TCL C9K vs Samsung S90F QD-OLED

As we mentioned with black and contrast – the C9K makes a huge impression in synthetic tests. Our measurements showed that on a screen 10% filled with white, the television is capable of squeezing out... 4000 nits of brightness! It sounds cosmic, but – and here unfortunately the pattern repeats – the numbers say one thing, and practice another. In real film scenes, the situation looks different. In the best case, when the light effects occupy a large part of the image and the local dimming algorithm doesn't have to think too hard about what to do with thousands of zones – the result is really quite good. At that point, the C9K can reach about 1500 nits, which provides a pleasant, intense flash and can indeed make a positive impression.

The problem begins with smaller elements – such as stars in the sky, the moon, or individual reflections. That's when the proverbial cat comes out of the bag: the algorithms are not yet refined, and brightness drops even to 400–500 nits. This is a huge difference compared to the potential of 4000 nits that we saw in laboratory tests. Why does this happen? Most likely, the television tries to protect the black and minimise the halo effect around bright objects. Unfortunately, this comes at the cost of details – some of the intricate details simply disappear, and the scene loses its nature.

The biggest difference between the 65-inch S90F and the other versions is brightness. The QD-OLED panel can reach up to 1700 nits in laboratory tests, which is over 500 nits more than the variant with a WOLED matrix. This translates to a decidedly stronger and more engaging HDR effect. In most scenes, bright parts of the image look fantastic, and we must admit that we were positively surprised, as we expected results more similar to the WOLED version, but we got an effect that makes a great impression even in films. Just like with every OLED, there are moments when the panel needs to limit its brightness a bit. This mainly refers to full-screen, very demanding scenes – for example, in the last test frame from the film "The Meg," the brightness drops to around 800 nits. However, it is hard to consider this a disadvantage, as it is still an excellent result, unprecedented in OLED televisions in this price range. Everything suggests that the 65-inch S90F could be one of the best choices this year for those looking for a strong OLED at a reasonable price. Another advantage of the QD-OLED matrix in HDR content is its colour gamut coverage. Thanks to quantum dots, the television achieves almost a full 100% of the DCI-P3 colour space and nearly 90% of the BT.2020 colour space. These values place it alongside much more expensive models and make it exceptional in its class.

For colour tests, we once again reached for the Filmmaker mode – a new feature in TCL televisions for 2025. And although the direction itself is a step in the right direction, the execution leaves much to be desired. The white balance in SDR content turned out to be too warm – there was an excess of red. Conversely, in HDR, it swung in the opposite direction: the image became excessively blue. The Colour Checker test revealed quite a few colour inaccuracies that were noticeable to the naked eye. An even bigger problem turned out to be what we mentioned above – managing brightness. Regardless of whether we were watching SDR or HDR content, the image had a tendency to blow out the entire scene, giving it an unnatural, almost grotesque character. Therefore, it is hard to call this a 'director’s mode' – because the director surely has never seen such an image.

Samsung S90F, like most modern televisions, offers several picture modes, but in line with our tradition, we tested it in the most important one, which is Filmmaker. This setting makes the image look much more natural than in the default, often overly saturated modes. It is neither excessively vivid nor artificially subdued – just closer to what one should actually see. However, this does not mean it is perfect. The S90F had noticeable shortcomings in white balance, mainly in the blue range, which gave a slightly yellowish filter effect on most scenes. One might argue that it looks more "filmic" because it is warmer, but let’s not kid ourselves – George Lucas didn't shoot Star Wars in sepia 😉 (a comparison with the scene can be found, as always, below). In HDR materials, there was also an issue with brightness management. The EOTF curve clearly showed that the television brightens the picture more than it should, leading to some effects appearing too intense and deviating from the reference. Fortunately, a large part of these shortcomings can be eliminated through professional calibration – we will discuss the effects of this procedure further on in the test.

After calibration, we finally managed to tame the white balance – and it immediately translated into a more natural image. Colours finally started to look as they should, and the overall presentation was incomparably better than with the factory settings. In other words – it’s worth taking a moment to improve this, as the gain is really significant. The gamma responsible for managing brightness was also brought under control in SDR content, and the effect was more than satisfactory. Unfortunately, when we switched on the HDR material, the situation quickly became complicated. No matter how we set the local dimming, the television had a tendency to do what it pleased with the image – either overexposing the whole picture or dimming the darkest parts too much. Just like we saw in the scene from the film Billy Lynn. Colour-wise, the improvement after calibration makes a great impression, but managing brightness in HDR remains the Achilles' heel of the C9K and constitutes a technological limitation.

