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, best of all, this translates directly to real movie scenes. The TV flawlessly extracts details in the bright areas of the image. And this is regardless of whether we are talking about very small points in the form of stars in the sky or slightly larger elements on the screen. Naturally, with full-screen, uniformly white scenes, the brightness of the G6 drops due to the panel protection system (ABL). However, in real, varied movie shots, this value still hovers around an impressive 2000 nits, which can be considered a remarkable result. The coverage of the color palette also deserves praise. The new 2nd generation Tandem OLED panel has brought about only a cosmetic change, but still an improvement. The coverage of the DCI-P3 color space reaches nearly 99.5%, while the ultra-wide BT.2020 is around 84%. These are very good results, although it's important to remember one thing: at extremely high brightness levels, the volume of colors will be lower than in QD-OLED panels from Samsung Display due to the use of white sub-pixels (WOLED). However, in everyday content and most films, capturing this difference will be very difficult.

When it comes to HDR, the TCL C8L turns out to be a hellishly bright television – and I mean that literally. On a synthetic test pattern of 5%, our measuring equipment indicated a result exceeding 4500 nits. That's an almost cosmic result, considering that reference director's monitors, which we often refer to in our materials, usually operate around 4000 nits. Does this mean the C8L breaks barriers and climbs to the technological peak of Mini-LED? Not quite. Dry synthetic tests are one thing, and real film images are another. In real, varied scenes, the C8L hits around 1600 nits at its peak. That's still a very good result, ensuring a very high level of HDR dynamics, but it's clearly lower than what the manufacturer boasts in the specifications. The trouble begins with very small bursts of light – then the brightness can drastically drop to around 600 nits. The algorithm does everything it can to maintain deep blacks and minimise halo effect, but it does so at the cost of HDR impact. This is ideal evidence that laboratory test patterns rarely correlate with what we ultimately see on the screen.

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

We tested the LG G6 in the best factory mode for colour fidelity, which is FILMMAKER MODE. In the case of our test unit, this mode was reasonably well tuned straight out of the box. In SDR content, the only issue we noticed was the white balance, which leaned towards warmer tones. This made the image occasionally appear slightly yellowish, but overall, it wasn't a significant problem. The G6 performed a bit worse in HDR content. There, the white balance showed too much blue component. This caused the image to veer towards cooler shades, resulting in quite noticeable errors. As can be seen on our ColorChecker chart, the colours shifted towards these cooler registers. Nevertheless, considering the factory settings, the television presented a perfectly decent level. However, we know that OLED screens – particularly those from LG – respond exceptionally well to professional calibration, so we immediately proceeded to do just that.

We tested the TCL C8L in the best factory mode available in the TV's menu for picture fidelity. I’m of course talking about Filmmaker Mode, which was introduced into this brand’s software relatively recently (a year ago in the K series). Thanks to it, the average user can get pretty good colour reproduction straight out of the box, although it’s certainly not perfectly tuned. Looking at the factory white balance of our unit, in both SDR and HDR content, there was a clear lack of the red component, which made the picture noticeably cooler and slightly shifted towards bluish‑green hues. The issue of brightness management is also ambiguous, as we mentioned earlier. While in SDR content the linearity of the gamma parameter is really good and consistently holds the reference value of 2.4, things are much worse in HDR. Tracking the EOTF curve clearly shows the TV’s brightness is considerably boosted across the range, which can make the final image overly bright and inconsistent with the creators’ intent, and that is in a mode that by definition should avoid this. Of course, like every unit in our lab, this one was also subjected to professional calibration, and you can find the results below.

After completing a professional calibration, we gained complete control over the panel, and we managed to align all parameters to nearly zero. We were able to tune the white balance perfectly, which removed the factory's cool and warm tints from the screen. The effects are visibly clear in the ColorChecker test – the average colour reproduction errors dropped below the critical value of 1-2. And what does this mean? PERFECT colours, without any distortion! However, as a reviewer’s duty, we must point out how the LG G6 arbitrarily manipulates brightness, which is due to the EOTF curve's behavior. When we look at the standard synthetic graph, 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 actual, moving film scenes (EOTF in MOVIES). Then, it is clear as day that some of the smallest fragments on the screen are slightly overly brightened by the algorithm. Of course, for the average viewer, such a deviation will practically go unnoticed, but in the test of such an expensive screen, it’s worth noting – especially since we are talking about a model that has huge aspirations for the title of the best television of the year.

