TCL C855 vs TCL C6KS / C69KS / Q6CS

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.

And what about HDR? Here the C6KS performs quite well and – as is becoming the theme of this review – just like in the C6K model. The maximum brightness generated by this television is around 600 nits. In bright scenes, this translates to a really solid, cinematic effect and generally, video materials look good here. However, it's important to keep in mind the specifics of the dimming algorithm in this model. When very small, bright points (e.g. stars) appear on a dark background, the television can quite significantly dim them. The goal is simple: to eliminate blooming and maintain the best possible black. It's a reasonable compromise. Most viewers will definitely appreciate deep, “true black” more than additional microscopic details, the display of which could cause the screen to appear greyed out. Such is the nature of local dimming technology in this price range, and one must be aware of this. It’s also worth noting that the TCL C69KS (C6KS) has an additional PFS coating, which is marketed under the QLED technology slogan. Thanks to this, the colours are saturated and vibrant – our measurements showed that the coverage of a wide colour gamut reaches as much as 92%.

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.

In contrast to the more expensive C6K model, in the tested C6KS we don't find an option in the menu labelled as Filmmaker Mode. Is this a reason to cry? Absolutely not. Our tests showed that in practice, in terms of colour reproduction, the lack of this specific label makes virtually no difference. The best available Film/Cinema mode here offers an almost identical picture profile to the aforementioned Filmmaker in the more expensive model. So we get a very similar image, just under a different name. Therefore, if you were wondering whether paying extra for the C6K would give you better colours – the answer is: no, in both cases the base is the same and requires slight adjustments.

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, the C69KS's tendency to distort colours has been effectively limited, leading to a very good final effect. After calibration, we will no longer see excessive warmth in SDR scenes or overly cool tones in HDR. However, it is worth noting the brightness characteristic. In SDR content, there are hardly any objections – the image looks very good, especially in older films, TV shows, or YouTube materials. Evaluating the television's performance in HDR is much more difficult. Analysis of the EOTF curve suggests correct behaviour, but its practical variant shows certain limitations. The C69KS can overly brighten the smallest elements of the frame, while at other times it can dim the entire scene. Calibration has therefore brought clear benefits in terms of colour, but certain limitations resulting from local dimming and the way it is controlled by the C69KS cannot be avoided, which we also observed in the C6K test.

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.

The C69KS handles upscaling quite well. The tested 576p content looks surprisingly decent – a considerable amount of detail is preserved, and the algorithm adds a subtle ‘rounding’ effect to sharp edges, making the image appear more cohesive. However, it doesn't perform as well when it comes to smoothing tonal transitions. The television practically cannot improve them, leaving the image in a rather raw state. With older materials, this can be simply exhausting, as the lack of additional processing highlights all imperfections.

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.

C69KS offers a simplified motion enhancement panel in movies, allowing users to adjust the intensity of the effect using a slider. This makes it easy to tailor the smoothness to personal preferences. It also deserves credit for the ability to utilise higher refresh rates – even though the panel operates natively in 4K at 60 Hz, by lowering the resolution to 1440p, modes of 120 and 144 Hz can be enabled, on both consoles and PC. This sounds like great news, however, in practice, the image at these settings trails exceptionally badly. The effect is so pronounced that the overall experience simply appears mediocre and loses its appeal in everyday use.

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.

If we overlook the smudging and lack of native 4K at 120 Hz, the C69KS is impressive in how well it performs for gaming. You get everything you would expect from a gaming TV: Variable Refresh Rate (VRR), Auto Low Latency Mode (ALLM), Dolby Vision Gaming mode, and a consistently functioning HGiG. The TV can also operate at 120 or even 144 Hz at lower resolutions, making gameplay on console or PC smoother. Additionally, there's a clear Game Bar that allows you to quickly check key settings while gaming. As a result — despite a few limitations — the C69KS can be a genuinely successful screen for gamers.