TCL A400 PRO vs Samsung S90H (QD-OLED)

The TCL A400 Pro is a moderately bright TV. Its peak brightness reaches around 600 nits. That level already allows for a real HDR effect and in many films it does deliver a noticeably more appealing picture than in SDR. However, it’s not a level that dazzles by brightness alone. The A400 Pro is not one of those TVs that bombard the viewer with a powerful flash in every dramatic scene. The biggest limitation is visible with small bright elements on a dark background. Because of fairly aggressive zone control, the TV can significantly reduce their brightness, in extreme cases down to around 100 nits. That means small lights, sparks, stars or single highlights can be much less visible than they should be. It should be added, though, that this isn’t done without reason. The A400 Pro does this to keep black levels as deep as possible and to limit the halo effect around bright objects. It’s a deliberate compromise: the TV more often opts for deeper blacks rather than maximising point highlights. On the one hand this is understandable, especially given a limited number of dimming zones, but on the other you should be aware that the HDR effect won’t always be as strong as the peak brightness alone might suggest.

On the plus side, the colours are a strength. The PFS LED filter used here, marketed by the manufacturer as QLED, delivers suitably saturated colours. Our measurements showed about 94% coverage of the DCI-P3 gamut and around 74% of BT.2020, which is a solid result for this class.

The Samsung S90H is a really bright TV for the mid-range among OLEDs. In synthetic measurements its peak brightness reached around 1650 nits. That's an outstanding result in this class, roughly 50% higher than what we’ve seen from previous models at this price point. Most importantly, these tests translate directly to real video material. In four out of the five film scenes we tested the S90H’s brightness hovered around 1300-1500 nits. That kind of headroom lets it reproduce most HDR films with very high impact and without obvious compromises, especially material mastered to 1000–1500 nits. In practice, highlights, reflections and explosions have the right punch and the picture doesn’t feel dimmed. Of course, on full-screen, very bright scenes the result is naturally lower and drops to about 900 nits. That’s a direct effect of the protection systems that keep the OLED panel from being overloaded. Even in that scenario there’s little to complain about. Nine hundred nits across the whole screen is still a very high level, guaranteeing excellent dynamics in HDR content. A huge advantage of QD-OLED TVs has always been the colours, 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 a great result, allowing very saturated and vivid colours in HDR material. It’s worth emphasising that QD-OLED’s edge over WOLED panels isn’t just about gamut coverage. In practice it’s seen mostly in the higher brightness of saturated colours, in other words greater colour volume. That makes intense reds, greens and blues in HDR look juicier and more impressive.

As usual, we carried out colour measurements in the best‑tuned picture mode, Filmmaker Mode, the one intended to be closest to the creators’ intentions. The A400 Pro, of course, also offers other picture modes, but in practice they show much larger colour errors and interfere more with the image character. So we won’t cover them in detail in this part of the review. How does the factory colour reproduction fare? In short: really very well. In fact, looking at our measurements, it’s excellent. Both the white balance and the luminance response were set surprisingly precisely. The errors were so small that during the measurements we genuinely rubbed our eyes in surprise. Such good factory settings don’t happen often, even in televisions running Filmmaker Mode. All the more reason to praise TCL, because the A400 Pro straight out of the box can produce an image very close to how the source material should look. The results were so good you could easily think someone had already given this unit extra attention and tried to calibrate it. Our one bit of nitpicking comes down to a single issue. In SDR material the image was slightly brighter than the reference for a dark room, because the factory gamma was set closer to 2.3 than 2.4. It’s not a large error and most viewers probably won’t even notice it. We should note, however, that we are talking about our specific test unit. There can always be some variation in factory colour between individual units, production batches or screen sizes. We do not assume every A400 Pro will look identical straight out of the box.

The next stage of the test was to check how the S90H handles colour reproduction without any calibration. As always, we took measurements in Filmmaker Mode, the best factory picture setting. And here Samsung really deserves praise. The factory tuning is at a very high level, which wasn’t always the case a few years ago. The white balance was set correctly, as was the brightness response. The average colour reproduction error (Delta E) stayed around 3, which is below the level at which most viewers can notice inaccuracies. Only in the brightest shades of grey did the values slightly approach 4, but it’s still hard to call that a real problem during viewing. For out-of-the-box settings, the result is simply excellent.

Despite the outstanding factory tuning, we couldn't resist checking how the TCL A400 Pro would respond to professional calibration. With such a strong starting point, we were especially curious whether we could squeeze even more from this TV. And here we have to boast: we managed to bring our sample to absurdly low colour errors. Results below 1 are something you don't see every day, even on very good TVs. Such outcomes are more often associated with professional reference monitors than with a lifestyle TV for the living room. In terms of white balance and colour reproduction, the A400 Pro after calibration simply excelled. The only thing we can pick on after closer analysis concerns the brightness response. The TV can vary the luminance level depending on the content being displayed, and quite often the picture is a little darker than it should be according to the reference. This most likely stems from the way the Mini-LED backlight and the local dimming algorithms work in this model. That said, it doesn't ruin the overall impression, because in terms of colour precision the A400 Pro after calibration reached a level that was genuinely hard to expect.

All right, but you know we wouldn't be ourselves if we didn't also check how much we could get out of the S90H with professional calibration. And there was no big surprise. Since the out-of-the-box settings were already very good, there wasn't a huge margin for improvement. Even so, we managed to refine the image almost to perfection. After calibration the average colour reproduction errors fell below the threshold of perception, reaching Delta E values under 2 for both SDR and HDR material. We also improved the luminance response, so the picture more faithfully reflects the creators' intent and maintains correct tonality across the entire brightness range. After professional calibration the S90H therefore becomes a screen 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 huge jump. Much also depends on the specific unit. Our sample was very well tuned straight out of the box, but that doesn't mean every S90H will present the same level. Even identical models can differ in their factory calibration. That's exactly why professional calibration makes sense: it lets you bring a particular unit to the highest possible accuracy, rather than relying on a bit of luck when buying.

