TCL C8L / QM8L vs Samsung S90H (QD-OLED)

In terms of HDR, the TCL C8L turns out to be a hellishly bright television – quite literally. On a synthetic test pattern sized at 5%, our measurement equipment indicated a result exceeding 4500 nits. This is a truly astronomical result, considering that reference monitors used by directors, which we often refer to in our materials, typically operate around 4000 nits. Does this mean that the C8L breaks barriers and climbs to the technological peak of Mini-LED? Not quite. Dry synthetic tests are one thing, while real cinematic images are another. In real, varied scenes, the C8L peaks at around 1600 nits. This is still a very good result, ensuring a very high level of HDR dynamics, but it is also clearly lower than what the manufacturer boasts in the specifications. The problems begin with very small bursts of light – at that point, brightness can drastically drop to around 600 nits. The algorithm tries at all costs to maintain deep blacks and minimise the halo effect, but this comes at the expense of HDR impact. This is perfect evidence that laboratory test patterns rarely align with what we ultimately see on the screen.

However, huge praise is due for colour reproduction, thanks to the new generation of SQD (Super Quantum Dot) quantum dots. The DCI-P3 colour gamut coverage reaches 97%, but the truly jaw-dropping measurements come from the extremely demanding BT.2020 space. The C8L achieves an impressive 90% in this space, placing it alongside today's top screens equipped with RGB backlighting. Importantly, unlike some screens with Micro/Mini RGB backlighting, this effect is stable regardless of the scene displayed. Of course, it’s worth remembering that content mastered for such a wide gamut in films or series is still rare. However, the very fact that the panel has such a "colour reserve" deserves tremendous admiration.

The Samsung S90H is a genuinely bright TV for the mid-range OLED segment. In synthetic tests its peak brightness reached around 1650 nits. That’s an impressive result in this class, roughly 50% higher than what we have seen from previous models in this price bracket. Most importantly, these tests translate directly to real video material. In four out of five film clips we tested, the S90H’s brightness ranged between 1300 and 1500 nits. That headroom allows it to reproduce most HDR films with very high dynamic range and without obvious compromises, especially in material mastered to 1000–1500 nits. In practice light effects, reflections and explosions have the appropriate punch, and the picture does not appear dimmed. Of course, on full-screen very bright scenes the result is naturally lower and drops to around 900 nits. This is a direct result of the OLED panel’s protection systems working to prevent overload. Even in this scenario there is little to complain about. Those 900 nits across the whole screen is still a very high level, ensuring excellent dynamic range in HDR content.

Colour has always been a major strength of QD-OLED TVs, and the S90H is no exception. The DCI-P3 colour space we measured reached a full 100% (actually 99.9%), while coverage of the much wider BT.2020 gamut hit about 89%. That’s an excellent result, enabling very saturated and vivid colours in HDR content. It’s worth emphasising that QD-OLED’s advantage over WOLED panels is not limited to palette coverage alone. In practice it’s mainly visible in the higher brightness of saturated colours, that is in a greater colour volume. As a result, intense reds, greens and blues in HDR look more vibrant and more striking.

We tested the TCL C8L in the best factory mode available in the TV’s menu for image fidelity. That’s of course Filmmaker Mode, which only arrived in this brand’s software relatively recently (a year ago in the "K" series). It allows the average user to achieve quite decent colour reproduction straight out of the box, though it is certainly not perfectly tuned. Looking at the unit’s out-of-the-box white balance — in both SDR and HDR material — the red component was clearly lacking, which made the image noticeably cooler and slightly shift towards blue‑green tints. The issue of brightness management also looks ambiguous, as we mentioned earlier. While the gamma linearity in SDR content is really good and stays steadily at the reference value of 2.4, the situation in HDR is much worse. Tracking the EOTF curve clearly shows the TV has a noticeably boosted brightness across the entire range, so the final image can be excessively bright and inconsistent with the creators’ intent, and this is in a mode that by definition should avoid that. Of course, as with every sample in our lab, we subjected this one to professional calibration, and you can find the results below.

