LG OLED C4 vs TCL C6K

The results of HDR materials are definitely among the better ones. Practically every film significantly exceeds the 700 nits barrier, allowing for a very realistic image. Of course, none of them surpasses the magical thousand, yet the combination of such results and unlimited contrast and black effectively boosts the outcome optically. The last of the scenes, featuring a full-screen burst of sunlight, is actually less bright than the others, although it still represents a commendable level. It is also worth mentioning the excellent coverage of the DCI-P3 colour palette, which will allow for achieving extremely vivid colours.

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.

The best factory mode implemented in the tested television was "Filmmaker". It was this mode that we used during all tests. This mode proved to be quite good in terms of colour reproduction; however, other shortcomings effectively detracted from the enjoyment of viewing. Starting with the most basic aspect, the white balance, it was easy to notice that it was marked by a dominance of red, which overall changed the characteristics of the image. We could thus see a strong yellowing of the whites and a shift of all colours towards warmer shades. The gamma, which is a curve just as important, if not more so, was quite significantly lowered, resulting in a considerable drop in contrast, except at the beginning of the graph, where the television insidiously lost details. That’s all regarding SDR materials. Taking a closer look at films with a wide dynamic range, we can observe exactly the same phenomenon of yellowing of the white balance as in films with a standard colour palette. The EOTF curve, which replaces our gamma curve, is practically perfect and cannot be faulted.

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."

As we mentioned earlier, LG televisions are equipped with advanced tools for carrying out the calibration process. We therefore used them to model the image in the way that the director intended. And without modesty, we must admit that we achieved this phenomenally. Both SDR and HDR materials present a level that clearly indicates that this is how a film should look. It is worth looking at the colour errors on the "ColorChecker" palette here, where practically none of them exceeds "1", apart from two samples.

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.

Once again, we will take a look at the function responsible for smooth gradation, but we will also address the one that aims to improve the quality of lower-quality materials. The default smoothing of tonal transitions, as we have seen, was not the worst, but it can still be improved. The function has a slider, which allows us to adjust its strength. We recommend using the first one, as it yields very good results and does not blur important details.

Image scaling in LG C4 is quite good; however, it cannot be said to be without flaws. The image is slightly sharper by default, although not in a very noticeable way. Admittedly, there are jagged edges on the trees, but this is not a major issue compared to other manufacturers.

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.

The maximum refresh rate that we can set on the LG G4 is 144 Hz. Naturally, this is only possible when connecting the television to a very powerful PC. In other cases, we will be operating at a maximum refresh rate of 120 Hz, which is recommended if we primarily want to watch sport or content with a lot of motion dynamics. For those requiring high fluidity of the image, the manufacturer has implemented a multi-step motion smoother called "TrueMotion". It has been divided into two separate sliders that adjust the sharpness of moving images (De-Blur) and judder (De-Judder). Both sliders can be set within a range from 0 to 10, with each degree affecting the degree of smoothing, allowing everyone to find their golden mean.

The LG OLED C4 panel features an average response time of less than 1 ms (which directly results from our measurements), allowing for an incredibly clear image that is unattainable for LCD televisions, whose response times can be as high as several milliseconds. This is clearly visible in the pictures from the "UFO Test," showing no trailing blur behind the object.

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.

We can already say that LG C4, like practically every OLED television from the manufacturer, is exceptionally good in terms of compatibility with consoles and PCs. Thanks to the implementation of four full bandwidth HDMI 2.1 ports at 48 Gbps, the manufacturer has included all features that enhance the gaming experience, among which we find simultaneous support for FreeSync and G-Sync technology. With such a tandem, gamers with a graphics card from AMD or Nvidia can confidently opt for C4. However, what should delight the players requiring the highest possible quality the most is the simultaneous implementation of HDR Dolby Vision and HGIG mode. The first is particularly important as it works with extremely low input lag in all settings.

A standard in the Korean manufacturer's televisions is also the implementation of GameBar, allowing for quick adjustments of settings "on the fly" without the need to exit the game. It also enables image adjustments for visually impaired individuals, which is a very nice touch. Another important piece of information is that when VRR technology is enabled, we will not experience a drop in contrast. This is, of course, due to the panel's design and the absence of conventional backlighting. However, it is normal for shades of grey to flicker slightly, although this is a characteristic feature of this function regardless of the manufacturer and television.

In summary: LG C4, just like all of the manufacturer's OLEDs equipped with high refresh rate panels and HDMI 2.1 ports, creates a harmonious whole with consoles. In practice, it is a complete television, and if we expect the highest possible performance in gaming, C4 will be an ideal choice.

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.