TCL C6K vs TCL C8L / QM8L

TCL C6K is a moderately bright television 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 truly satisfying, providing a sense of cinematic sparkle. However, it is important to remember that when managing backlight zones, there are occasions where some elements are dimmed, and at times become barely visible. It is clear that there is a lack of proper algorithm optimisation here, although looking at the technical parameters in this price range, the overall construction performs exceedingly well.

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.

In this year's TCL televisions, the Filmmaker mode has appeared, and it must be admitted that it is definitely the best choice straight out of the box. This is the mode we recommend for daily watching of films and series. Unfortunately, as is often the case, the best does not mean perfect. In the case of SDR content, the image was too warm, as the red was quite pronounced in the white balance. Conversely, with HDR content, we had the opposite impression – the image became cooler than it should have been due to an excess of blue. Additionally, the brightness characteristics sometimes led to overexposure. In practice, this resulted in quite noticeable errors in colour tests, which are difficult to accept in a mode advertised as "from 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 referring to Filmmaker Mode, which has only recently been introduced in the software structures of this brand (a year ago in the "K" series). Thanks to it, the average user can achieve quite a decent colour reproduction straight out of the box, although it is definitely not a mode that is perfectly tuned. Just looking at the factory white balance of our model – both in SDR and HDR content – there was clearly a deficiency in the red component, causing the image to be noticeably cooler and slightly veering 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, the situation in HDR is considerably worse. Tracking the EOTF curve clearly shows that the television has a significantly boosted brightness across the entire range, which can result in the final image being excessively bright and inconsistent with the intentions of the creators – and this happens in a mode that, by definition, should avoid that. Of course, like every unit in our laboratory, this one was also subjected to professional calibration, and its results can be found below.

Thanks to the white balance adjustment, it was possible to significantly reduce the C6K's tendency to distort colours, which translated into a very good final result. After calibration, we will no longer observe the effect of excessive warmth in SDR scenes or overly cooling the image in HDR. However, it is worth taking a closer look at the brightness characteristics. In SDR content, it is difficult to have major objections – the image looks really good, especially in older films, television programmes, or materials from YouTube. It fares much worse in the case of HDR content. An analysis of the EOTF curve suggests that everything is fine, but in practice (EOTF in films), the limitations of the design become apparent. The television tends to over-brighten the smallest parts of the frame, and in other situations, it can dim an entire scene too much. The effect of calibration is therefore evident, and in terms of colour, the C6K has gained quite a lot, but certain limitations arising from local dimming and, in fact, from 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 advanced adjustment tools that the manufacturer has made available to us in the menu. Firstly, we managed to completely correct the white balance – we eliminated the red deficiency, which finally stopped the image from drifting into undesirable, cool hues. After this adjustment, the errors in the ColorChecker test dropped to near-reference values, consistently falling below the Delta E threshold of 2, which is below the perceptibility limit for the human eye.

Since the test patterns are so ideal, you might ask us: why then a lower final score in this category? The answer lies in the brightness management described earlier. Although the menu features sliders that allow for precise adjustment of the EOTF curve on synthetic signals, when confronted with actual film material (I recommend enabling the EOTF filter in films now), it is evident that the television reacts to HDR metadata in its own way in most scenarios. As a result, the image can sometimes appear slightly overexposed and not in line with the creators' intent – and it is precisely for this lack of consistency in real films that we had to deduct a few points from the C8L model.

TCL C6K performs quite well in terms of scaling. Lower quality materials look acceptable, and the absence of overscan issues means that the image is displayed in full, without cropping. However, one cannot expect miracles – very low-quality content will not gain a new life here, as the image processor has its limitations. On thin lines or details, there is a noticeable characteristic jerking, which reveals the lack 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, colour banding can be noticeable and can be distracting during longer viewing sessions.

This year, the C8 series and higher models have received probably the biggest and most anticipated upgrade in TCL's history, which pertains to digital image processing. The C8L model is the entry-level representative in the manufacturer's offering, equipped with the latest flagship chip MediaTek Pentonic 800 (marked in the menu as MT9655). Thanks to its computing power, the feature called "Gradual Smoothing" finally works as it should. The algorithm effectively eliminates the unwanted phenomenon of posterisation (ugly tonal transitions / banding of colours), doing so intelligently enough not to degrade the sharpness of other details.

The processor also excels at upscaling lower resolution content to 4K. Although the assessment of this element can be purely academic, as the differences between today's televisions in this class are very subtle. The most important information in all of this is that TCL finally has nothing to be ashamed of compared to the competition.

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

TCL has also added a feature for those watching films: "Motion Clarity", which allows users to adjust the image to their liking using two simple sliders. One can either keep the film frame visible or opt for a very smooth, almost theatrical effect. This way, everyone can find settings tailored to their taste.

TCL C8L has been equipped with a fast panel with a native refresh rate of 144 Hz. Such a specification will be appreciated primarily by demanding PC gamers, while most users – relying on consoles or television broadcasts – will benefit from a stable 120 Hz. It is indeed at 120Hz that the motion algorithms are responsible for image processing (in films/series/sports). In the television's menu, we will find the "Motion Clarity" tab, which allows you to adjust the smoothness according to your own preferences. The algorithms perform well with both cinema 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 television that can confidently be described as equipment designed with gamers in mind. Here we have 4K at 144 Hz, VRR support, automatic game mode (ALLM), and Dolby Vision Gaming. Additionally, there is a practical Game Bar, which is a panel with the most important settings easily accessible – useful when we want to quickly change something during gameplay (e.g. screen aspect ratio: Yes, it can be done!). The wide range of VRR is also noteworthy, reaching up to 240 Hz. However, this option is primarily for PC gamers who will drop the resolution below native 4K. At that point, the television can spread its wings and demonstrate extra fluidity, especially in fast-paced esports titles. In the case of consoles, we stick to the classic limit of 120 Hz, but the possibilities are still really broad. The only drawback might be slight ghosting, which can sometimes be seen in dynamic scenes. Apart from that, though, the C6K offers everything that gamers expect from a television.

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.