Samsung QD-OLED S90D / S94D vs TCL C8K

In the HDR effect quality category, Samsung S90D achieves remarkable results. On the luminance chart up to 10% window, the TV exceeds the magical threshold of 1000 nits, which is an impressive outcome. However, in the film scenes we tested, these values were slightly lower. Additionally, in the case of a scene with fullscreen sunlight glare, brightness drops to around 500 nits, but it still remains at a very good level. It is worth mentioning that this model stands out with very high colour gamut coverage, thanks to the QD-OLED panel used, which gives it an advantage over TVs with WOLED panels that cannot achieve such a wide spectrum of colours.

TCL C8K is a really bright television. In synthetic conditions – that is, during tests with brightness charts – it was able to achieve even 3500 nits peak brightness in movie mode. That's an impressive result and brings the C8K close to the market leaders, at least when it comes to panel brightness. More importantly – these aren't just numbers on paper. In films with a lot of bright scenes, such as Life of Pi or The Meg, the brightness clearly exceeds 1000 nits, providing a true sense of HDR effect. The picture in those moments looks very dynamic, colors are saturated thanks to excellent coverage of the color palette, and the lights are – spot on and intense. Exactly how it should be.

However, this doesn’t mean that everything is perfect. Just like in contrast tests, here too, in more demanding scenes, compromises appear. In sequences with very fine light elements – such as stars in the night sky or reflections in dark rooms – the local dimming algorithm can… get confused. Instead of bringing those details up, the television sometimes decides to dim them significantly – down to around 300 nits – to maintain deep blacks. On one hand, this is quite a sensible approach (better deep black than a grey/navy blue screen), but on the other – there may be moments when certain elements of the picture become difficult to see or even disappear into darkness.

TEST UPDATE (20/08/2025): The brightness control algorithm in this model is quite problematic – attempting to calibrate the picture so that it doesn’t drastically overexpose the brightest scenes results in unnatural shifts: improvement in one part of the image results in deterioration in another. The television may achieve slightly higher readings in brightness measurements, but in practice, this comes with a heavily overexposed image that looks very unnatural!

For the record, we provide brightness values without this adjustment:

1. 1463 nits

2. 640 nits

3. 1368 nits

4. 468 nits

5. 1025 nits

Samsung 65 S90D with a QD-OLED panel has been tested in Filmmaker mode, which the manufacturer has been using for years to provide the best possible picture settings. In this mode, the TV offers a fairly decent image but with some shortcomings worth noting. In terms of white balance in HD content, viewers may notice a dominance of the red color. This effect can lead to the impression that certain skin tones appear unnatural and the overall scene will be too warm, which in turn can affect immersion in the watched material. In scenes where subtle differences in color are crucial, these distortions can be particularly noticeable. Similar sensations may also occur in 4K HDR content. Changes in white balance in this case can be analogous, with a noticeably smaller deviation in red color. This can also cause certain details and colors to not be fully represented, making the image lose its naturalness.

When it comes to contrast, the gamma presents quite well, however, some errors are still noticeable. Gamma values are below the reference level of 2.4, which can result in bright areas of the image being washed out and dark areas lacking detail. This limitation can cause some scenes to lack depth and detail, which in turn affects the overall presentation quality. On the other hand, the EOTF curve related to contrast in 4K HDR content performs really well, showing that the TV can effectively convey differences in brightness. Nevertheless, it is worth noting that these values are slightly below the ideal level on the graph, indicating the need for further optimization in this regard.

Samsung S90D in Filmmaker mode offers solid color reproduction, but requires some adjustments to fully realise the potential of the TV, especially in the context of different types of content.

In the C8K, a new picture mode has appeared: Filmmaker Mode. This is something we've known for years from televisions of other brands – a mode designed to deliver the director's vision as faithfully as possible, without unnecessary image enhancements. Unfortunately, at TCL, it seems to still be in the "to be refined" stage. Right from the first glance, the screen appears too warm – the image veers into reds, which may not appeal to everyone. The white balance was markedly skewed – the screen looked distinctly warm, and the red colour dominated almost every scene. There was a lack of blue, which led to an unpleasant yellowing and distortion of the image. But that’s not all. Regardless of whether we were watching regular TV, YouTube, or HDR films – the television had a clear tendency to excessively brighten the image. In tests of gamma curves and EOTF, the lines strayed instead of adhering to the standard, resulting in an overly bright and less contrasting image. Additionally, in colour reproduction tests, significant deviations were noticeable – on the colour wheel, some points were actually "drifting away." It must be said plainly: Filmmaker Mode in the C8K, in its current form, is not very cinematic.

After calibrating the TV, the Samsung S90D in film mode gains quality more than one might expect. The white balance for HD and 4K HDR content has been adjusted to near perfection. Although minor shortcomings can be noticed, they are subtle enough that they don’t significantly impact the overall picture quality. The colours have become more harmonised, aiding in the natural reproduction of details, particularly in scenes that require precise colour representation. It is worth noting that this model, in this size, uses a QD-OLED panel which offers broader colour gamut coverage compared to other sizes of this model that are equipped with a WOLED panel.

The contrast has also significantly improved. After calibration, the gamma graph is much closer to the expected line, providing a better balance between light and dark tones in the picture. The EOTF curve, which before calibration indicated issues with overexposed scenes, now shows significantly better results. This effect allows for the retention of more details in the bright areas of the image, especially in HDR materials.

