Samsung OLED S90D / S94D (WRGB OLED) vs TCL C6K

The Samsung S90D demonstrates impressive brightness performance in the tested film scenes, surpassing the 1000 nits mark in the first four shots—an outstanding result for an OLED display. In the final shot, which features a fullscreen flash of sunlight, the brightness dips to around 500 nits. While this is a decrease, it remains within a very good range, ensuring visibility and detail retention even in bright scenes.

Another key highlight of the Samsung S90D is its remarkable colour coverage, achieving 98% of the DCI-P3 colour space. This means the TV can reproduce an exceptionally wide range of colours, contributing to vivid and lifelike images that are particularly beneficial for films, high-quality video, and HDR content. The high colour accuracy and impressive brightness capabilities, makes the S90D an ideal choice for users seeking premium image quality across various lighting environments, whether in darker rooms or bright, sunlit spaces.

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 S90D was tested in Filmmaker mode, which provides good colour reproduction, albeit with some imperfections that may be noticeable to more discerning users. This mode might appear overly warm, and those switching from Standard mode could find the change somewhat jarring. It is important to note that this issue stems from suboptimal settings, such as the white balance, rather than the Filmmaker mode.

In both SDR and HDR content, the device shows a drop in blue tones, resulting in colours appearing warmer than intended. In practice, this means that certain shades, such as sky blue or skin tones, may seem less natural, with a slight pink or yellow tint. The Colour Checker test confirms these deviations, indicating a shift towards warmer hues. In SDR content, the gamma chart reveals slight inconsistencies that make the image appear marginally darker, particularly in shadowed areas, which may obscure finer details in darker scenes.

In 4K HDR content, the EOTF curve exceeds the recommended level, leading to an overly bright display in some parts of the image, which can cause highlights to appear blown out. Overall, the Samsung S90D delivers a solid image straight out of the box, but for the best performance, further calibration is advised, especially with more demanding content.

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."

After calibration, the Samsung S90D in movie mode exceeds expectations. The white balance for HD and 4K HDR content has been refined to near perfection. While minor imperfections remain, they are so subtle that they don’t significantly impact the overall image quality. The colours are now more balanced, resulting in a natural reproduction of details, particularly in scenes requiring an accurate colour palette. It’s important to note that this model, in this size, uses a WOLED panel, which has a smaller wide colour gamut coverage and doesn't deliver the same vibrant colours as the 65-inch version with its QD-OLED panel.

The contrast has also seen notable improvements. Following calibration, the gamma curve now closely aligns with the expected line, achieving a better balance between the bright and dark areas of the image. The EOTF curve, which previously exhibited issues with overexposed scenes, now produces more accurate results, allowing for improved detail retention in the brighter parts of the image, especially in HDR content.

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.

The S90D TV handles tonal transitions exceptionally well. Thanks to advanced technology, the transitions between colours are smooth and natural. The noise reduction function can further enhance the smoothness of tonal shifts, which is particularly useful in certain situations. However, it's important to note that enabling noise reduction can also blur the natural film grain, diminishing the cinematic quality of the image. For this reason, it’s advisable to use this function with caution, as preserving the natural grain can enhance the character and authenticity of the content being watched.

As always, Samsung excels in image scaling from lower resolutions. The S90D effectively processes lower-resolution content, delivering a clear and accurate picture. The model’s outline is crisp, ensuring the image looks natural and detailed. Even the finer details, such as tree branches, are well-rendered without visible jagged edges that could degrade image quality. Thanks to its effective scaling, the S90D ensures that even lower-resolution content looks appealing, satisfying users who enjoy a wide range of content sources, such as regular broadcast or cable TV.

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 Samsung S90D television features a 120 Hz panel, with the option to "overclock" to 144 Hz when connected to a compatible PC, offering exceptional motion smoothness. Samsung has long provided a range of image sharpness settings on a ten-point scale, allowing users to tailor the display to their preferences. In the UFO test, the OLED panel shows no signs of blurring, with pixel response instantaneous and effectively capturing dynamic movements. OLED technology is renowned for its performance in this regard, making it one of the best options on the market. The image remains incredibly sharp and detailed, even during fast-paced action, making the S90D an excellent choice for gamers and sports enthusiasts alike.

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 Samsung S90D is an ideal choice for gamers, featuring four HDMI 2.1 ports that support key gaming technologies such as Auto Low Latency Mode (ALLM), Variable Refresh Rate (VRR), and HDR Gaming Interest Group (HGIG). These features ensure smoother and more responsive gameplay, greatly enhancing performance during intense gaming sessions. The TV also includes a dedicated Game Bar, which makes managing game settings easy. This functionality allows users to quickly adjust parameters like the aspect ratio offering flexibility for different games and gameplay styles. Customising preferences is straightforward, further enhancing the convenience and enjoyment of gaming.

For PC users, the TV impresses by supporting a refresh rate of 144Hz when connected to a computer. Users with Nvidia or AMD graphics cards can also use G-Sync and FreeSync for a smoother gaming experience. However, it’s important to note that the TV does not support Dolby Vision, which may be a drawback for some. That said, Dolby Vision is not as widely adopted in gaming as in film, so this may not be a significant concern for most gamers. Overall, the S90D offers exceptional features for gamers, making it an excellent choice for those seeking outstanding image quality and modern technological solutions.

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.