Calibration quickly revealed that the S90F has a significant margin of capability. The image in SDR immediately gained a natural quality – classic films no longer looked as if someone had applied a yellowish filter to them, and the colours regained their proper character. It is a return to the atmosphere of the original, without the impression that someone tried to "age" it forcefully. In HDR content, the difference was even more pronounced. The EOTF curve was managed almost to a reference level, and any deviations are so subtle that most viewers won't even notice them. In practice, the S90F shows an image very close to perfection after calibration. Compared to the WOLED version, it performs even better – mainly due to the wider colour gamut coverage, which makes the colours appear fuller and more intense.

The digital image processing in TCL C9K is rather mediocre. The tone transition smoothing feature is supposedly present, but activating it hardly makes any difference – colour banding is still visible, and it can inadvertently highlight elements we would prefer to hide, such as textures of objects. Fortunately, it does not remove film grain, but that's scant consolation considering the effects are still poor. Thus, it's hard to recommend using this option.

On the other hand, image scaling performs significantly better. Lower quality materials look quite decent – characters and backgrounds are represented clearly, although of course, with sources like 576p, the limitations of the physics cannot be disguised. Sometimes, there's characteristic aliasing of objects, but that's due to the source itself, not the algorithm. A plus for the fact that there are no overscan issues – the image is neither artificially cropped nor enlarged.

The S90F performs really well here, although there are some comments that recur with most Samsung televisions. The noise reduction feature can effectively smooth out unwanted colour transitions in poorer materials, such as television or YouTube, making them simply look better. However, it should be noted that it operates quite aggressively and can also soften elements we wouldn't want to touch, like facial details. Therefore, if we want to use it, it’s best to set it to 'medium' and be aware of the compromise it entails. The upscaling itself is at a high level – low-quality materials are upscaled towards a 4K-like image. The only caveat is that the S90F can still struggle with so-called overscan, meaning it slightly trims edges with very poor materials like 576p and lower.

Similar to the C8K, the C9K is also a really fast television – both figuratively and literally. On board, we have a 4K panel with a refresh rate of 144 Hz, and at lower resolutions, the panel can even ramp up to 288 Hz. Such speed translates into practice – while watching sports or playing games, the picture looks very smooth and clear. Additionally, in films, we get an extra motion smoothing feature called Motion Clarity, which allows you to adjust the smoothness to your own preferences – from the cinematic "stuttering" of frames to nearly theatrical smoothness.

S90F is an OLED with a refresh rate of 144 Hz, but in practice, it primarily indicates how it performs at 120 Hz, as this frequency is most significant when watching sports. The QD-OLED panel is no different in this regard from WOLED panels – the response of the pixels is nearly instantaneous, so motion is rendered with surgical precision. The result is predictable. The image is virtually devoid of motion blur, making gaming on consoles, matches, or other sports broadcasts incredibly enjoyable on the S90F.

Fans of films and series have not been overlooked either. Like every Samsung television with a refresh rate of 120 Hz and above, the S90F features a proprietary motion smoothing technology called "Image Clarity." Here, we find two sliders – blur reduction and judder reduction – which allow for improved fluidity of materials recorded at 24 frames and tailoring the effect to personal preferences.

For gaming, the TCL C9K is a complete tool. Here we have two (out of four) HDMI 2.1 ports with full bandwidth of 48 Gbps, so all the key technologies work: VRR (Variable Refresh Rate) and ALLM (Auto Low Latency Mode). Additionally, the manufacturer has included a really intuitive Game Bar, which allows you to quickly check the most important parameters and adjust settings without rummaging through the menu. Also worth noting is TCL's policy – the television does not shy away from any HDR formats, even in game mode. Whether it's HGiG or Dolby Vision for the Xbox Series S/X console – everything works as it should, giving the player a wide range of freedom.

The S90F is a television that truly brings a lot of joy when gaming. To start, we have four full-fledged HDMI 2.1 ports, which means you can connect all consoles and PCs without worrying about which device has priority. This is a convenient and practical solution that is by no means a given with other manufacturers. Additionally, there are key features such as automatic game mode (ALLM), which automatically switches the screen to low-latency settings, and VRR frame synchronization that operates in a wide range from 48 to 144 Hz. As a result, the picture remains smooth regardless of whether we're playing fast-paced online shooters or more leisurely narrative titles. The Game Bar also deserves a mention – a panel that allows quick access to several useful additions. For example, you can enable an additional crosshair in the centre of the screen, enlarge the minimap, or, in the case of PC, change the aspect ratio. Lastly, there is also the unique Game Motion Plus mode from Samsung. Its purpose is to smooth out older or poorly optimized titles, and it actually works pretty well. Thanks to this mode, even less polished games can look better and provide a more enjoyable gaming experience than on other televisions that theoretically offer the same technical specifications.