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, which allows for a very realistic image. Of course, none of them surpasses the magical thousand, however, the combination of such results along with unlimited contrast and black effectively boosts the visual outcome. The last of the scenes, featuring a fullscreen sun burst, is indeed less bright than the others, although it still represents a respectable level. It's also worth mentioning the excellent coverage of the DCI-P3 colour palette, which will enable the achievement of exceptionally vivid colours.

TCL C6K is a moderately bright television that can showcase its full capabilities in the best movie 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's important to remember that with local dimming management, there are situations where some elements become dimmed, and sometimes even barely visible. It is clear that there is a lack of proper optimization of the algorithms, although looking at the technical parameters in this price range, the build quality performs very well.

The best factory mode implemented in the tested television was "Filmmaker". That was the one we used during all tests. This mode, in terms of colour reproduction, turned out to be quite decent, although other flaws effectively detracted from the enjoyment of the viewing experience. Starting with the most basic one, which is white balance, it was easy to notice that this was marked by a dominance of red, which completely altered the characteristics of the picture. We could see a strong yellowing of the whites and a shift of all colours to warmer tones. The gamma, which is a graph as equally important, if not more so, was quite severely reduced, resulting in a significant drop in contrast, except for the start of the graph, where the television insidiously lost details. That’s all regarding SDR materials. Looking closely at films with a wide dynamic range, we can observe exactly the same phenomenon of white balance yellowing as in films with a standard colour palette. The EOTF curve, which replaces the gamma chart for us, is practically perfect and cannot be faulted.

This year's TCL televisions have introduced the Filmmaker mode, and it must be said that it is definitely the best choice right out of the box. This is the mode we recommend for everyday viewing of movies 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 prominent in the white balance. On the other hand, with HDR content, we had the opposite impression – the image became cooler than it should have been, due to an excess of blue. There is also the brightness characteristic, which at times led to overexposure. In practice, these issues combined resulted in quite noticeable errors in colour tests, which are hard to accept in a mode advertised as “by the creators”.

As we mentioned earlier, LG televisions are equipped with advanced tools for carrying out the calibration process. We used them to model the picture in line with what the director envisioned. And without modesty, we must admit that we achieved this phenomenally. Both SDR and HDR materials present a level that clearly indicates this is how a film should look. It's worth taking a look at the colour errors on the "ColorChecker" palette, where practically none of them exceed "1", except for two samples.

Thanks to the white balance adjustment, we were able to significantly reduce the C6K's tendency to distort colours, which resulted in a very good end result. After calibration, we won't observe the effect of excessive warming of scenes in SDR or overly cooling the image in HDR. However, it is worth taking a closer look at the brightness characteristics. In SDR content, it's hard to have major objections – the picture looks really good, especially in older movies, TV shows, or material from YouTube. It performs significantly worse with HDR content. An analysis of the EOTF curve suggests that everything is fine, but in practice (EOTF in movies), the limitations of the construction become apparent. The television tends to excessively brighten the smallest fragments of the frame, and in other situations, it can overly dim the entire scene. The effect of calibration is therefore noticeable, and regarding colourimetry, the C6K has really gained a lot, but certain limitations resulting from local dimming and actually from its management by the C6K simply cannot be overlooked.

Once again, we will take a look at the feature responsible for gentle gradation, but we will also address the one that aims to enhance the quality of lower-quality materials. The default smoothing of tonal transitions, as we could see, was not the worst, but it can be improved further. The function has a slider that allows us to adjust its intensity. We recommend using the former, as it produces very good results and does not blur important details.

Image scaling on 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. While jagged edges of trees can be seen, it is not a major issue when compared to other manufacturers.

TCL C6K performs quite well in terms of upscaling. Lower quality materials appear acceptable, and the absence of overscan issues means the image is displayed in full, without cropping. However, one cannot expect miracles – very low quality content won't come to life here, as the image processor has its limitations. On thin lines or details, there is characteristic tearing visible, which indicates a lack of advanced image enhancement algorithms. It is also a shame that the C6K lacks the function of smoothing tonal transitions – in older films or video materials, colour banding can be noticeable and may be distracting during longer viewing sessions.

The maximum refresh rate we can set on the LG G4 is 144 Hz. Naturally, this is only possible when connecting the 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 lot of motion dynamics. For those who require high fluidity of the image, the manufacturer has implemented a multi-level 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 in the range of 0 to 10, with each degree affecting the level of smoothing, allowing everyone to find their sweet spot.

The panel of the LG OLED C4 features an average response time of less than 1 ms (which directly results from our measurements), enabling the achievement of an extremely clear image, unattainable for LCD TVs, which can have response times of up to several milliseconds. This is clearly evident in the images from the "UFO Test," which show no trailing blur behind the object.

TCL C6K uses a 144 Hz panel, which is a significant advantage in this price range. It's an important step forward in comparison to the previous model C655 PRO, which only offered 60 Hz in 4K. The difference is especially noticeable when watching sports or playing games – the ball, players, or fast action in the game are displayed more clearly and without losing detail. An interesting fact is the panel's ability to operate at 240 Hz, which the manufacturer doesn't mention in official materials. We will return to this topic when discussing the PC gaming mode.

TCL has also added a feature for movie watchers: "Motion Clarity," which allows users to adjust the image according to their preferences with two simple sliders. You can either keep the visible film frame or opt for a very smooth, almost theatrical effect. This way, everyone can find settings that match their taste.

We can now say that LG C4, like practically every OLED television from the manufacturer, is exceptionally good in terms of cooperation with consoles and PCs. Thanks to the implementation of four full-bandwidth HDMI 2.1 ports at 48 Gbps, the manufacturer has embedded all the features that enhance gaming comfort, including simultaneous support for FreeSync and G-Sync technologies. With such a tandem, players with graphics cards from AMD or nVidia can safely choose C4. However, what should please gamers demanding the highest possible quality the most is the simultaneous implementation of HDR Dolby Vision and HGIG mode. The former is particularly important as it operates with extremely low input lag in all settings.

A standard feature in televisions from the Korean manufacturer is also the implementation of GameBar, allowing for quick adjustments of settings "on the fly," without the need to exit the game. It also allows for image adjustments for people with visual impairments, which is an incredibly nice touch. Another important piece of information is that when VRR technology is enabled, we won’t experience a drop in contrast. This is, of course, due to the design of the panel and the absence of conventional backlighting. It is, however, 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 the manufacturer's OLEDs equipped with high-refresh-rate panels and HDMI 2.1 connections, creates a harmonious whole with consoles. In practice, it is a complete television, and if we expect the highest possible efficiency in gaming, C4 will be an ideal choice.

The TCL C6K is a television that can confidently be called equipment designed for gamers. We have 4K at 144 Hz, VRR support, an automatic gaming mode (ALLM), and Dolby Vision Gaming. On top of that, there's a practical Game Bar, which is a panel with the most important settings handy – useful when we want to quickly change something during gameplay (e.g. screen ratio: Yes, you can!). Notably, it has a wide range of VRR, reaching up to 240 Hz. However, this option is mainly for PC gamers who drop below the native 4K resolution. In that case, the television can spread its wings and show additional smoothness, especially in fast e-sport titles. For consoles, we stick with the classic limit of 120 Hz, but the possibilities are still quite broad. The only slight drawback is some minor motion blur that can occasionally be seen in dynamic scenes. Other than that, the C6K offers everything gamers expect from a television.