The next stage of the test was to check how the S90H handles colour reproduction without any calibration. As always, we carried out the measurements in Filmmaker Mode, the best factory picture preset. And here Samsung really deserves praise. The factory tuning is at a very high level, and a few years ago this was not one of its strong points. The average colour error (Delta E) remained around 3, which is below the level at which most people can notice any inaccuracies. Only in the brightest shades of grey did the values slightly approach 4, but even then it's hard to regard this as a real problem while watching. For out-of-the-box settings, the result is simply excellent.

As you can see, the results of a professional calibration of the TCL C8L are truly promising, thanks to the comprehensive calibration controls the manufacturer has provided in the menu. Above all, we managed to fully correct the white balance, eliminating the red deficiency, so the image finally stopped drifting into unwanted cool tones. After that adjustment, the errors in the ColorChecker test fell to near-reference values, consistently sitting below a Delta E threshold of 2, i.e. below the visibility threshold for the human eye.

If test patterns look so perfect, you may ask us why the final score in this category is lower. The answer lies in the brightness management described earlier. Although the menu includes sliders that let you precisely straighten the EOTF curve on synthetic signals, when faced with real film material (I recommend enabling the EOTF filter when watching films), it becomes clear that the TV, in most scenarios, still responds to HDR metadata in its own way. As a result, the picture can be slightly over-bright and not faithful to the filmmakers' intent, and it is precisely for this lack of consistency with real films that we had to take a few points off the C8L's score.

All right, but you know we wouldn't be ourselves if we didn't also check how far we could push the S90H after professional calibration. And there was no big surprise. Since the factory settings were already very good, there wasn't much room for improvement. Even so, we managed to refine the picture to near perfection. After calibration the mean colour reproduction errors fell below the threshold of perception, with Delta E values under 2 for both SDR and HDR material. We also improved the brightness response, so the image more faithfully reflects the creators' intent and maintains appropriate tonality across the whole luminance range. After professional calibration the S90H therefore becomes a display very close to reference.

Will the difference be spectacular for everyone? Not necessarily. The factory settings already deliver a very high level, so in everyday viewing some people may not notice a dramatic jump. Much also depends on the individual unit. Our sample was very well tuned straight out of the box, but that doesn't mean every S90H will perform at the same level. Even identical models can differ from each other in terms of factory calibration. That's exactly why professional calibration makes sense: it allows a specific unit to be brought to the highest possible accuracy, rather than relying on a bit of luck when buying.

This year the C8 series and the higher-end models have probably received the biggest and most eagerly awaited upgrade in TCL’s history, and it concerns digital picture processing. The C8L is the entry-level model in the manufacturer's line-up that has been equipped with the latest flagship chip MediaTek Pentonic 800 (listed in the menu as MT9655). It is thanks to its computing power that the feature called "Gradual Smoothing" finally works as it should. The algorithm effectively removes unwanted posterization (ugly tonal transitions / colour banding) from the image, doing so intelligently enough that it does not degrade the sharpness of other details.

The processor also handles upscaling lower-resolution content to 4K very well. Although assessing this element can be largely academic, because the differences between today’s TVs in this class are very subtle. The most important takeaway is that TCL finally has nothing to be ashamed of compared with the competition.

In this respect Samsung has changed practically nothing compared with last year’s model, which is actually quite good news. The feature responsible for smoothing tonal transitions still very effectively limits the posterisation effect. However, you should remember that it works rather aggressively, because besides the artefacts themselves it can also remove film grain and slightly soften fine image detail. As always, this is therefore a matter of compromise and personal preference. If you want the most faithful reproduction of the source material possible, we recommend leaving this function turned off.

