with the latest flagship chip MediaTek Pentonic 800 (listed in the menu as MT9655). It is thanks to its computing power that the feature called "Gradual Smoothing" finally works as it should. The algorithm effectively removes unwanted posterization (ugly tonal transitions / colour banding) from the image, doing so intelligently enough that it does not degrade the sharpness of other details.

The processor also handles upscaling lower-resolution content to 4K very well. Although assessing this element can be largely academic, because the differences between today’s TVs in this class are very subtle. The most important takeaway is that TCL finally has nothing to be ashamed of compared with the competition.

LG G6 is an OLED television, so in the category of motion fluidity, it traditionally deserves the highest marks. The television supports very high refresh rates reaching up to 165 Hz in 4K resolution, but most importantly – on the screen, you will not notice any signs of blurring. The response time of the panel is almost instantaneous, ensuring that dynamic images remain perfectly sharp.

The TCL C8L is equipped with a fast panel with a native refresh rate of 144 Hz. This specification will be most appreciated by demanding PC gamers, while most users, who rely on consoles or TV broadcasts, will make use of a stable 120 Hz. It is at 120 Hz that the motion-processing algorithms take care of image processing (in films, series and sports). In the TV menu you'll find a "Motion Clarity" tab that allows you to tailor the motion smoothing to your own preferences. The algorithms cope well with both cinematic productions at 24 or 30 frames per second and with fast-paced sports broadcasts at 50 or 60 frames per second, ensuring appropriate smoothness.

The LG G6 is a true monster for gamers and one of the best-equipped televisions on the market in this regard. The manufacturer has not skimped on features, equipping this model with as many as four full HDMI 2.1 ports with a maximum bandwidth of 48 Gbps. This means that no matter which port you plug in your PlayStation 5, Xbox Series X, or powerful PC, you will get the absolute maximum performance from them.

The television supports a full set of gaming technologies: from VRR (Variable Refresh Rate) to AMD FreeSync Premium Pro, and even Nvidia G-Sync Compatible. On top of that, it offers remarkably low, nearly imperceptible input lag and an exceptionally well-functioning Game Optimizer panel, which allows you to monitor signal parameters in real time. Gaming on this screen, with the perfect black of OLED and impressive refresh rates, is pure pleasure.

For gamers – and especially for owners of powerful PCs and several consoles simultaneously – the TCL C8L is a true monster. It is the first model in this manufacturer's lineup to feature as many as four full HDMI 2.1 ports with a maximum bandwidth of 48 Gbps. This is directly attributable to the use of the new Pentonic 800 processor, which we discussed earlier. Additionally, the television seamlessly supports practically every gaming feature. We have an automatic game mode (ALLM) that reduces latency to minimal levels, and full frame synchronization (VRR) operating in an impressive range of up to 288 Hz. There's also talk of standards such as G-Sync or FreeSync from Nvidia and AMD. When it comes to display standards, there are no compromises either: the C8L offers complete support for HDR formats in games, including gaming Dolby Vision and the HGiG profile. We can conveniently manage all of these features from a very readable player bar (Game Bar), which we can personalise to our own preferences. From a purely gaming perspective, there's really nothing to fault the C8L on – well, maybe aside from the previously mentioned slight blurring. But other than that? It's a no-nonsense machine for gamers.