Digital image processing is unfortunately one of the weaker points of the TCL A400 Pro. That does not mean the TV performs badly, but it’s hard to call it anything clearly above standard. The upscaling itself is acceptable: edges are fairly well smoothed, the picture does not look overly sharp or “pixelated”, and lower-quality material can be watched without major discomfort. At the same time the overall image has a slightly soft character and you don’t see the kind of precision that the best image processors in more expensive TVs can offer.

Handling of tonal transitions caused by heavy compression is much worse. TCL equipped the A400 Pro with a “Gradual Smoothing” feature that in theory should reduce visible colour banding and artefacts in lower-quality material. In practice, however, its effectiveness is very limited. It does not improve tonal transitions in any noticeable way, and at higher settings it can further smooth image detail, giving it an artificial, slightly blurred character. For that reason we think it’s best to leave this feature off. The A400 Pro copes decently with basic image scaling, but if you often watch heavily compressed material with visible posterisation, this model will not be one of the best choices.

W tej kwestii Samsung praktycznie nic nie zmienił względem ubiegłorocznego modelu, co akurat jest dość dobrą wiadomością. Funkcja odpowiedzialna za wygładzanie przejść tonalnych nadal bardzo skutecznie ogranicza efekt posteryzacji. Trzeba jednak pamiętać, że działa dość agresywnie, bo oprócz samych artefaktów potrafi usunąć również ziarno filmowe i delikatnie zmiękczyć drobne detale obrazu. Jak zwykle jest to więc kwestia kompromisu i własnych preferencji. Jeśli zależy Wam na jak najwierniejszym odwzorowaniu materiału, polecamy pozostawić tę funkcję wyłączoną.

Również w kwestii upscalingu trudno mówić o rewolucji. S90H korzysta z tego samego autorskiego procesora obrazu NQ4 Gen3 co jego poprzednik, dlatego jakość skalowania pozostała praktycznie bez zmian. Telewizor dobrze radzi sobie z materiałami o niższej rozdzielczości, skutecznie poprawiając ich ostrość. Nadal jednak nie rozwiązano problemu z overscanem. W przypadku niektórych starszych materiałów, zwłaszcza archiwalnych nagrań, może zdarzyć się, że fragment obrazu przy krawędziach zostanie ucięty. To drobna wada, ale szkoda, że Samsung kolejny rok z rzędu pozostawił ten problem bez zmian.

The TCL A400 Pro is equipped with a 144 Hz panel, but in practice we're most interested in how it performs at 120 Hz. That's the refresh rate most consoles, as well as many sports broadcasts and high-motion sources, are limited to today. In that range the TV performs quite well. Motion clarity is really good, especially after properly configuring the motion smoothing. The 'Motion Clarity' function improves smoothness. Its settings include two sliders that let you tailor the motion smoothing to your preferences, separately for low-frame-rate and high-frame-rate content. This allows you to achieve either a more cinematic look or a noticeably smoother image. If you don't want to fiddle with manual configuration, you can use built-in presets such as Low, Medium, High, Cinema or Nature.

In terms of motion handling the S90H delivers a very high level of performance. A new feature here is a panel with a refresh rate of up to 165 Hz, although in practice this will mainly benefit PC gamers. Movies, TV series and sports broadcasts don’t use such high refresh rates, so when watching them the difference compared with the standard 120 Hz won’t be noticeable. That said, thanks to the OLED panel’s instantaneous response time, motion is very clean and the image doesn’t suffer from the smearing common to many LCDs. Samsung has equipped the TV with extensive motion settings. You get two sliders: judder reduction and blur reduction, which let you easily tailor the image’s character to your preferences. You can easily achieve very smooth motion for sport, but you can just as easily preserve a more cinematic feel at the typical 24 fps. It all comes down to which effect you prefer.

In terms of gaming features the TCL A400 Pro performs brilliantly. The TV has practically everything you’d expect from a gaming TV today: support for 4K at high refresh rates, VRR, ALLM, correct implementation of HDR formats in games, including Dolby Vision, and HGiG. That means it works well with both next‑gen consoles and PCs. Another plus is the inclusion of a Game Bar, a dedicated panel with the most important settings for gamers. From it you can quickly check basic information about the signal, refresh rate or active features, and customise the appearance and behaviour of some settings to your preferences. It’s a solution that may not change picture quality by itself, but it greatly improves the convenience of using the TV while gaming. The only thing to criticise is the number of full HDMI 2.1 ports. The A400 Pro has only two such ports out of four, and one of them also serves as eARC. In practice this means that if you want to connect two next‑gen consoles and a soundbar you may run into some limitations. In that scenario you’ll need to either swap devices or use extra equipment, such as an AV receiver or a soundbar with HDMI inputs. Even so, it’s hard not to rate the A400 Pro very highly as a gaming TV. The gaming feature set here is genuinely powerful.

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

Samsung's real ace, however, is its proprietary Game Motion Plus mode. The feature works much like the motion smoothing used in 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 in our testing never exceeded 40 ms. That's an excellent result, especially since on many manufacturers' TVs enabling similar features results in delays several times higher. Game Motion Plus doesn't replace Dolby Vision Gaming, of course, since it's a completely different type of feature, but overall for gaming it's an addition that many players may find more noticeable. Smoother motion in 30/60 fps games often makes more of a difference than HDR itself, which, incidentally, is often poorly implemented in games.