LG OLED C4 vs TCL C6K

The HDR performance of the LG OLED C4 is impressive, firmly placing it in the higher tier. Most films exceed 700 nits, delivering a highly realistic image. While none surpass the 1,000-nit mark, the combination of these results with the TV’s infinite contrast and perfect blacks significantly enhances the visual experience. The final scene, with a full-screen flash of sunlight, is slightly less bright than the others but still maintains a solid level of brightness. Another highlight is the excellent DCI-P3 colour gamut coverage, which ensures incredibly vibrant colours. The HDR technology in the LG OLED C4 delivers exceptional colour and detail reproduction. The dynamic tone mapping feature optimises brightness levels, ensuring ideal light reproduction in every scene, even in the most demanding high-dynamic films.

TCL C6K is a moderately bright TV 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 really satisfying, providing a sense of cinematic brilliance. However, it should be noted that when managing the backlighting zones, there are situations where some elements become dimmed and sometimes can even become barely visible. It is clear that there is a lack of proper algorithm optimization here, although looking at the technical parameters in this price range, the design itself performs very well.

The best factory mode on the tested television was "Filmmaker," which served as the basis for all evaluations. In terms of colour reproduction, this mode performed reasonably well; however, certain flaws significantly detracted from the overall viewing experience. The most fundamental issue was the white balance, which exhibited a noticeable dominance of red, skewing the image characteristics. This resulted in a pronounced yellow tint to whites and a general shift of all colours towards warmer tones.

The gamma, an equally crucial—if not more important—aspect, was notably lowered, leading to a marked reduction in contrast. Additionally, the television frequently lost detail at the start of the gamma curve. These issues were most apparent in SDR content.

When examining HDR materials, the same yellowing effect in the white balance was observed, as seen with SDR content. However, the EOTF curve, which replaces the gamma curve for HDR, was near perfect and left little room for criticism.

This year's TCL televisions feature a Filmmaker mode, and it must be admitted that it is definitely the best choice straight out of the box. This is the mode we recommend for everyday watching of movies and series. Unfortunately, as is often the case, the best doesn't mean perfect. In the case of SDR content, the image was too warm because the red was strongly emphasized 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 excess blue. Additionally, the brightness characteristic sometimes led to highlights being blown out. In practice, this resulted in quite noticeable color test inaccuracies that are hard to accept in a mode advertised as "by the creators."

As mentioned, LG televisions come with advanced tools to facilitate an accurate calibration process. By utilising these tools, we meticulously adjusted the image to align with the director’s original vision. Without overstating, the results were outstanding. Both SDR and HDR content now achieve a level of visual fidelity that reflects how films are intended to be seen.

Examining the colour accuracy on the "ColourChecker" palette reveals impressive results, with almost all colour errors falling below a delta of "1," aside from two minor exceptions. Post-calibration, the LG OLED C4 demonstrated a marked improvement in colour reproduction, particularly in SDR and HDR modes. Testing the TV after calibration highlighted its capacity for delivering exceptionally accurate colours, underlining the high calibre of this model. The LG C41LA offers a stunningly precise colour palette, sure to satisfy even the most discerning viewers.

Thanks to the white balance correction, it was possible to significantly reduce the C6K's tendency to distort colors, which resulted in a very good final outcome. After calibration, we will no longer 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, there are few complaints – the image looks really good, especially in older movies, TV shows, or materials from YouTube. This is much worse for HDR content. Analysis of the EOTF curve suggests that everything is fine, but in practice (EOTF in films), the limitations of the construction become apparent. The TV tends to overly brighten the smallest parts of the frame, and in other situations, it can dim the entire scene too much. The effect of calibration is therefore evident, and in terms of color, the C6K has gained quite a lot, but certain limitations arising from local dimming and, in fact, its management by the C6K simply cannot be overcome.

Let us revisit the function responsible for smooth gradation and consider its role in improving lower-quality materials. The default smoothing of tonal transitions, while decent, can be further enhanced. The feature includes a slider for adjusting its strength, and we recommend selecting the first option. This setting strikes a balance, offering excellent results without compromising important details through unnecessary blurring.

