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. 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.

And what about HDR? Here, the C6KS performs quite well and – as has become a recurring theme of this review – identically to 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, the video materials look good here. However, one must keep in mind the specifics of the dimming algorithm in this model. When very small, bright points (e.g., stars) appear against a dark background, the television can dim them quite significantly. The goal is simple: to eliminate blooming and maintain the best possible blacks. This is quite a reasonable compromise. Most viewers will definitely appreciate deep, "true black" more than additional micro-details, the display of which could cause the screen to appear greyed out. This is the nature of local dimming technology in this price range, and one must be aware of it. It is also worth noting that the TCL C69KS (C6KS) has an additional PFS coating, which is marketed under the slogan of QLED technology. 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% here.

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.

Unlike the more expensive C6K model, the tested C6KS does not have an option in the menu labelled as Filmmaker Mode. Is this a reason to cry? Absolutely not. Our tests have shown 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 characteristic 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 gives you better colours – the answer is no, in both cases the base is the same and requires slight adjustments.

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, the C69KS's tendency to distort colours has been effectively limited, resulting in a very good final effect. After calibration, we will no longer see excessive warming of scenes in SDR or overly cool tones in HDR. However, it is worth noting the brightness characteristics. In SDR content, it is hard to have any objections – the image looks very good, especially in older films, television programmes, or materials from YouTube. It is significantly more challenging to evaluate the television's performance in HDR. Analysis of the EOTF curve suggests correct behaviour, but its practical variant reveals certain limitations. The C69KS can overly brighten the smallest elements of the frame, while at other times, it can dim the entire scene. Thus, calibration brought clear benefits in terms of colour quality, but certain limitations resulting from the local dimming operation and the way it is controlled by the C69KS cannot be overlooked, as we also saw in the C6K test.

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.

The C69KS handles upscaling quite well. The tested 576p material looks surprisingly decent – a considerable amount of detail is retained, and the algorithm adds a slight "rounding" effect to sharp edges, making the image appear more cohesive. The performance in smoothing tonal transitions is less impressive. The television practically cannot improve them, leaving the image in a rather raw state. With older material, this can be quite tiring, as the lack of additional processing highlights any imperfections.

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.

C69KS offers a simplified motion enhancement panel in films, allowing the adjustment of effect intensity with a slider. This makes it easy to match fluidity to personal preferences. The ability to use higher refresh rates is also a plus – although the panel operates natively at 4K at 60 Hz, lowering the resolution to 1440p enables 120 and 144 Hz modes, both on consoles and PC. This sounds like great news, however, in practice, the image at these settings exhibits significant motion blur. The effect is so pronounced that the overall presentation appears merely average and loses its appeal for everyday use.

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.

If we overlook the smudging and lack of native 4K at 120 Hz, the C69KS impresses with how well it performs during gaming. We get everything one can expect from a gaming television: variable refresh rate (VRR), automatic switching to game mode (ALLM), Dolby Vision Gaming mode, and a well-functioning HGiG. The television can also operate at 120 and even 144 Hz at lower resolutions, allowing for smoother gameplay on a console or PC. Additionally, there is a clear Game Bar that lets you quickly glance at key settings while gaming. As a result — despite a few limitations — the C69KS can be a really successful screen for gamers.