TCL C8L / QM8L vs LG OLED C6 (WOLED)

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.

The HDR performance of the LG C6 is really very good. LG Display’s new WOLED panel has mainly brought a significant increase in brightness. In our unit we measured around 1500 nits and, importantly, the TV can show similar values in many normal movie scenes as well. That gives HDR real punch. Bright highlights, lamps and sunlight can be genuinely intense, and most HDR movies simply look very impressive. Of course it’s still an OLED, so brightness falls in scenes with a lot of white. The fifth scene from the movie The Meg illustrates this well, where the C6 reached around 600 to 700 nits. That’s still a very good result, but it also shows the new panel hasn’t shed all the limitations typical of OLEDs.

Colours

When it comes to colours, it’s also hard to raise major objections. The C6 covers about 99% of the DCI-P3 gamut and roughly 75% of BT.2020. In practice colours are very saturated and, importantly, stable regardless of the scene. That’s worth emphasising, because not every TV behaves the same in this respect. In some RGB Mini LED models colour saturation can depend more strongly on image brightness. A wider colour gamut today is mainly offered by QD-OLED TVs and new SQD models with a new generation of quantum dots. However, the C6 still performs very strongly here and is able to produce suitably saturated colours in most movie scenes.

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.

Right out of the box the LG C6 is quite well set up, especially if you choose the Filmmaker mode. In SDR material the white balance is decent, although as brightness increases there is a slight lack of red. The image becomes a bit cooler, but not enough for it to be very noticeable during normal viewing. More is happening in the brightness characteristic. Gamma is a little low and instead of holding at 2.4, for a large part of the range it sits closer to 2.1–2.2. In practice the C6 slightly brightens midtones. Shadows are therefore more readable, but the image loses some depth compared with how it should look in a darkened room.

In HDR the situation is a bit more interesting. The start of the greyscale looks very good, but from about 20–30% brightness the white balance starts to drift increasingly. As brightness rises there is more red and a noticeable lack of blue. In the brightest sections the difference is already significant and also affects the reproduction of some colours. The EOTF curve itself is followed quite well through most of the range. The C6 only tends to slightly brighten the image, which we also saw in our film comparisons. The largest deviation appears around the brightest parts, where the TV starts adapting the signal to the panel's capabilities.

The factory Filmmaker setting in HDR is therefore not perfect, but overall performs well. The biggest area for improvement is the white balance, especially at high brightness.

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.

LG TVs have long responded very well to calibration, and the C6 is no exception. After adjustments we managed to set the white balance practically perfectly, and most colour errors fell below 3, often down to around 2. In practice this means very accurate colour reproduction in both SDR and HDR. An interesting detail only appeared with the HDR brightness response. On a classic EOTF chart everything looks almost perfect and at first glance it would be hard to find fault. Only when we measured the TV’s behaviour using filters based on real film scenes did it become clear that the C6 has a slight tendency to artificially boost image brightness.

It’s not a huge difference and many viewers may even see it as a positive, because HDR looks a bit more striking as a result. From the point of view of fidelity to the source material, however, it’s not ideal — some scenes are simply a touch brighter than the filmmaker intended. Interestingly, this is rather unusual for LG. In previous generations the brand’s TVs typically held very closely to the reference picture curve after calibration. The C6 is still very close to the standard, but that subtle brightness 'boost' can indeed be noticed in films and TV series.

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.

Here the LG C6 has taken a really big step forward. The TV uses the same processor found in the flagship G6, and in terms of image processing the two models are very close. That's a big plus, because in this area LG's processor this year performs excellently. The "Smooth Gradation" function works particularly well. With heavily compressed material it can effectively hide ugly tonal banding and artefacts that often appear, for example, in lower-quality streaming. It's best to leave it on the "Low" setting. Then the improvement is clear, and the TV doesn't yet start blurring fine detail. Higher levels smooth the image more aggressively, but can already remove some of the natural texture of objects on screen. Upscaling itself also performs very well. Lower-resolution content is properly sharpened, edges look clean, and the processor quite effectively reconstructs fine details. In that respect the C6 is really close to LG's best TVs and the differences compared with the G6 are small.

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 C6 features a panel with a maximum refresh rate of 165 Hz, which is great news especially for gamers using a powerful PC. For movies, sport and consoles we’ll of course be limited to 120 Hz at most, but even then it’s hard to fault the motion clarity. As you’d expect from an OLED, the panel’s response time is near-instant. Moving objects therefore don’t leave the characteristic smearing you still see on LCD TVs. This is especially noticeable in sport and fast-paced games, where the picture remains very clean even during dynamic movement.

For movies and TV, LG has also included a motion smoothing system called TruMotion. In the user settings you’ll find two separate sliders. De-Judder is primarily for low-frame-rate material, namely movies and TV series at 24 fps. You can use it to slightly reduce the characteristic judder or increase it if you prefer a much smoother picture. De-Blur, on the other hand, is useful for higher-frame-rate content, mainly sports broadcasts and 50/60 fps TV.

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.

LG has long focused heavily on gamers, and the C6 essentially lacks nothing important. The TV supports 4K at 120 Hz from consoles, and when connected to a PC it can even run at 165 Hz. On top of that there’s VRR from 40 to 165 Hz, ALLM and a properly functioning HGiG. Another big plus is support for Dolby Vision in games, so the Xbox Series X can use that format without giving up game mode. The package is rounded out by the Game Bar, which lets you quickly check key signal parameters and change settings without leaving your game. In terms of features alone, the C6 is one of those TVs it’s really hard to fault. Whether you play on PlayStation, Xbox or PC, practically everything you could expect from a modern gaming TV is available here.