TCL C9K vs Samsung OLED S90F (QD-OLED)

As we mentioned with black and contrast – the C9K can make 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 astronomical, but – and here, unfortunately, the pattern repeats – the numbers say one thing, and practice says another. In real movie scenes, the situation looks different. At best, when the light effects occupy a large part of the image and the local dimming algorithm does not have to think too hard about what to do with thousands of zones – the effect is really good. At that point, the C9K can reach around 1500 nits, which provides a pleasant, intense flash and can indeed make a positive impression.

The problem starts with smaller elements – such as stars in the sky, the moon, or single reflections. That’s when the proverbial cat comes out of the bag: the algorithms are not yet refined, and brightness drops to even 400–500 nits. That’s a huge difference compared to the potential 4000 nits we saw in laboratory tests. Why does this happen? Most likely, the television is trying to protect the blacks in this way and minimize the halo effect around bright objects. Unfortunately, this comes at the cost of details – some details simply vanish, 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 achieve up to 1700 nits in laboratory tests, which is over 500 nits more than the variant with the WOLED panel. This translates to a significantly stronger and more engaging HDR effect. In most scenes, bright parts of the image look fantastic, and we have to admit we were pleasantly surprised because we expected results closer to the WOLED version, but we got an effect that makes a big impression even in movies. As with any OLED, there are moments when the panel has to limit brightness somewhat. This mainly concerns full-screen, very demanding scenes – for example, in the last test frame from the movie "The Meg," brightness drops to around 800 nits. However, it's hard to consider this a flaw since it’s still an excellent result, unprecedented in OLED TVs in this price range. All signs indicate 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 panel in HDR content is its color gamut coverage. Thanks to quantum dots, the television achieves almost full 100% of the DCI-P3 color gamut and nearly 90% of the BT.2020 gamut. These values place it alongside much more expensive models and make it exceptional in its class.

For color tests, as always, we reached for the Filmmaker mode – a new feature in TCL TVs for 2025. And while 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. On the other hand, in HDR, it went in the opposite direction: the image became excessively blue. The Colour Checker test revealed quite a few color errors that were noticeable to the naked eye. An even bigger problem turned out to be what we mentioned above – brightness management. Regardless of whether we were watching SDR or HDR content, the image tended to blow out the entire scene, giving it an unnatural, even grotesque character. It's hard to call this a "director-created" mode – because the director has certainly never seen such an image.

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

After calibration, we finally managed to tame the white balance – and it immediately translated into a more natural image. Colors finally started to look the way they should, and the overall presentation was incomparably better than in the factory settings. In other words – it’s worth taking a moment to improve this, as the gain is truly significant. The gamma responsible for managing brightness was also brought into order in SDR content, and the effect was more than satisfying. Unfortunately, when we turned on HDR materials, the situation quickly became complicated. No matter how we set the local dimming, the television had a tendency to do what it liked with the image – either it overexposed everything or dimmed the darkest parts too much. Exactly as we saw in the scene from the movie Billy Lynn. So, the color improvement after calibration makes a great impression, but brightness management in HDR remains the Achilles' heel of C9K and presents a certain technological limitation.

Calibration quickly showed that the S90F has a substantial reserve of capabilities. The image in SDR immediately gained a natural quality – classic films stopped looking as if someone had applied a yellowish filter to them, and the colors regained their true character. It’s a return to the atmosphere of the original, without the impression that someone tried to "age" it artificially. 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 after calibration displays an image very close to perfection. Compared to the WOLED version, it performs even better – mainly due to the wider color gamut coverage, which makes the colors look fuller and more vibrant.

Digital image processing in TCL C9K is quite mediocre. The tonal smoothing feature seems to be present, but turning it on practically changes nothing – color bands are still visible, and it can unintentionally highlight elements we would prefer to hide, such as textures of objects. Fortunately, it doesn’t remove film grain, but that’s small comfort since the effects are still poor. Therefore, it's hard to recommend using this option.

On the other hand, image scaling performs much better. Lower quality materials look quite decent – characters and backgrounds are presented clearly, although, of course, with sources at 576p, physics cannot be fooled. Sometimes, characteristic aliasing on objects appears, but that’s the fault of the source itself, not the algorithm. A plus for not having issues with overscan – the image is not artificially cropped or enlarged.

The S90F performs really well here, although there are some comments that are repeated in the case of most Samsung TVs. The noise reduction feature can effectively smooth out unwanted color transitions in lower-quality 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 that we wouldn't want to touch, like facial details. Therefore, if we want to use it, it’s best to use it in the "medium" setting and be aware of the compromise it brings. The upscaling itself is at a high level – low-quality materials are enhanced towards a 4K-like image. The only caveat is that the S90F can still have problems with so-called overscan, which is slight trimming of the edges in very poor materials like 576p and lower.

Like the C8K, the C9K is also a really fast television – both figuratively and literally. It features a 4K panel with a refresh rate of 144 Hz, and at lower resolutions, the display can even ramp up to 288 Hz. This speed translates into practice – when watching sports or playing games, the image looks very smooth and clear. Additionally, in films, we get an extra motion smoother called Motion Clarity, which allows us to adjust the fluidity to our own preferences – from the cinematic "judder" frame to almost theatrical smoothness.

S90F is an OLED with a refresh rate of 144 Hz, but in practice, what matters most is how it performs at 120 Hz, as this frequency is the most significant when watching sports. The QD-OLED panel is no different in this regard from WOLED panels—the pixel response is almost instantaneous, allowing motion to be rendered with surgical precision. The effect is easy to predict. The image is practically free of ghosting, making gaming on consoles, matches, or other sports broadcasts a great pleasure on the S90F.

Fans of movies and series are not forgotten either. Like every Samsung TV with a refresh rate of 120 Hz and above, the S90F is equipped with a proprietary motion smoother called "Image Clarity." Here, we find two sliders—motion blur reduction and judder reduction—that allow you to improve the fluidity of materials recorded at 24 frames and adjust the effect to your 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 key technologies work: VRR (variable refresh rate) and ALLM (automatic low latency mode). Additionally, the manufacturer added a really intuitive Game Bar, which allows you to quickly preview the most important parameters and adjust settings without digging through the menu. Also, TCL's policy is a plus – the TV is not afraid of 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 wide freedom.

S90F is a television that truly brings a lot of joy when gaming. Right off the bat, we get four full-fledged HDMI 2.1 ports, which means you can connect all consoles and PCs without having to figure out which device takes priority. This is a convenient and practical solution that is not a given with other manufacturers. Additionally, there are key features such as the automatic game mode (ALLM), which switches the screen to low-latency settings, and VRR frame synchronization working over a wide range from 48 to 144 Hz. This ensures that the picture remains smooth regardless of whether we are playing fast-paced online shooters or calmer story-driven titles. Another noteworthy feature is the Game Bar – a panel that allows quick access to several useful additions. For example, you can turn on an additional crosshair in the center of the screen, enlarge the minimap, or, in the case of a PC, change the aspect ratio. Finally, there is also the unique Game Motion Plus mode exclusive to Samsung. Its purpose is to smooth out older or less optimized titles, and it actually works quite well. Thanks to this mode, even less polished games can look better and provide more enjoyment than on other televisions that theoretically offer the same technical specifications.