As you can see, the results of a professional calibration of the TCL C8L are genuinely promising, thanks to the extensive adjustment tools the manufacturer made available in the menu. Most importantly, we were able to fully correct the white balance, eliminating a lack of red so the image finally stopped drifting into unwanted, cool tones. After this step, errors in the ColorChecker test fell to near-reference values, regularly sitting below a Delta E threshold of 2, which is under the level noticeable to the human eye.

Since the test patterns look so perfect, you might ask: why then the lower final score in this category? The answer lies in the brightness management discussed earlier. Although the menu includes sliders that let you precisely straighten the EOTF curve on synthetic signals, when confronted with real film material (I recommend turning the EOTF filter on 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 image can be a touch too bright and not in line with the creators' intent, and it was precisely for this lack of repeatability with real-world films that we had to dock the C8L a few points.

No matter what one might say about the G6's issues with near-black signal, it must be fairly acknowledged that it handles heavily compressed material and lower resolution content extremely well. All unwanted, ugly tonal transitions are effectively reduced here by the "Smooth Gradation" feature. At the "Low" setting, the algorithm works flawlessly – effectively masking the artifacts resulting from strong compression without destroying the sharpness and details in the frame. Higher levels of this feature do further smooth the image, but they start to blur the real texture elements of the objects, so we recommend keeping this slider at a low level. As for the actual upscaling to 4K, the processor does an excellent job – edge sharpness and detail reconstruction are at the highest level, and in this respect, the G6 is on par with the global leaders.

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's to do with digital image processing. The C8L is the entry-level model in the manufacturer's line-up to be fitted with the latest flagship MediaTek Pentonic 800 chipset (shown in the menu as MT9655). It is thanks to its processing power that the feature called "Gradual Smoothing" finally works the way it should. The algorithm effectively removes unwanted posterization (ugly tonal transitions / colour banding) from the picture, 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 judging this element can be purely academic, because the differences between today's TVs in this class are very subtle. The most important point is that TCL finally has nothing to be ashamed of compared with the competition.

The LG G6 is an OLED television, so in the category of motion fluidity, it traditionally deserves the highest marks. The TV supports very high refresh rates of up to 165 Hz in 4K resolution, but most importantly – there are absolutely no signs of blurring on the screen. The response time of the matrix is virtually instant, ensuring that dynamic images remain perfectly sharp.

The TCL C8L is equipped with a fast panel with a native 144 Hz refresh rate. That spec will be most appreciated by demanding PC gamers, while most users, relying on consoles or TV broadcasts, will use a steady 120 Hz. And it is at 120 Hz that the motion-processing algorithms take care of image processing for films, series and sports. In the TV's menu you'll find a "Motion Clarity" option that lets you customise the motion smoothing to your preferences. The algorithms handle both cinematic productions at 24 or 30 frames per second and fast-paced sports broadcasts at 50 or 60 frames per second, maintaining the right level of smoothness.

The LG G6 is a true beast for gamers and one of the best-equipped TVs on the market in this regard. The manufacturer didn't compromise and equipped this model with 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'll get the absolute maximum performance out of them.

The TV supports a full suite of gaming technologies: from VRR (Variable Refresh Rate), to AMD FreeSync Premium Pro, and Nvidia G-Sync Compatible. Let's add to that a remarkably low, almost imperceptible input lag and an excellently functioning game panel (Game Optimizer), which allows you to constantly monitor signal parameters. Gaming on this screen, with the perfect black of OLED and powerful refresh rates, is pure pleasure.

For gamers – especially for owners of powerful PCs and multiple consoles simultaneously – the TCL C8L is a true beast. This is the first model in this manufacturer's lineup that is equipped with four full HDMI 2.1 ports with a maximum bandwidth of 48 Gbps. This is directly due to the use of the new Pentonic 800 processor, which we've mentioned before. Additionally, the TV seamlessly supports practically every gaming feature. It has an automatic game mode (ALLM) that reduces latency to minimal levels, as well as full variable refresh rate (VRR) operating in an impressive range of up to 288 Hz. It also supports standards such as G-Sync and FreeSync from Nvidia and AMD. When it comes to image display standards, there are no compromises either: the C8L offers complete support for HDR formats in gaming, including gaming Dolby Vision and the HGiG profile. We can conveniently manage all these features from a very readable gamer bar (Game Bar), which we can customise according to our own preferences. From a purely gaming perspective, the C8L really has no flaws – well, maybe apart from the previously mentioned slight ghosting. But other than that? It’s a no-nonsense machine for gamers.