TCL C6K vs Philips OLED811

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.

Philips OLED811 uses a new generation of WOLED EX panels, also found in models such as the LG C6 and Samsung S90H. After calibration we measured around 1500 nits, which is a very good result for an OLED TV. You can see this clearly in films and series. All kinds of bright flashes have the right intensity, especially when they appear against a dark background. In such scenes the OLED811 can deliver truly impressive HDR. Of course, that does not mean you will see that level of brightness in every shot. When the screen is filled with a large amount of white or a wide explosion, brightness falls to around 600 nits. That is still a good result, but those scenes no longer have the same punch as small, bright elements on a dark background. This is a known limitation of OLEDs and the OLED811 is no exception.

Colours

Aside from HDR brightness, colours also matter and here Philips performs very well. It covers almost the entire DCI-P3 gamut, which contains most of the colours used in HDR films and series. You get saturated reds and lush greens, and when watching it’s hard to find major faults in that respect. It looks a little worse with the much wider BT.2020 gamut, whose most saturated shades are already out of reach for this panel. There is also the issue of the white subpixel that the WOLED panel uses to boost brightness. With very bright colours you can see a certain washout: the colour is bright but loses some of its intensity. It is precisely in such situations that QD-OLED panels from Samsung Display have the advantage. However, in most films and series this is not something that will immediately stand out.

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."

Film mode on the Philips OLED811 is sensibly set up straight out of the box. Most colour errors remain small, both in SDR and HDR, so you can sit down to watch without adjusting the settings first. There are no major inaccuracies that would immediately distract from the film. It falls a little short of perfection, though. The white balance shows a slight lack of red compared with green, so whites and greys can have a faint greenish tint. It is not a strong colour cast, but measurements clearly show it. There are also minor brightness deviations in SDR: some parts of the image are slightly brightened, and the darkest shades are not always reproduced evenly. In HDR the TV sticks much closer to the reference, although in places it gently lifts detail from the shadows. These are generally areas that could be improved. The factory film mode provides a good starting point, and calibration will reveal how much more can be gained from it.

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.

After calibration the Philips OLED811 produces an image very close to the reference. We managed to correct the white balance and eliminate the slight tint visible in the factory settings. Errors in the Color Checker measurements for SDR and HDR fell to around 1 to 2, and many samples are even below 1. That's a level at which differences from the reference image are hard to spot with the naked eye. We also improved the gamma, and only in the brightest whites is there a slight brightening remaining. In HDR the EOTF curve also tracks the reference closely, although the TV still tends to gently boost the brightness of small elements, such as stars or on-screen text. This gives the picture a little extra sparkle that shouldn't be there, but otherwise there's little to fault. It was already good out of the box, and after calibration we managed to refine most of the remaining shortcomings.

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.

OLED811 handles lower-quality material reasonably well, though it falls well short of perfection. The "Banding reduction" function helps to smooth tonal transitions and on the low setting gives a fairly good result. It does not remove bands between shades as effectively as similar solutions from some competitors, but at least it does not introduce new artefacts in the process. This is a sensible setting for everyday viewing. There is still some dissatisfaction, however, because the MediaTek Pentonic 800 chipset used here can, in other manufacturers' implementations, cope with the effects of heavy compression more effectively even at similarly low settings. Much therefore depends on how a given manufacturer makes use of its capabilities. We have a few more comments about the upscaling to 4K. There is a lot of detail, but the overall image looks rather soft. Edges are heavily smoothed, which robs the picture of a bit of sharpness and clarity. This can be partly corrected with the sharpness slider in the menu, though that will merely accentuate outlines rather than recover detail. On the plus side, there is no overscan; even with an SD signal the TV does not crop the edges of the picture.

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.

In terms of motion handling the OLED811 performs excellently. At 120 Hz, which is useful for console gaming and watching sport, the picture stays clear and moving objects do not leave noticeable smears. The fast response of OLED pixels helps here; this is clear in the UFO test, even on dark backgrounds. There are also motion smoothing controls. For films you can adjust the level of smoothing to suit your taste, ranging from preserving a cinematic character to much smoother motion. A separate blur reduction setting is useful for fast-paced material such as sports broadcasts.

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.

OLED811 has almost everything you could expect from a TV for gaming. It supports 120 Hz at Full HD, 1440p and 4K, and when connected to a PC it can reach 165 Hz. It also has VRR, which helps prevent screen tearing when frame rates fluctuate, and ALLM, which automatically switches to game mode. So you don't have to dig into the settings every time you power up your console.

Another plus is that HGiG works correctly, so once HDR is set on the console the TV doesn't apply its own changes to image brightness. There's also a Game Bar to check signal parameters and quickly change settings useful while gaming. The list even includes Dolby Vision for gaming, but there is a significant catch, which you can read about below.