Samsung OLED S90F (QD-OLED) vs TCL C6KS / C69KS / Q6CS

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.

And how does the issue of HDR look? Here the C6KS performs quite well and – as is becoming a recurring theme in this review – identically to the C6K model. The maximum brightness generated by this television is around 600 nits. In bright scenes, this translates to a really solid, cinematic effect, and generally, the video materials look good here. However, one must remember the specifics of the dimming algorithm in this model. When very small, bright points (e.g., stars) appear against a dark background, the television can dim them quite significantly. The goal is simple: to eliminate blooming and maintain the best possible black levels. It’s a reasonable compromise. Most viewers will definitely appreciate deep, “true black” more than additional micro-details that could cause grayness on the screen. Such is the nature of local dimming technology in this price range, and one must be aware of it. It’s also worth noting that the TCL C69KS (C6KS) has an additional PFS coating, which is marketed under the tagline of QLED technology. Thanks to this, the colors are saturated and vibrant – our measurements showed that the coverage of a wide color gamut reaches 92% here.

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.

Unlike the more expensive C6K model, the tested C6KS does not have an option labeled Filmmaker Mode in the menu. Is this a reason to cry? Absolutely not. Our tests have shown that in practice, in terms of color reproduction, the absence of this specific label makes virtually no difference. The best available Film/Cinema mode here offers nearly identical picture characteristics to the aforementioned Filmmaker mode in the more expensive model. So we get a very similar image, just under a different name. So if you were wondering whether paying extra for the C6K gives you better colors – the answer is: no, in both cases the base is the same and requires slight adjustments.

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.

Thanks to the white balance adjustment, the tendency of the C69KS to distort colors has been effectively reduced, leading to a very good final effect. After calibration, we won't see excessive warmth in SDR scenes or overly cool tones in HDR. However, it's worth noting the brightness characteristic. In SDR content, there are hardly any objections – the image looks very good, especially in older films, television programs, or materials from YouTube. It is much more difficult to evaluate the performance of the television in HDR. Analysis of the EOTF curve suggests correct behavior, but its practical variant shows certain limitations. The C69KS can overly brighten the smallest elements of the frame, while at other times it can dim the entire scene. Calibration has therefore brought clear benefits in terms of color reproduction, but certain limitations arising from the operation of local dimming and the way it is controlled by the C69KS cannot be avoided, as we also saw in the C6K test.

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.

C69KS handles upscaling quite well. The tested 576p material looks surprisingly decent – a significant amount of detail is preserved, and the algorithm adds a subtle "rounding" effect to sharp edges, making the image appear more cohesive. However, the smoothing of tonal transitions is lacking. The television practically cannot improve them, leaving the image in a somewhat raw state. With older materials, this can be simply exhausting, as the lack of additional processing highlights all imperfections.

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.

C69KS offers a simplified motion improvement panel in movies, allowing you to adjust the intensity of the effect using a slider. This makes it easy to match the smoothness to your own preferences. The possibility of using higher refresh rates is also a plus – even though the panel operates natively at 4K at 60 Hz, lowering the resolution to 1440p allows you to enable 120 and 144 Hz modes, both on consoles and PC. This sounds like great news, but in practice, the image at these settings suffers from significant motion blur. The effect is noticeable enough that the overall experience feels simply mediocre and loses its appeal in everyday use.

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.

If we overlook the smearing and lack of native 4K at 120 Hz, the C69KS impresses with how well it performs during gaming. We get everything you can expect from a gaming television: variable refresh rate (VRR), automatic switching to game mode (ALLM), Dolby Vision Gaming mode, and a reasonably functioning HGiG. The TV can also operate at 120 and even 144 Hz at lower resolutions, allowing for smoother gameplay on console or PC. Additionally, there is a clear Game Bar that lets you quickly glance at key settings during gaming. As a result — despite a few limitations — the C69KS can be a truly successful screen for gamers.