After professional calibration, the TCL C8K has made a huge leap forward. In SDR content, the white balance has been almost perfectly set – the screen has finally stopped being too warm and has taken on a neutral character. The gamma curve, which is responsible for how brightness is represented, now looks very good – the image is more coherent and realistic. In HDR content, we also improved the white balance – within the limits of what the television itself allows. Unfortunately, the C8K still interprets brightness management a bit "in its own way." When we look at the EOTF chart in films, it’s clear that the television brightens entire scenes more than it should. Before calibration, this effect was quite bothersome – now the situation is much better, although it still falls a bit short of perfection. This, however, is a limitation of the device itself, which – despite our efforts – does not allow us to fully tame its nature.

The television handles tonal transitions excellently, allowing colours to flow smoothly into each other, creating a natural image. The built-in noise reduction feature can further enhance these transitions, which can be useful in certain situations. However, it is worth remembering that activating this option may lead to excessive smoothing of the desired film grain structure, which in turn can affect the authenticity and atmosphere of the image. Therefore, caution is recommended when using this feature to avoid losing the character and depth of the content.

The Samsung S90D model effectively processes materials in lower resolutions. This can be seen in the displayed image. The model's silhouette is clear and naturally reproduced, with details well preserved. Additionally, the branches of the trees are well-defined, showing no visible jagged edges that could degrade the quality of the image. Thanks to effective upscaling, even lower resolution materials look attractive on the screen, which will surely please users enjoying a variety of content sources, such as standard cable or antenna television.

How does the TCL C8K handle lower quality materials? One could say: fairly well, though without much enthusiasm. The television offers a tonal transition enhancement feature designed to smooth out unwanted gradients. In practice, there's a slight improvement visible, but it's not at a level that eliminates all imperfections. The feature subtly softens harsh transitions, but it doesn't work miracles. Film grain isn't completely suppressed, and subtle banding on grey backgrounds can still be noticeable. But maybe that's for the best? – at least the image doesn't lose its texture or depth, as is often the case with televisions that overdo digital processing. When it comes to upscaling, which is enhancing picture quality from lower resolutions, the C8K performs quite well. The image is sharp, and details – though sometimes a bit softened – remain discernible. However, it's not on par with the best picture processors from the competition. On the plus side, there's no issues with overscan, which is the artificial cropping of the image that can still surprise in some models from other brands.

Samsung S90D TV, equipped with a refresh rate panel of 120 Hz, and in the appropriate PC configuration even 144 Hz, ensures excellent motion fluidity. Samsung focuses on a variety of image clarity settings on a ten-point scale, giving users the freedom to adjust the display to their own preferences. In UFO tests, the OLED panel shows its strengths, eliminating any blurring. The lightning-fast pixel response makes dynamic movements faithfully reproduced.

Similar results can be observed in other sizes of this model with a WOLED panel, which also offer excellent image fluidity. Organic technology, in this case, is considered one of the best on the market. The picture of Samsung S90D, regardless of the type of panel, is incredibly sharp and detailed, making this TV perfect for dynamic scenes, both during gaming and sports broadcasts. Additionally, its capabilities in terms of refresh rate and clarity ensure that every movement is smooth and natural, which will certainly satisfy even the most demanding users.

If you're planning a weekend with the Champions League or a marathon of F1 racing – the TCL C8K won't let you down. The television is equipped with a 144 Hz panel, so it should inherently handle fast motion well. And indeed – it performs very well. The fluidity of motion is at a very good level here, and the "Motion Clarity" feature with two sliders (blur reduction and flicker reduction) allows you to easily adjust the effect to your own preferences. Want to slightly smooth things out – no worries. Prefer a cinematic look – no problem.

Television S90D is an excellent solution for gamers, offering a range of advanced features that elevate the gaming experience to a new level. Equipped with the HDMI 2.1 standard, the model supports modern technologies such as VRR (Variable Refresh Rate) and ALLM (Auto Low Latency Mode). Thanks to these solutions, the image is incredibly smooth, and the response to commands is instantaneous, which is crucial in dynamic titles. Additionally, the S90D supports HLG (Hybrid Log-Gamma) and G-Sync and FreeSync image synchronisation. This allows for a perfect connection with the Xbox, PlayStation, or PC, eliminating issues with tearing and stuttering. The built-in operating system offers the Xbox Game Pass app, providing access to a massive library of games directly from the television. This solution makes gaming even more convenient and accessible. The Game Bar feature provides quick access to important information, such as current settings, performance statistics, and the ability to adjust image options. This allows for on-the-fly modification of display parameters, which is incredibly useful during intense gameplay. Despite lacking support for Dolby Vision, Samsung S90D still delivers excellent HDR image quality, allowing for full utilisation of the potential of games and films. As a result, S90D represents a unique combination of modern technologies, excellent image quality, and intuitive features, perfect for any gaming enthusiast.

TCL C8K offers practically everything we could expect from a screen for gamers. It has variable refresh rate (VRR), automatic game mode (ALLM), Dolby Vision in games, and a well-functioning implementation of HGiG, which helps preserve the creators' intent in HDR titles. The TV also supports 120 Hz in lower resolutions without any problems, and it can even display a staggering 288 Hz in Full HD – a figure that will surely appeal to fans of dynamic shooters and sports games on PC.

On board, we also find the GameBar – a graphical interface that somewhat resembles an elongated Nintendo Switch console. Thanks to this, we gain quick access to information about the current game mode, frame count, HDR format, and other little details that really make life easier for the gamer. We obviously couldn’t resist and ran a couple of races in Forza Horizon on the C8K – and we must admit, it looked and worked really well.

However, there is a slight drawback – in such a fast and clearly gaming-oriented device, it's a bit unfortunate that the manufacturer opted for the implementation of only two HDMI 2.1 ports. For some users, who use several next-gen consoles and, for example, a soundbar with eARC, this could be a limitation that’s hard to overcome.