Samsung QN990F vs TCL C6KS / C69KS / Q6CS

The Samsung QN990F belongs to the bright televisions category, and this is immediately evident in tests. In measurements, it achieved around 1300 nits, which in practice allows for enjoying films as their creators intended. Bright scenes have the right intensity, lights shine, and the experience is truly cinematic. In standard test patterns, sequences number 1, 3, and 5 performed best – there, brightness maintained around 800-1000 nits, and the image looked very natural. In more challenging segments, it could drop to around 600 nits, but even so, the level remained sufficient for details to be clearly visible. However, it should be added that in highly contrasting shots, the halo effect returns – the same one we mentioned regarding black levels. Bright elements can leave a halo on dark backgrounds, and this stands out immediately. Since we are dealing with a QLED, the colour palette is expanded, and the colours appear striking. The problem is that with such a flagship model, we expected better numbers. 91% DCI-P3 coverage and about 67% BT.2020 are results that can be considered solid, but not outstanding. This gives a vibrant and appealing image, yet the competition in this and lower price tiers can showcase even more.

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.

We tested the QN990F in Filmmaker mode, which is the best available right out of the box. Right from the start, we noticed several significant errors. The biggest issue concerned white balance. Due to too little blue, and also improper ratios between red and blue, the image – especially in scenes with a lot of white – appeared too yellow, and at times even orange. On the Color Checker palette, these errors didn't look dramatic as they hovered around a value of 4, but in everyday viewing, especially with strong whites, they were most noticeable. We also observed issues with brightness management – the television struggled to maintain detail in the smallest parts of the image, mainly due to the way it controls the backlighting zones. Fortunately, Samsung offers a lot of room for adjustment when it comes to calibration settings. We know that with the right calibration, much more can be extracted from this screen.

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.

After completing the calibration, we managed to bring the white balance back to order and eliminate the previous shortcomings in the shades of blue. As a result, the image no longer looked as if it had a slightly yellowish filter applied – the whites are purer, and the overall presentation is much more natural. We also managed, to some extent, to tame the brightness characteristics in HDR content. The television now handles detail retention in blacks significantly better and does not lose them to the same degree as before. However, when we look at the EOTF curve and the way the QN990F reproduces brightness in films, it is evident that it still tends to accentuate details in dark areas more strongly. This is a characteristic feature of Mini-LED technology and, more specifically, the way it is managed by the QN990F, which is practically impossible to completely eliminate. Despite this, after calibration, the image appears much more natural, mainly due to the correct exposure of white light. The final effect is definitely more pleasant to perceive and closer to what we expect from a flagship television.

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 biggest praise for the QN990F should be given for its upscaling. The processor responsible for "lifting" classic television to 8K resolution does quite well. While watching material in 576p signal, we had no illusions that we would suddenly see a miracle in advertising style, where the image magically transforms into crystal-clear 8K. Nevertheless, the end result was surprisingly good; the image looked clean and sharp. It’s just a shame that the television, like most Samsung models, has an overscan issue, slightly cropping the edges of the screen from the left side.

When it comes to image processing, Samsung offers a feature called "noise reduction," which in theory should improve tonal transitions in older materials, where they are usually more visible. Unfortunately, we felt quite disappointed here. The feature performs poorly – it does not handle unwanted stripes and can introduce its own artifacts. On the plus side, the television does not remove film grain when using this feature, but in practice, that is a poor consolation since the noise reduction itself proves to be virtually useless.

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.

QN990F can comfortably be called one of the fastest televisions in the world. In 4K mode, it is capable of displaying images at a frequency of up to 240 Hz, which until now has been more associated with gaming monitors than with televisions in the living room. However, in everyday viewing, what matters more is how it handles the 8K signal at 120 Hz – and here it performs very well too. Motion remains smooth, and the television manages without a hitch even with the most demanding content. Additionally, there is the motion smoother, i.e. "Picture Clarity". Thanks to it, one can adjust the image to their own preferences – leaving a slightly cinematic judder or switching to maximum fluidity, which works exceptionally well, for example, in sports broadcasts.

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.

It must be said outright – the QN990F is one of those televisions that practically scream that they were designed with gamers in mind. Samsung has been developing its gaming solutions for years, but here we have a truly comprehensive set. Sure, it lacks Dolby Vision support in games, which is a downside that will always come up in discussions. However, aside from that, the list of features is impressively extensive. To begin with, we have the Game Bar – a handy menu that allows you to quickly check and change gaming-related settings. You can see, for example, the enabled VRR, frame rate, or aspect ratio settings. It’s like a little “dashboard,” making it unnecessary to dig deep into the menu to make adjustments. Speaking of VRR: yes, variable refresh rate is present here and works flawlessly. And there's ALLM, which automatically switches the television to game mode as soon as the console is powered on. These may seem like small details, but together they make using the QN990F simply comfortable and hassle-free.

However, the most impressive aspect is the number of ports. Four wireless HDMI 2.1 ports are already great news, as there is no need to choose whether to connect the console, the amplifier, or perhaps even a PC. There’s ample space for everything here. And if we add another micro HDMI (which we recommend connecting directly to the console), hidden in the casing, we practically have five inputs in full 2.1 standard. Let’s also add support for high refresh rates – 120 Hz at 8K and even 240 Hz at 4K – and we get a television that not only keeps up with the new consoles but also feels ready for consoles that are not yet available.

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.