The image scaling on the LG C4 is commendable, though not entirely without flaws. By default, the image appears slightly sharper, though not to an intrusive degree. While jagged edges on elements like trees are occasionally visible, this issue is relatively minor compared to similar offerings from other manufacturers.

The TCL C6K performs quite well in terms of scaling. Lower quality materials look acceptable, and the lack of overscan issues means that the image is displayed in full, without cropping. However, one cannot expect miracles – content of very low quality will not gain new life here, as the image processor has its limitations. On thin lines or details, the characteristic tearing is visible, which reveals the absence 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, color banding can be noticeable and may be bothersome during long viewing sessions.

The LG G4 supports a maximum refresh rate of 144 Hz, achievable only when connected to a high-performance PC. Otherwise, the television operates at a maximum of 120 Hz, the recommended setting for viewing sports or content with fast-paced motion. For those prioritising smooth image quality, LG has included a versatile motion smoothing feature called "TrueMotion." This function is split into two adjustable sliders: De-Blur, which sharpens moving images, and De-Judder, which reduces jitter. Both sliders offer a range of settings from 0 to 10, enabling users to fine-tune the motion smoothness to their preference.

The LG OLED C4 boasts an impressive average response time of less than 1 millisecond, as confirmed by our measurements. This results in exceptional image clarity, far surpassing LCD televisions, which often have response times of several milliseconds. This clarity is evident in tests like the "UFO Test," where no trailing blur is visible behind moving objects.

TCL C6K features a 144 Hz panel, which is a significant advantage in this price range. This is an important step forward compared to the previous model C655 PRO, which offered only 60 Hz at 4K. The difference is especially noticeable when watching sports or playing games – the ball, athletes, or fast action in a game are displayed more clearly and without losing details. An interesting fact is also the ability of the panel to operate at 240 Hz, which the manufacturer does not mention in official materials. We will return to this topic when discussing the game mode for PC.

TCL also added a feature for movie watchers: "Motion Clarity," which allows you to adjust the image to your preferences using two simple sliders. You can keep the movie frame visible or opt for a very smooth, almost theatrical effect. This way, everyone can find settings tailored to their taste.

The LG C4, like nearly all OLED televisions from the manufacturer, excels in its compatibility with consoles and PCs. With the inclusion of four full-bandwidth HDMI 2.1 ports supporting 48 Gbps, the TV incorporates a range of features to enhance the gaming experience. Notably, it offers simultaneous support for FreeSync and G-Sync, making it an ideal choice for gamers using AMD or Nvidia graphics cards. For those seeking the best possible gaming quality, the integration of HDR Dolby Vision and HGIG mode is particularly impressive. HDR Dolby Vision operates with remarkably low input lag across all settings, ensuring smooth and responsive gameplay.

A standout feature in LG's televisions is the GameBar, which allows users to adjust settings in real-time without leaving the game. This includes options for customising the image for viewers with visual impairments, a thoughtful addition. Additionally, enabling VRR (Variable Refresh Rate) does not result in a loss of contrast—a benefit of the OLED panel's self-emissive technology, eliminating the need for conventional backlighting. While some slight flickering of grey tones may occur, this is a characteristic of VRR technology across all manufacturers.

In summary: The LG C4, like the brand's other OLED models equipped with high-refresh-rate panels and HDMI 2.1, provides a seamless and immersive gaming experience. For gamers demanding top-tier performance, this TV is an outstanding choice.

The TCL C6K is a TV that can confidently be called equipment designed for gamers. Here we have 4K at 144 Hz, VRR support, automatic game mode (ALLM), and Dolby Vision Gaming. Additionally, there's a practical Game Bar, a panel with the most important settings readily available – useful when we want to quickly change something during gameplay (e.g., screen aspect ratio: Yes, that’s possible!). The wide VRR range, reaching up to 240 Hz, deserves attention. However, this is mainly an option for PC gamers who drop below the native 4K resolution. Then the TV can spread its wings and show additional smoothness, especially in fast-paced e-sports titles. In the case of consoles, we stick to the classic limit of 120 Hz, but the possibilities are still quite broad. The only drawback is a slight ghosting that can sometimes be seen in dynamic scenes. Other than that, the C6K offers everything gamers expect from a TV.