TCL C6K vs Philips OLED820

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.

When it comes to HDR quality, the Philips OLED820 uses the same class of WOLED panel found in its biggest rivals – the LG C5 and Samsung S90F. This means we can expect really solid results. This year, mid-range OLED panels can exceed the threshold of a thousand nits, and the tested model reaches around 1300 nits in some films. This is an outstanding result, allowing the director's vision to be conveyed with immense precision, as this is the brightness range in which contemporary productions are mastered. Of course, there are situations where even the OLED820 has to compromise. Full-screen scenes filled with white, like those in the film The Meg, can drop brightness to 400–500 nits, which clearly weakens the effect. This is a characteristic of OLED technology that has yet to be fully eliminated. Despite this limitation, it is hard not to appreciate the HDR in this model – high luminance and a wide DCI-P3 colour gamut coverage of 99% make the image simply look fantastic.

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."

The colour reproduction in the factory settings really surprised us, and positively so. The Philips OLED820, switched to Filmmaker mode, immediately showed that it was quite well tuned in terms of colour. The white balance was relatively accurate, though there was a slight deficiency in the blue hue, which occasionally gave the image a slightly yellowish tint. However, this is not a flaw that particularly detracts from everyday viewing. A bigger issue arose with the brightness characteristics. The gamma curve clearly deviated from the ideal, with the line below the expected values, causing the image to be excessively brightened, and the colours looked as if they were covered with a light milky filter. This effect was also noticeable in tests using the Colour Checker pattern, where more pronounced errors appeared.

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, both the Filmmaker mode and the gaming mode gained a lot. A slight adjustment of the white balance and an improvement in brightness characteristics produced excellent results in SDR content – the image looked almost perfect, natural, and very close to reference. In the case of HDR materials, the situation was similar, the colours were presented wonderfully, and it was hard to find anything to criticise. However, we noticed a certain feature, which we already pointed out when comparing scenes from the film Billy Lynn. The analysis of the EOTF curve showed that the television has a slight tendency to dim details in the blacks, so the darkest parts are not always displayed exactly as intended by the director. Nevertheless, the effect after calibration is stunning, and the OLED820 is emerging as one of the more interesting screens in its class. It just needs a little pampering, and there really is nothing to worry about.

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.

Fortunately, the earlier effects of the mentioned posterisation can be quite effectively mitigated. The "distortion reduction" function set to a medium level deals with unwanted colour banding, improving the smoothness of tonal transitions. It does happen that it works a bit too aggressively and also smooths out some details – such as minor skin imperfections of the actors – but nevertheless, it can be considered worth using without substantial compromises. The upscaling in the OLED820 also performs quite well. The test image with the model is exceptionally soft, sometimes even too much so, although this can be rectified by slightly boosting the sharpness in the picture menu – this is really a matter of individual preference. The absence of overscan issues with very low-resolution content is also commendable, meaning we don't have to worry that the image will be unnecessarily cropped.

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 fluidity of motion is an area where OLEDs always shine, and the Philips OLED820 confirms this rule. The panel itself offers a refresh rate of 144 Hz, which primarily benefits PC gamers, but even with standard television sources or consoles, where it operates at 120 Hz, the motion is fast, sharp and simultaneously smooth, without signs of blurring. This is thanks to the remarkable response time between pixels, which maintains image clarity in every dynamic scene. The manufacturer has also added its own smoother called "Motion Style". In the menu, we find two sliders – the first, responsible for fluidity, allows adjustments to the number of artificially added frames in films. This way, we can choose a raw, cinematic character with a distinctly visible film frame or a more theatrical image with smooth motion. The second slider is for motion blur reduction, particularly useful in sports broadcasts. Here, we definitely recommend setting it to the maximum value, as the effect is truly excellent.

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.

The Philips OLED820 is one of the most complete televisions for gamers. On board, we find practically everything one could expect: two HDMI 2.1 ports with full bandwidth of 48 Gbps (it's a shame there aren't four), variable refresh rate VRR, automatic game mode ALLM, support for Dolby Vision in games, and a good implementation of the HGiG mode. The television handles lower resolutions at 120 Hz with ease, so one can count on considerable flexibility when choosing different picture modes on the console. Philips also includes a Game Bar – a panel that allows changing picture modes, adding a crosshair, or previewing parameters. Although it looks rather clunky and is less polished than that of the competition, it does its job. In practice, therefore, the OLED820, in addition to a full set of four HDMI 2.1 ports, offers nearly everything a gamer could need.