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 has a direct impact on real film scenes. The television flawlessly pulls out details in the bright parts 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's protection system (ABL). However, in real, varied film shots, this value still hovers around 2000 nits, which can be considered an outstanding result. The coverage of the color palette also deserves praise. The new 2nd generation Tandem OLED panel brought only a cosmetic change, but still an improvement. The DCI-P3 color gamut coverage reaches nearly 99.5%, while the ultra-wide BT.2020 is around 84%. These are very good results, although one must 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 a white sub-pixel (WOLED). However, in everyday content and most films, detecting this difference will be very difficult.

In terms of HDR, the TCL C8L turns out to be a hellishly bright television – and I mean literally. On a synthetic chart of 5%, our measuring equipment indicated a result exceeding 4500 nits. This is a result that is downright cosmic, considering that reference director monitors, 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 exactly. Dry synthetic tests are one thing, and real movie images are another. In real, varied scenes, the C8L achieves a peak of around 1600 nits. This is still a very good result, ensuring a very high level of HDR dynamics, but also clearly lower than what the manufacturer boasts in the specifications. The trouble starts with very small flashes of light – then brightness can drastically drop to around 600 nits. The algorithm tries at all costs to maintain deep black and minimize halo effect, but it does so at the expense of HDR impact. This is perfect evidence that laboratory charts rarely correspond to what we ultimately see on the screen.

Huge applause is due for color 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 true jaw-dropper is the measurement of the extremely demanding BT.2020 space. The C8L achieves as much as 90% in it, placing it alongside today's top screens that boast RGB backlighting. Importantly, unlike some screens with Micro/Mini RGB backlighting, this effect is stable regardless of the scene displayed. Of course, one must remember that content mastered for such a wide gamut in films or series is still a rarity. However, the mere fact that the panel has such a "color reserve" deserves immense admiration.

We tested the LG G6 in the best factory mode for color fidelity, which is FILMMAKER MODE. For our test unit, this mode was fairly well-tuned right out of the box. In SDR content, the only thing we could nitpick was the white balance, which leaned towards warmer tones. As a result, the image could sometimes appear slightly yellowed; however, overall, it wasn't a bothersome issue. The G6 performed a bit worse with HDR content. There, we noticed too much blue component in the white balance. This caused the image to take on cooler shades, resulting in quite noticeable errors. As can be seen in our ColorChecker chart, colors were indeed shifting towards these cooler registers. Nevertheless, for factory settings, the television displayed a completely decent level. However, we know that OLED screens – especially those from LG – respond wonderfully to professional calibration, which is why we immediately proceeded with it.

We tested the TCL C8L in the best factory picture mode available in this TV’s menu for image fidelity. That, of course, is Filmmaker Mode, which appeared in this brand’s software relatively recently (a year ago in the "K" series). Thanks to it, an average user can get a pretty good color reproduction straight out of the box, although it is certainly not a perfectly tuned mode. Looking at the factory white balance of our unit, both in SDR and HDR material, the red component was clearly lacking, which made the image noticeably cooler and caused a slight shift toward bluish-green tints. The issue of brightness management is also ambiguous, as we mentioned earlier. While for SDR content the gamma linearity is actually correct and holds steadily at the reference value of 2.4, in HDR things look much worse. Tracking the EOTF curve clearly shows the TV has a significantly boosted brightness across the range, which can make the final image overly bright and inconsistent with the creators’ intent, and that in a mode that by definition should avoid that. Of course, like every sample in our lab, this one also underwent professional calibration, and its results are shown below.