There is also little to be said about upscaling in terms of revolution. The S90H uses the same proprietary NQ4 Gen3 image processor as its predecessor, so scaling quality has remained practically unchanged. The TV handles lower-resolution material well, effectively improving its sharpness. However, the overscan problem has still not been solved. With some older material, especially archival recordings, it may happen that a portion of the image at the edges is cropped. It’s a minor flaw, but a shame Samsung has left this issue unchanged for another year running.

The TCL C8L is equipped with a fast panel with a native refresh rate of 144 Hz. This specification will be most appreciated by demanding PC gamers, while most users, who rely on consoles or TV broadcasts, will make use of a stable 120 Hz. It is at 120 Hz that the motion-processing algorithms take care of image processing (in films, series and sports). In the TV menu you'll find a "Motion Clarity" tab that allows you to tailor the motion smoothing to your own preferences. The algorithms cope well with both cinematic productions at 24 or 30 frames per second and with fast-paced sports broadcasts at 50 or 60 frames per second, ensuring appropriate smoothness.

In terms of motion handling the S90H delivers a very high level. A new feature here is a panel with a refresh rate of up to 165 Hz, although in practice that will mainly benefit PC gamers. Films, series and sports broadcasts do not use such high refresh rates, so when watching them the difference compared with the standard 120 Hz will not be noticeable. That said, thanks to the OLED panel's lightning-fast response time motion is very clean and the picture does not suffer from the motion blur typical of many LCDs. Samsung has equipped the television with extensive motion-smoothness settings. You get two sliders: judder reduction and blur reduction, which let you easily tailor the picture's character to your own preferences. You can easily achieve a very smooth image when watching sport, but you can just as well preserve a more cinematic feel at the typical 24 frames per second. It all depends on which effect you prefer.

For gamers – and especially for owners of powerful PCs and several consoles simultaneously – the TCL C8L is a true monster. It is the first model in this manufacturer's lineup to feature as many as four full HDMI 2.1 ports with a maximum bandwidth of 48 Gbps. This is directly attributable to the use of the new Pentonic 800 processor, which we discussed earlier. Additionally, the television seamlessly supports practically every gaming feature. We have an automatic game mode (ALLM) that reduces latency to minimal levels, and full frame synchronization (VRR) operating in an impressive range of up to 288 Hz. There's also talk of standards such as G-Sync or FreeSync from Nvidia and AMD. When it comes to display standards, there are no compromises either: the C8L offers complete support for HDR formats in games, including gaming Dolby Vision and the HGiG profile. We can conveniently manage all of these features from a very readable player bar (Game Bar), which we can personalise to our own preferences. From a purely gaming perspective, there's really nothing to fault the C8L on – well, maybe aside from the previously mentioned slight blurring. But other than that? It's a no-nonsense machine for gamers.

From the outset the Samsung S90H feels like a TV designed with gamers in mind, and it's easy to see why. The manufacturer has equipped it with almost everything you could expect from a modern gaming screen. You get as many as four full-bandwidth HDMI 2.1 ports, support for ALLM and VRR, and very high refresh rates. There's also a clear Game Bar that lets you instantly check key picture parameters or change settings without leaving the game. Another very welcome improvement is the HGiG behaviour. Last year it could cause quite a few problems, but on the S90H it works exactly as it should.

Samsung's ace up its sleeve remains its proprietary Game Motion Plus mode. The feature works similarly to the motion smoothing used for films: it improves animation smoothness in games while keeping input lag at a very reasonable level. For titles running at 30 or 60 fps, with the right settings input lag did not exceed 40 ms in our tests. That's a very good result, especially since with many manufacturers enabling similar features results in delays several times higher. Game Motion Plus does not, of course, replace Dolby Vision Gaming, as it's a completely different type of feature, but overall it's a gaming addition that many players may find more noticeable. Smoother motion in 30/60 fps games often makes a bigger difference than HDR itself (which, incidentally, is often poorly implemented in games).