TCL C6K vs TCL C8L / QM8L

TCL C6K is a moderately bright TV that can showcase its full potential under the best cinematic conditions – the maximum brightness is around 600 nits. In scenes with large, intense light sources, the HDR effect can be really satisfying, providing a sense of cinematic brilliance. However, it should be noted that when managing the backlighting zones, there are situations where some elements become dimmed and sometimes can even become barely visible. It is clear that there is a lack of proper algorithm optimization here, although looking at the technical parameters in this price range, the design itself performs very well.

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.

This year's TCL televisions feature a Filmmaker mode, and it must be admitted that it is definitely the best choice straight out of the box. This is the mode we recommend for everyday watching of movies and series. Unfortunately, as is often the case, the best doesn't mean perfect. In the case of SDR content, the image was too warm because the red was strongly emphasized in the white balance. On the other hand, with HDR content, we had the opposite impression – the image became cooler than it should have been due to excess blue. Additionally, the brightness characteristic sometimes led to highlights being blown out. In practice, this resulted in quite noticeable color test inaccuracies that are hard to accept in a mode advertised as "by the creators."

We tested the TCL C8L in the best factory mode available in the menu of this television for image fidelity. We are, of course, talking about Filmmaker Mode, which has been part of this brand's software structure relatively recently (a year ago in the "K" series). Thanks to it, an average user can achieve quite a good color reproduction straight out of the box, although it is certainly not a perfectly calibrated mode. Looking at the factory white balance of our model – both in SDR and HDR materials – it was clear that the red component was noticeably lacking, which made the image appear noticeably cooler and slightly lean toward bluish-green hues. The issue of brightness management is also ambiguous, which we mentioned earlier. While in SDR content, the linearity of the Gamma parameter is really good and it reliably maintains the reference value of 2.4, in HDR the situation looks much worse. Following the EOTF curve clearly shows that the television has significantly boosted brightness across the range, which can cause the final image to be excessively bright and inconsistent with the creators' intentions – and this in a mode that should, by definition, avoid this. Of course, like every unit in our lab, this one was also subjected to professional calibration, and its results can be found below.

Thanks to the white balance correction, it was possible to significantly reduce the C6K's tendency to distort colors, which resulted in a very good final outcome. After calibration, we will no longer observe the effect of excessive warming of scenes in SDR or overly cooling the image in HDR. However, it is worth taking a closer look at the brightness characteristics. In SDR content, there are few complaints – the image looks really good, especially in older movies, TV shows, or materials from YouTube. This is much worse for HDR content. Analysis of the EOTF curve suggests that everything is fine, but in practice (EOTF in films), the limitations of the construction become apparent. The TV tends to overly brighten the smallest parts of the frame, and in other situations, it can dim the entire scene too much. The effect of calibration is therefore evident, and in terms of color, the C6K has gained quite a lot, but certain limitations arising from local dimming and, in fact, its management by the C6K simply cannot be overcome.

As you can see, the results of the professional calibration of the TCL C8L are truly promising, thanks to the extensive adjustment tools that the manufacturer has made available to us in the menu. Above all, we managed to completely correct the white balance – we eliminated the red deficiency, resulting in the image no longer drifting into unwanted, cool shades. After this adjustment, the errors in the ColorChecker test dropped to nearly reference values, regularly placing below the Delta E threshold of 2, which is below the visibility limit for the human eye.

Since the test patterns are so perfect, you might ask us: why, then, is the final rating in this category lower? The answer lies in the brightness management previously described. Although we find sliders in the menu that allow us to precisely straighten the EOTF curve on synthetic signals, in confrontation with real film material (I recommend turning on the EOTF filter in movies now), it is clear that the television, in most scenarios, still responds to HDR metadata in its own way. As a result, the image can be slightly overexposed and not consistent with the creators' intentions – and it is precisely for this lack of repeatability in real films that we had to deduct a few points from the C8L model.

The TCL C6K performs quite well in terms of scaling. Lower quality materials look acceptable, and the lack of overscan issues means that the image is displayed in full, without cropping. However, one cannot expect miracles – content of very low quality will not gain new life here, as the image processor has its limitations. On thin lines or details, the characteristic tearing is visible, which reveals the absence of advanced image enhancement algorithms. It is also a pity that the C6K lacks the feature for smoothing tonal transitions – in older films or video materials, color banding can be noticeable and may be bothersome during long viewing sessions.

This year, the C8 series and higher models have received arguably the largest and most anticipated upgrade in TCL's history, which pertains to digital image processing. The C8L model is the lowest representative in the manufacturer's lineup, equipped with the latest flagship chip MediaTek Pentonic 800 (designated in the menu as MT9655). It is precisely thanks to its computing power that the feature called "Gradual Smoothing" finally works as it should. The algorithm effectively eliminates the unwanted phenomenon of posterization (ugly tonal transitions / color banding) while doing so intelligently, so it does not degrade the sharpness of other details.

The processor also handles upscaling lower resolution materials to 4K very well. Although assessing this element can be purely academic, as the differences between today's televisions in this class are very subtle. The most important piece of information in all of this is that TCL finally has nothing to be ashamed of compared to its competitors.

TCL C6K features a 144 Hz panel, which is a significant advantage in this price range. This is an important step forward compared to the previous model C655 PRO, which offered only 60 Hz at 4K. The difference is especially noticeable when watching sports or playing games – the ball, athletes, or fast action in a game are displayed more clearly and without losing details. An interesting fact is also the ability of the panel to operate at 240 Hz, which the manufacturer does not mention in official materials. We will return to this topic when discussing the game mode for PC.

TCL also added a feature for movie watchers: "Motion Clarity," which allows you to adjust the image to your preferences using two simple sliders. You can keep the movie frame visible or opt for a very smooth, almost theatrical effect. This way, everyone can find settings tailored to their taste.

TCL C8L is equipped with a fast panel featuring a native refresh rate of 144 Hz. This parameter will be appreciated primarily by demanding PC gamers, while most users – relying on consoles or television broadcasts – will utilize a stable 120 Hz. It is indeed at 120Hz that the image processing (in movies/series/sports) is handled by motion algorithms. In the television menu, we will find a tab called "Motion Clarity," which allows you to adjust the smoother according to your own preferences. The algorithms perform well with both cinematic productions at 24 or 30 frames per second and with dynamic sports broadcasts at 50 or 60 frames, ensuring appropriate fluidity.

The TCL C6K is a TV that can confidently be called equipment designed for gamers. Here we have 4K at 144 Hz, VRR support, automatic game mode (ALLM), and Dolby Vision Gaming. Additionally, there's a practical Game Bar, a panel with the most important settings readily available – useful when we want to quickly change something during gameplay (e.g., screen aspect ratio: Yes, that’s possible!). The wide VRR range, reaching up to 240 Hz, deserves attention. However, this is mainly an option for PC gamers who drop below the native 4K resolution. Then the TV can spread its wings and show additional smoothness, especially in fast-paced e-sports titles. In the case of consoles, we stick to the classic limit of 120 Hz, but the possibilities are still quite broad. The only drawback is a slight ghosting that can sometimes be seen in dynamic scenes. Other than that, the C6K offers everything gamers expect from a TV.

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.