Samsung S90D / S94D 48" (WRGB OLED) vs TCL C6KS / C69KS / Q6CS

In the tested movie scenes, the Samsung S90D delivers impressive brightness levels, exceeding 800 nits in the first four shots—a very strong result. In the final shot, featuring a full-screen burst of sunlight, brightness drops to approximately 400 nits, which is still acceptable. Notably, larger versions of this model exceed 1,000 nits, offering even more impressive performance. Additionally, the colour space coverage of DCI-P3 at 97% ensures rich and realistic colour reproduction, greatly enhancing image quality. For those considering the size of the S90D, it is worth noting that larger variants with QD-OLED panels deliver even better HDR performance, making them an excellent choice for those seeking optimal visual fidelity.

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.

The Samsung S90D television has been tested in Filmmaker mode, which offers good colour reproduction, although with some imperfections that may be noticeable to more demanding users. This mode may seem too warm, and users who switched from Standard mode may experience a slight shock. It is worth noting that this state of affairs is caused by poor settings, for example, in the white balance, rather than the Filmmaker mode itself. In both SDR and HDR content, the device shows drops in blue colour, causing colours to become warmer than they should be. In practice, this means that some shades, such as sky blue or skin tones, may appear less natural and more tinged with pink or yellow. The Colour Checker test confirms these deviations, showing shifts towards warmer tones. In SDR content, the gamma graph indicates slight fluctuations, causing the image to be minimally darker, especially in shadows. This may affect less distinct details in darker scenes. Meanwhile, in 4K HDR materials, the EOTF curve is above the recommended line, which leads to some parts of the image being displayed too brightly, potentially causing clipping in the brightest areas. Overall, the Samsung S90D presents a solid picture straight out of the box, but for the best results, especially with more demanding content, additional calibration is recommended.

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.

After calibration, the S90D TV delivers an even more impressive performance in movie mode. The white balance for both HD and 4K HDR content is now nearly perfect. While there are still some minor imperfections, they are so subtle that they don't significantly impact the overall image quality. The colours are more balanced, offering a natural depiction of details, especially in scenes that require precise colour accuracy.

It's important to note that the 48-inch model features a WOLED panel, which differs from the larger sizes. This results in a smaller coverage of the wide colour gamut, meaning it doesn't offer the same rich colours as the 65-inch version, which is equipped with a QD-OLED panel.

Contrast has also seen a substantial improvement. The gamma curve after calibration is much closer to the ideal line, achieving a better balance between bright and dark areas of the image. The EOTF curve, which previously showed issues with overly bright scenes, now performs much better, retaining more detail in the bright sections of the image, especially in HDR content.

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 S90D TV excels in smoothing tonal transitions, offering natural and seamless colour shifts. Thanks to its advanced technology, it ensures a smoother visual experience overall. The noise reduction feature can further enhance tonal transitions, making it beneficial in certain situations. However, it’s important to note that enabling noise reduction may also smooth out the film grain, which can detract from the cinematic feel. For this reason, it's advisable to use the feature sparingly, preserving the natural grain that adds depth and authenticity to the content.

Samsung continues to impress with its scaling capabilities, with the S90D effectively processing lower-resolution content. The image is sharp and clear, maintaining proper outlines and presenting details accurately. For example, tree branches are rendered well, with no noticeable jagged edges that would compromise image quality. Thanks to the effective scaling, even lower-resolution materials are displayed attractively, making it a great choice for users who enjoy content from diverse sources, such as regular antenna or cable television.

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.

The S90D TV features a 120 Hz panel, which can be "overclocked" to 144 Hz with the appropriate PC setup, delivering exceptional motion fluidity. Samsung has long offered a range of image clarity settings on a ten-point scale, allowing users to fine-tune the display to their liking. In the UFO test, the OLED panel ensures no ghosting, with pixel response being instantaneous and perfectly capturing dynamic movements. OLED technology, in this regard, is considered one of the best on the market. The image remains incredibly sharp and detailed, even during fast-paced action, making the S90D TV a top choice for gamers and sports fans alike.

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.

The S90D TV is perfectly designed with gamers in mind, offering four HDMI 2.1 ports that support features such as Auto Low Latency Mode (ALLM), Variable Refresh Rate (VRR), and HGIG (HDR Gaming Interest Group). These technologies ensure smoother gameplay and faster screen response, enhancing comfort during extended gaming sessions. The Game Bar feature also provides convenient access to settings like aspect ratio, which can be particularly useful for different game types. For PC users, the television offers an impressive refresh rate of 144Hz, with Nvidia and AMD graphics cards supporting G-Sync and FreeSync, further boosting image smoothness. While the lack of Dolby Vision support may be a limitation, it’s worth noting that this technology is less commonly used in gaming compared to movies. Nevertheless, the S90D still provides excellent features for gamers, making it a top choice for those seeking high-quality visuals and advanced gaming technologies.

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.