Samsung QN900F vs TCL A400 PRO

QN900F is really a bright TV – it can generate nearly 2000 nits, which is a value that remains unattainable for most models available on the market. But the mere ability to achieve such brightness is not everything – it also matters whether the TV can use it well. And this is not always perfect. Our tests on movie scenes showed that in scenes such as those from Life of Pi or The Meg, the QN900F can truly shine – literally and figuratively. In such moments, its greatest advantage, which is brightness, makes a huge impression. However, in more challenging scenes, the issues begin – similar to assessing contrast. When smaller, bright elements appear on the screen, the TV often struggles with the decision: whether to highlight them at the expense of black levels, or perhaps maintain deep black but tone down the brightness. The result of this is situations where, for example, in the movie Sicario 2, the brightness dropped to just 200 nits, making details barely visible. The dimming algorithms could definitely be better for a TV of this class.

The TCL A400 Pro is a moderately bright TV. Its peak brightness reaches about 600 nits. That level already allows for a real HDR effect and in many movies it does produce a noticeably more attractive picture than SDR. However, it is not a level that overwhelms by brightness alone. The A400 Pro is not one of those TVs that "attack" the viewer with a powerful flash in every dramatic scene. The biggest limitation is visible with small bright elements on a dark background. Due to rather aggressive control of the dimming zones, 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. That said, this is not done without reason. The A400 Pro does this to keep blacks as deep as possible and to limit haloing around bright objects. It's a deliberate compromise: the TV more often chooses deeper blacks over maximally bright, point-like highlights. On one hand this is understandable, especially with a limited number of dimming zones, but on the other hand you should be aware that the HDR effect will not always be as strong as the peak brightness alone would suggest.

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

Testing the QN900F in Filmmaker mode, one quickly noticed the characteristic features of the image despite the fact that this mode is designed to reflect the director's vision. The white balance was not perfect – the television had noticeable deficiencies in blue color. This made the entire scene take on a warmer tone, as if someone had applied a subtle filter in shades of yellow and orange. In movies where bright shots dominate – for example, scenes in the snow or in strong daylight – this created a slight warming effect, which does not always convey the director's intent. The second noticeable element was brightness management. The QN900F sometimes managed to brighten the image more than necessary. It looked as if the exposure had been slightly "pulled up," causing the scene to lose its naturalness. Shadows were sometimes too shallow, and contrast was slightly weakened. These are not disqualifying errors, but for a television in this price range, it is evident that Filmmaker mode has not been perfected one hundred percent. This is particularly evident when comparing its image to what was visible after screen calibration.

As standard, we carried out color measurements in the best-calibrated mode, Filmmaker Mode, the one that is supposed to be closest to the creators’ intent. The A400 Pro, of course, also offers other picture modes, but in practice they suffer from much larger color errors and alter the image character more strongly. We won’t go into those modes in detail in this part of the test. So how does the factory color reproduction perform? In short: really very well. In fact, looking at our measurement results, it’s excellent. Both the white balance and the luminance response were set surprisingly precisely. The errors were so small that during testing we genuinely rubbed our eyes in disbelief. Such good out-of-the-box settings don’t happen often, even in TVs operating in Filmmaker Mode. All the more reason to praise TCL, because the A400 Pro right out of the box can produce an image very close to how the source material should look. The results were so good that you could easily think someone had already paid extra attention to that unit and tried to calibrate it.

Our nitpicking really comes down to just one thing. In SDR content the image was slightly brighter than the reference for a dark room, because the factory gamma was set closer to 2.3 than to 2.4. It’s not a big error and most viewers probably won’t even notice it.

However, it should be noted that we’re talking about our specific review sample. With factory colors there can always be some variation between units, production batches, or screen sizes. So we don’t assume that every A400 Pro will look identical straight out of the box.

After calibration, we were able to eliminate the errors in white balance and adjust them to a level that can be considered acceptable. It's not perfect, but definitely better than the factory settings. Most color errors are now within the deltaE 2–3 range, so in practice they shouldn't be noticeable during everyday viewing. The biggest improvement is seen in how the television manages brightness in SDR content. Shadows and details are no longer flattened, giving the image depth and naturalness. When it comes to 4K HDR materials, colors themselves are no longer an issue, but some imperfections of the Mini-LED technology can still be observed. The QN900F tends to dim the smallest bright elements too much, causing them to sometimes disappear from view. However, it should be added that this is a much better solution than boosting the entire screen, which would spoil the contrast. It's more of a characteristic of this technology than a typical flaw, but it's worth keeping in mind. The effects of calibration are really very good.

Despite its excellent factory tuning, we couldn't resist checking how the TCL A400 Pro would respond to a professional calibration. Since the starting point was so good, we were even more curious whether we could squeeze even more out of this TV. And here we have to boast: we managed to bring our unit to absurdly low color errors. Results below 1 are something you don't see every day, even on very good TVs. Such results are more often associated with professional reference monitors than with a lifestyle TV for the living room. In terms of white balance and color reproduction, the A400 Pro after calibration simply performed outstandingly. The only thing we can pick at after a deeper analysis concerns the brightness behavior. The TV can manipulate luminance levels depending on the content being displayed, and quite often the image is a bit darker than it should be according to the standard. This most likely stems from the way the Mini-LED backlight and local dimming algorithms work in this model. However, that doesn't spoil the overall impression, because in terms of color precision alone the A400 Pro after calibration reached a level we really didn't expect.

