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. Such a state of affairs is regularly observed with this brand, so it was not a surprise for us. The first and last scene, which has large light elements, looks phenomenal, "shining" with brightness levels of 1470 and 1820 nits respectively. Such effects will certainly make many people squint, while simultaneously feeling the extraordinary dynamism of the scene itself. You can truly feel as if you were inside the movie. The situation drastically changes when small or minor elements with high luminance surrounded by black appear on the screen. The TCL C855, to avoid the halo effect, significantly reduces brightness to a level of even 240 nits, which is a disappointing outcome, causing the film to not look like it was shot in HDR. The HDR effect in TCL C855 makes watching dynamic scenes more engaging, and the viewer can feel like 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 adapted to scenes with a large amount of detail, increasing viewing comfort.

TCL C6K is a moderately bright television that can showcase its full capabilities in the best movie 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's important to remember that with local dimming management, there are situations where some elements become dimmed, and sometimes even barely visible. It is clear that there is a lack of proper optimization of the algorithms, although looking at the technical parameters in this price range, the build quality performs very well.

The best factory mode for the TCL C855 is "Film," and it is on this mode that we conducted all our tests. However, like every mode predefined by the manufacturer, it had flaws that are worth correcting to achieve an image that is as close as possible to what the film producer intended. We will look at the colour characteristics in both SDR and HDR materials. Taking the former into account, we see a clear dominance of green in the white balance, which, as you might guess, gave an unpleasant greenish tint to the entire image. Examining a very important gamma chart, responsible for the contrast of the image, 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 contrast exaggeration and blending of details into a dark blob. This state of affairs persisted for quite a while, up to 20% of the chart’s value, before then diving below the reference. This, in turn, meant that the image was brightened and contrast decreased significantly. The factory mode performed somewhat better in HDR materials, as the white balance looked quite good, except for the second half, where green again took over. 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, by the way, could be observed in the scene from the film "Pan" in the check paragraph for the TV's HDR.

This year's TCL televisions have introduced the Filmmaker mode, and it must be said that it is definitely the best choice right out of the box. This is the mode we recommend for everyday viewing of movies 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 prominent 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 an excess of blue. There is also the brightness characteristic, which at times led to overexposure. In practice, these issues combined resulted in quite noticeable errors in colour tests, which are hard to accept in a mode advertised as “by the creators”.

TCL, just like the vast majority of manufacturers, provides advanced calibration tools in its televisions. Here we find 2- and 20-point grey scale adjustments 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. It went a bit worse with HDR materials, which the television ChooseTV C855 did not allow us to model properly. We only managed to slightly adjust the EOTF curve and significantly improve the colours themselves.

Thanks to the white balance adjustment, we were able to significantly reduce the C6K's tendency to distort colours, which resulted in a very good end result. After calibration, we won't 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, it's hard to have major objections – the picture looks really good, especially in older movies, TV shows, or material from YouTube. It performs significantly worse with HDR content. An analysis of the EOTF curve suggests that everything is fine, but in practice (EOTF in movies), the limitations of the construction become apparent. The television tends to excessively brighten the smallest fragments of the frame, and in other situations, it can overly dim the entire scene. The effect of calibration is therefore noticeable, and regarding colourimetry, the C6K has really gained a lot, but certain limitations resulting from local dimming and actually from its management by the C6K simply cannot be overlooked.

Once again, we will look at the function of smoothing tonal transitions, but this time also image scaling. The latter is particularly important when watching materials of lower quality, such as some TV programs or older films. We will focus on the function responsible for tonal transitions. Interestingly, just like in the scenes in the previous test, it performed splendidly and smoothed out practically all the choppiness, but here it had problems. Using the menu responsible for the operation of this function, we found that none - not even the strongest - setting helped.

The image scaling in TCL C855 is characterised 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 to our eye. Even small, fine branches do not have jagged contours, and there is no white halo around figures, which is characteristic of weaker scaling systems.

TCL C6K performs quite well in terms of upscaling. Lower quality materials appear acceptable, and the absence of overscan issues means the image is displayed in full, without cropping. However, one cannot expect miracles – very low quality content won't come to life here, as the image processor has its limitations. On thin lines or details, there is characteristic tearing visible, which indicates a lack of advanced image enhancement algorithms. It is also a shame that the C6K lacks the function of smoothing tonal transitions – in older films or video materials, colour banding can be noticeable and may be distracting during longer viewing sessions.

The maximum refresh rate that we can set on TCL C855 is 144 Hz. Naturally, this is only possible when connecting the TCL C855 TV to a very powerful PC. Otherwise, we will operate at a maximum refresh rate of 120 Hz, which is recommended if we primarily want to watch sports or content with a high level of motion dynamics. For those who require high fluidity of image, the manufacturer has implemented a multi-level motion smoother. It has been divided into two separate sliders that adjust the sharpness of moving images (Blur Reduction) and judder (Judder Reduction). Both sliders can be set in the range of 0 to 10, with each level affecting the degree of smoothing, so everyone can find their sweet spot. We present a setting that allows for slight smoothness without the soap opera effect.

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

TCL C6K uses a 144 Hz panel, which is a significant advantage in this price range. It's an important step forward in comparison to the previous model C655 PRO, which only offered 60 Hz in 4K. The difference is especially noticeable when watching sports or playing games – the ball, players, or fast action in the game are displayed more clearly and without losing detail. An interesting fact is the panel's ability to operate at 240 Hz, which the manufacturer doesn't mention in official materials. We will return to this topic when discussing the PC gaming mode.

TCL has also added a feature for movie watchers: "Motion Clarity," which allows users to adjust the image according to their preferences with two simple sliders. You can either keep the visible film frame or opt for a very smooth, almost theatrical effect. This way, everyone can find settings that match their taste.

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

The TCL C855, as one of the first manufacturers, has equipped its televisions with a special GameBar feature that allows extensive setting changes on the fly, without the need to exit the game. It includes functions such as an additional crosshair grid, black level correction, and settings for individuals with disabilities. In the photo, we see the next generation of this solution.

In summary, the TCL C855 television will be an ideal solution for those looking for a screen for any kind of electronic gaming. With all the features supporting such entertainment, it is incredibly engaging. It should also be emphasized that it has very low input lag, regardless of the selected settings, including with the Dolby Vision HDR format.

The TCL C6K is a television that can confidently be called equipment designed for gamers. We have 4K at 144 Hz, VRR support, an automatic gaming mode (ALLM), and Dolby Vision Gaming. On top of that, there's a practical Game Bar, which is a panel with the most important settings handy – useful when we want to quickly change something during gameplay (e.g. screen ratio: Yes, you can!). Notably, it has a wide range of VRR, reaching up to 240 Hz. However, this option is mainly for PC gamers who drop below the native 4K resolution. In that case, the television can spread its wings and show additional smoothness, especially in fast e-sport titles. For consoles, we stick with the classic limit of 120 Hz, but the possibilities are still quite broad. The only slight drawback is some minor motion blur that can occasionally be seen in dynamic scenes. Other than that, the C6K offers everything gamers expect from a television.