Samsung 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 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.

And what about HDR? Here, the C6KS performs quite well and – as has become a recurring theme of 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 keep in mind 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 blacks. This is quite a reasonable compromise. Most viewers will definitely appreciate deep, "true black" more than additional micro-details, the display of which could cause the screen to appear greyed out. This is the nature of local dimming technology in this price range, and one must be aware of it. It is also worth noting that the TCL C69KS (C6KS) has an additional PFS coating, which is marketed under the slogan of QLED technology. Thanks to this, the colours are saturated and vibrant – our measurements showed that the coverage of a wide colour gamut reaches as much as 92% here.

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.

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

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.

Thanks to the white balance adjustment, the C69KS's tendency to distort colours has been effectively limited, resulting in a very good final effect. After calibration, we will no longer see excessive warming of scenes in SDR or overly cool tones in HDR. However, it is worth noting the brightness characteristics. In SDR content, it is hard to have any objections – the image looks very good, especially in older films, television programmes, or materials from YouTube. It is significantly more challenging to evaluate the television's performance in HDR. Analysis of the EOTF curve suggests correct behaviour, but its practical variant reveals certain limitations. The C69KS can overly brighten the smallest elements of the frame, while at other times, it can dim the entire scene. Thus, calibration brought clear benefits in terms of colour quality, but certain limitations resulting from the local dimming operation and the way it is controlled by the C69KS cannot be overlooked, as we also saw in the C6K test.

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.

The C69KS handles upscaling quite well. The tested 576p material looks surprisingly decent – a considerable amount of detail is retained, and the algorithm adds a slight "rounding" effect to sharp edges, making the image appear more cohesive. The performance in smoothing tonal transitions is less impressive. The television practically cannot improve them, leaving the image in a rather raw state. With older material, this can be quite tiring, as the lack of additional processing highlights any imperfections.

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.

C69KS offers a simplified motion enhancement panel in films, allowing the adjustment of effect intensity with a slider. This makes it easy to match fluidity to personal preferences. The ability to use higher refresh rates is also a plus – although the panel operates natively at 4K at 60 Hz, lowering the resolution to 1440p enables 120 and 144 Hz modes, both on consoles and PC. This sounds like great news, however, in practice, the image at these settings exhibits significant motion blur. The effect is so pronounced that the overall presentation appears merely average and loses its appeal for everyday use.

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.

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