After conducting a professional calibration, we gained complete control over the panel, and we were able to adjust all parameters to nearly zero. We managed to perfectly tune the white balance, which made the factory-cool and warm tints disappear from the screen. The effects are clearly evident in the ColorChecker test – the average color reproduction errors dropped below the critical value of 1-2. And what does that mean? PERFECT colors, with no distortion whatsoever! However, from a reviewer's obligation, we must comment on how the LG G6 autonomously manipulates brightness, for which the EOTF curve is responsible. When we look at the standard synthetic graph, it may seem that the line is quite straight. The situation changes, however, when we turn on the measurement filter, which shows how the television interprets brightness in real, moving film scenes (EOTF in MOVIES). At that point, it becomes clear that some of the smallest fragments 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 the best television of the year.

As you can see, the results of a professional calibration of the TCL C8L are really promising, thanks to the extensive adjustment tools the manufacturer put at our disposal in the menu. Above all, we were able to completely correct the white balance — we eliminated the red deficiency, so the image finally stopped drifting toward unwanted cool tones. After that adjustment, errors in the ColorChecker test fell to near-reference levels, regularly landing below a Delta E of 2, which is below the threshold of human perception.

If the test patterns look this 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 actual movie material (I recommend enabling the EOTF filter when watching movies), you can see that in most scenarios the TV still reacts to HDR metadata its own way. As a result, the picture can be slightly over-brightened and not faithful to the creators' intent, and it was precisely this lack of consistency with real films that cost the C8L a few points.

No matter what one may say about the G6's problems with near-black signal, it must be fairly acknowledged that it handles highly compressed material and lower resolution content brilliantly. All unwanted, ugly tonal transitions are effectively reduced here by the “Smooth Gradation” feature. On the “Low” setting, the algorithm operates flawlessly – effectively masking the artifacts resulting from strong compression, without destroying the sharpness and details in the frame. Higher levels of this feature indeed smooth the image even more, but they start to blur the real texture elements of objects, which is why we recommend keeping this slider at a low level. 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 respect, the G6 does not lag behind the world's best.

This year the C8 series and higher models received probably the biggest and most anticipated upgrade in TCL’s history, and it specifically concerns digital image processing. The C8L is the lowest-end model in the manufacturer's lineup to be equipped with the latest flagship chip, the MediaTek Pentonic 800 (listed in the menu as MT9655). Thanks to its processing power, the feature called "Gradual Smoothing" finally works as it should. The algorithm effectively eliminates unwanted posterization (ugly tonal transitions/color banding), 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 evaluating this element can be mostly 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 to the competition.

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

The TCL C8L is equipped with a fast panel that has a native 144 Hz refresh rate. That spec will be most appreciated by demanding PC gamers, while most users, who rely on consoles or TV broadcasts, will use a steady 120 Hz. It is at 120 Hz that motion processing algorithms handle image rendering for movies, series, and sports. In the TV’s menu you’ll find a "Motion Clarity" option that lets you adjust the motion smoothing to your preferences. The algorithms handle cinematic material at 24 or 30 frames per second (fps) as well as dynamic sports broadcasts at 50 or 60 fps, maintaining appropriate smoothness.

LG G6 is a true monster for gamers and one of the best-equipped TVs in this regard on the market. The manufacturer did not seek compromises and equipped 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 your PlayStation 5, Xbox Series X, or powerful PC into, you will extract the absolute maximum from them.

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

For gamers – especially for those with powerful PCs and several consoles at the same time – the TCL C8L is a true beast. It’s the first model in the manufacturer’s lineup equipped with four full HDMI 2.1 ports with a maximum bandwidth of 48 Gbps. This is directly thanks to the new Pentonic 800 processor we wrote about earlier. Additionally, the TV seamlessly supports virtually every gaming feature. It has 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. We’re also talking about standards like G-Sync or FreeSync from Nvidia and AMD. When it comes to image display standards, there are also no compromises: the C8L offers complete support for HDR formats in games, including gaming Dolby Vision and the HGiG profile. All of these features can be conveniently managed from a very readable game bar (Game Bar), which we can customize according to our preferences. From a purely gaming perspective, there really isn’t anything to complain about in the C8L – well, maybe aside from the previously mentioned slight ghosting. But other than that? It’s an unflawed machine for gamers.