TCL C855 vs TCL C6K

TCL C855 delivers a highly varied HDR effect. On one hand, the television truly shines, while on the other, it resembles a lower model with FALD backlighting. This situation is, however, regularly observed in this brand, so it was not a surprise to us. The first and last scenes, featuring large elements of light, look almost phenomenal, "shining" with brightness levels of 1470 and 1820 nits respectively. Such effects will certainly cause more than one person to squint, while simultaneously feeling the extraordinary dynamism of the scene itself. You can truly feel as if you are inside the film. The situation changes dramatically when small or minor elements with high luminance surrounded by black appear on the screen. The TCL C855, in order to avoid the halo effect, significantly reduces brightness to a level of even 240 nits, which is a disappointing result, causing the film to not appear as if it was recorded in HDR. The HDR effect in the TCL C855 makes watching dynamic scenes more engaging, allowing the viewer to feel as though they are part of the action. Even with smaller elements of high luminance, the television manages to maintain details without excessive dimming. Moreover, the TCL C855 test shows that the brightness of the image is adjusted for scenes with a large amount of detail, which enhances viewing comfort.

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.

The best factory mode for the TCL C855 is "Film," and it is on this mode that we conducted all our tests. Like any mode predefined by the manufacturer, it had its drawbacks that are worth correcting to achieve an image as close as possible to what the film producer intended. We will examine the colour characteristics in both SDR and HDR materials. Looking at the first, we see a noticeable dominance of green in the white balance, which, as you might imagine, resulted in an unpleasant greenish tint across the entire image. Observing the very important gamma chart, which is responsible for the image's contrast, we see a significant deviation from the reference line marked at 2.4. From the left, we can observe a strong spike in the measured value, which at this point caused the image to be overly contrasted, merging details into a dark blob. This situation persisted for quite some time, up to 20% of the chart's value, before then dipping below the reference. This, in turn, meant a brightening of the image and a significant drop in contrast. The factory mode performed slightly better in HDR materials, as the white balance looked quite good, except for the second half, where green once again took precedence. Looking at the EOTF curve, which, unlike gamma, shows the rate of brightness increase, we see primarily two errors: the darkest scenes were too dark, and the brightest ones were overexposed. This was something we could also observe in the scene from the film "Pan" in the paragraph checking the TV's HDR.

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."

TCL, like the vast majority of manufacturers, provides advanced calibration tools in its televisions. Here we find 2- and 20-point adjustments for greyscale as well as an advanced colour management system. The results, as you can see, are very good, and in SDR materials we have significantly approached the reference image. We eliminated both the green tint and the gamma issue, although there is still a slight "kink" at the very beginning. The performance with HDR materials was somewhat poorer, as the TCL C855 did not allow us to model them adequately. We were only able to slightly adjust the EOTF curve and significantly improve the colours themselves.

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.

Once again, we will take a look at the function of smoothing tonal transitions, but this time also at image scaling. The latter is particularly important when watching lower-quality materials, such as certain television programmes or older films. We will focus on the function responsible for tonal transitions. Interestingly, just like in the scenes of the previous test, it performed excellently and smoothed out practically all the inconsistencies; however, here it had problems. Using the menu responsible for this function, we found that no setting - even the strongest - was of any help.

Image scaling in TCL C855 is described as one of the best we have had the opportunity to test so far. The image is sharp, but in a way that could be described as natural for our eyes. Even the small, fine branches do not have jagged edges, and there is no white halo around figures, which is characteristic of inferior scaling systems.

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.

The maximum refresh rate we can set on the TCL C855 is 144 Hz. Naturally, this is only possible by connecting the TCL C855 television to a very powerful PC. Otherwise, we will be operating at a maximum refresh rate of 120 Hz, which is recommended if we primarily want to watch sports or content with a lot of motion dynamics. For those requiring high image fluidity, the manufacturer has implemented a multi-stage motion smoother. This has been divided into two separate sliders regulating the sharpness of moving images (Motion Blur Reduction) and flicker (Flicker Reduction). Both sliders can be set in the range from 0 to 10, with each increment affecting the level of smoothing, so everyone can find their sweet spot. We present a setting that allows for slight smoothing without the soap opera effect.

The panel of the TCL C855 features a very good response time. This is particularly important as VA panels often have issues with so-called ghosting, which is the effect where a black halo can be seen behind a fast-moving object.

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.

The TCL C855 television is equipped with full HDMI 2.1 connectors with a full bandwidth of 48 Gb/s. During our tests, we confirmed the seamless operation of all functions that are part of this standard. As can be seen, all checkboxes light up green, which will certainly be appreciated by gamers, both console and those using the television as a monitor for their computer. Additionally, the TCL C855 supports both AMD FreeSync and NVIDIA's G-Sync, which can be easily activated in the graphics card settings. Those with a very powerful setup can send a 144 Hz signal to the C855, which this television handles effortlessly. It is also worth mentioning the implementation of the HGIG mode, which, however, due to the flaw of the “Game” mode, is overly brightened, making it difficult to configure properly on screen. Fortunately, the television performs excellently with the Dolby Vision format.

The TCL C855 is one of the first manufacturers to equip its televisions with a special GameBar, which allows for extensive setting changes on the fly, without the need to exit the game. It features functions such as an additional crosshair grid, black level correction, and settings for people with disabilities. In the picture, we can see the next generation of this solution.

In summary, the TCL C855 television will be an ideal solution for those seeking a screen for all sorts of electronic gaming. Thanks to all the features supporting such entertainment, it is incredibly engaging. It is also important to highlight the very low input lag, regardless of the selected settings, including with the HDR Dolby Vision format.

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.