If we would like to eliminate non-fluid tonal transitions that can be annoying, for example while watching YouTube, we can use a feature called noise reduction. It works really effectively – it removes the issues with color blending when we set it to Standard level. However, as with most Samsung televisions, this comes with compromises. Although we did not notice that this feature significantly affects the structure of objects in the image, it unfortunately reacts rather aggressively to film grain. Most people will appreciate this effect – the noise is simply removed – but if someone is looking for an image as close as possible to reference settings, then we definitely recommend turning off this option.

As for scaling, which means handling very low-quality content, the QN900F performs really well. On the test screen with the model, the image looked clear, with only slight aliasing that should not bother most viewers. However, it is worth mentioning one issue – the television has problems with so-called overscan, which can cause older content to be slightly cropped. This can manifest itself, for example, with subtitles disappearing from the bottom of the screen.

Digital video processing is unfortunately one of the weaker points of the TCL A400 Pro. That doesn't mean the TV performs badly, but it's hard to call it anything clearly above standard. The upscaling itself is adequate: edges are smoothed fairly well, the image doesn't look overly sharp or pixelated, and lower-quality content can be watched without major discomfort. At the same time the overall look is slightly soft and it lacks the precision that the best image processors in more expensive TVs can deliver.

Much worse, however, is its handling of tonal transitions caused by heavy compression. TCL equipped the A400 Pro with a "Gradual Smoothing" feature that in theory should reduce visible color banding and artifacts in lower-quality content. In practice its effectiveness is very limited. It does not improve tonal transitions in any noticeable way, and at higher settings it can also smooth out image details, giving the picture an artificial, slightly blurred character. For that reason we think it's best to leave this feature off. The A400 Pro handles basic image scaling decently, but if you often watch heavily compressed content with visible posterization, this model won't be one of the best choices.

There really isn't anything to complain about here – the QN900F looks very good when it comes to motion. Thanks to the 165 Hz panel in 4K, one can confidently say that this TV is suitable for both watching sports and gaming. The motion smoothness feature plays a key role here. It works remarkably well – not only during sports broadcasts, where it can eliminate blurring and image jitter, but also in games, where the animation becomes clearer and smoother. And of course, if someone likes to experiment with movies – they also have that option. At lower settings, there's a slight graininess and filmic character, while at higher settings, it reaches soap opera effect territory. So everyone can adjust the picture to their preferences, and the TV has the power to handle it.

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 used by most consoles today, as well as many sports broadcasts and high-frame-rate content. In this range the TV performs quite well. Motion clarity is really good, especially after properly configuring the motion smoothing. The "Motion Clarity" feature improves smoothness. Its settings include two sliders that let you tailor the motion smoothing to your preferences — separately for lower- and higher-frame-rate material. That way you can achieve either a more cinematic look or a noticeably smoother picture. If you don't want to tweak settings manually, you can use presets such as low, medium, high, cinema, or nature.

[UPDATE] We have updated our 2025 Samsung TV reviews following the release of firmware version 1131, which officially restores the essential HGiG (HDR Gaming Interest Group) support.

It is really nice here. The QN900F offers a full set of features that we would expect from a top-tier gaming television – we have VRR, ALLM, Game Bar, and also cloud gaming applications. However, the biggest highlight is the proprietary motion smoothing, which also works in games and – importantly – does not add noticeable delays. This is something we won't find in its other competitors. Unfortunately, there is also something concerning. This year, Samsung has apparently messed something up with its televisions. During the test of the QN900F before its update, it had the HGIG feature, which allowed for perfect adjustment of HDR settings for the console. However, according to our procedures, we always update the equipment to the latest version – to give the manufacturer a chance to fix any shortcomings. And here… it turned out the opposite. After the update, the HGIG feature disappeared from the menu, making the proper configuration of the console for HDR practically impossible. It was supposed to be complete – 165Hz, four HDMI 2.1 ports, a full gaming package… but unfortunately, it turned out to be a little blunder. Such a shame.

When it comes to features for gamers, the TCL A400 Pro performs excellently. The TV has practically everything you can expect from a gaming TV today: 4K support at high refresh rates, VRR, ALLM, correct implementation of HDR formats in games, including Dolby Vision, and HGiG. Because of that it works well with both next-gen consoles and PCs. Another plus is the inclusion of a Game Bar, a special panel with the most important settings for gamers. From it you can quickly check basic signal information, refresh rate, and active features, and also adjust the look and behavior of some settings to your own preferences. This is 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 complain about 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 functions as eARC. In practice this means that if someone wants to connect two next-gen consoles and a soundbar, they may hit some limitations. In that scenario you'll have to either swap devices or use extra equipment, for example an AV receiver or a soundbar with HDMI inputs. Despite this, it's hard not to rate the A400 Pro very highly as a gaming TV. The gaming feature set here is really powerful.