TCL A400 PRO vs Samsung OLED S95H (S99H) (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 produce a noticeably more attractive picture than in SDR. However, it is not a level that overwhelms with sheer brightness. The A400 Pro therefore isn’t one of those TVs that ‘attack’ the viewer with a powerful flash in every eye-catching scene. The biggest limitation is seen with small bright elements on a dark background. Because of fairly aggressive local dimming control, the TV can significantly reduce their brightness, in extreme cases even to around 100 nits. This means that small lights, sparks, stars or individual highlights can be much less visible than they should be. It’s worth adding, however, that this isn’t without reason. The A400 Pro does this to maintain as deep a black level as possible and to limit the halo effect around bright objects. So it’s an intentional compromise: the TV more often opts for deeper blacks rather than maximally bright, point-like highlights. On one hand this can be understood, especially given the 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, allows for suitably saturated colours. Coverage of the DCI-P3 gamut measured around 94%, and BT.2020 around 74%, which is a solid result for this class.

When it comes to brightness alone, the S99H is an astronomically bright TV. Its peak brightness in film scenes can exceed 2800 nits. Whatever the scene, you can count on powerful HDR effects that are almost blinding, exactly what you expect from a top-tier screen. It is the nature of OLED panels that they cannot sustain the same extreme brightness in very bright, full‑screen frames as they can with small highlights, but the results are still excellent. In a bright scene from the film The Meg, the sun still exceeded 2200 nits. That means the S99H managed to sustain higher brightness than most Mini LED displays on the market. In terms of brightness, the S99H is currently the best OLED TV we have tested.

Colour gamut coverage

The S99H also handles colour extremely well, which is a direct result of the QD-OLED panel used here. Whether the test scenarios were synthetic test patterns or measurements taken with film material playing in the background, the results remained at a very high level. The S99H easily covers almost 100% of the DCI-P3 gamut, and for the more demanding BT.2020 colour space it reaches nearly 90%. That is absolute top-tier performance. These results match what we have seen in the new SQD-Mini-LED screens, and in real film scenes even outperform RGB Mini LED displays.

As standard, we performed colour measurements in the best‑tuned Filmmaker Mode, the mode that is designed to be closest to the creators' intentions. The A400 Pro of course also offers other picture modes, but in practice these come with considerably larger colour errors and interfere more with the character of the image. Therefore we will not deal with them in detail in this part of the test. So how does the out‑of‑the‑box colour reproduction fare? In short: really very good. Actually, looking at our measurement results, downright excellent. Both the white balance and the luminance response were set surprisingly precisely. The errors were so small that during measurements we genuinely rubbed our eyes in amazement. Such good factory settings do not happen often, even in TVs operating in Filmmaker Mode. All the more credit is due to TCL, because the A400 Pro right out of the box can deliver an image very close to how the source material should look. The results were so good that one could easily think someone had already given this unit extra attention and tried to calibrate it.

Our nitpicking really comes down to just one thing. In SDR content the image was slightly brighter than the dark‑room reference intends, because the factory gamma was set closer to 2.3 than to 2.4. This is not a large error and most viewers will probably not even notice it.

It should, however, be noted that we are talking about our specific test sample. With factory colours there can always be some variation between units, production batches or screen sizes. We do not assume, therefore, that every A400 Pro will look identical straight out of the box.

Samsung offers a whole host of picture modes and features, but as usual we recommend choosing Filmmaker Mode, especially if you want the most faithful rendering of the filmmakers' intent. Out of the box the TV is tuned very well, although it has minor shortcomings. These are mainly a slight drift in the white balance in SDR content and a slightly low gamma. As a result, in darker viewing conditions the picture can be a little too bright compared with the reference gamma of 2.4, which is the standard for watching films with the lights off. These are, of course, minor points, because overall colour reproduction remains at a very good level and the errors in the ColorChecker measurements are not large. However, we know that with a screen of the S99H's class you can, and arguably should, expect even more, which is why we carried out a professional calibration.

Despite its superb factory calibration, we couldn't resist checking how the TCL A400 Pro would respond to professional calibration. Since the starting point was so good, we were all the more curious whether there was anything more to be had from the TV. And here we must boast: we managed to reduce our unit's colour errors to absurdly low levels. Measurements below a value of 1 are not something you see every day, even in very good TVs. Such results are more commonly 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 therefore simply performed exceptionally well after calibration. The only gripe we have after closer analysis relates to the luminance behaviour. The TV adjusts luminance depending on the content being displayed and quite often the picture is slightly darker than the reference calls for. This is most likely due to the way the Mini-LED backlight and local dimming algorithms operate in this model. However, this does not spoil the overall impression, because in terms of colour accuracy alone the calibrated A400 Pro showed a level that was really hard to expect.

After professional calibration, FILMMAKER mode looks practically perfect. Because Samsung offers a rich set of advanced calibration features, we were able to fine-tune the colours to an almost perfect level. Above all, we managed to even out the white balance and the gamma curve, which resulted in noticeably improved contrast and proper image modelling. In this tuned picture profile there really isn't a single thing to criticise or call a flaw. After calibration, the S99H can deliver an essentially reference-quality image.

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 is hard to call it anything clearly above average. The upscaling itself is adequate: edges are smoothed fairly well, the picture does not look overly sharp or "pixelated", and lower-quality content can be watched without much discomfort. At the same time, the overall image is slightly soft and lacks the precision offered by the best image processors in more expensive TVs.

Much worse, however, is how it handles tonal transitions caused by strong signal compression. TCL has equipped the A400 Pro with a "Gradual Smoothing" feature that, in theory, should limit visible colour banding and artifacts in lower-quality material. In practice, though, 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 is best to leave this feature off. The A400 Pro copes decently with basic image scaling, but if you often watch heavily compressed content with noticeable posterisation, this model will not be among the best choices.

The proprietary Samsung NQ4 Gen3 processor is responsible for upscaling and digital image processing. It handles upscaling lower-resolution material to 4K very well. The picture is clear without looking artificial or overly sharp. The only rather specific drawback appears with very old material recorded at 480p or below. In such cases the TV can slightly crop the edges of the picture.

The processor also copes quite well with artefacts visible in lower bit-rate material, for example heavily compressed YouTube videos. The noise reduction function effectively smooths the image and reduces posterisation, but it operates quite aggressively. It can remove not only unwanted artefacts but also some fine detail, and even natural film grain. Wanting to preserve the source material as faithfully as possible, we decided not to use it. However, if someone prefers a clean, as-smooth-as-possible picture over retaining every detail, it may prove useful.

The TCL A400 Pro is equipped with a 144 Hz panel, but in practice we are most interested in its behaviour at 120 Hz. That is the frequency most consoles are limited to today, as well as many sports broadcasts and high-frame-rate content. At that rate the TV performs quite well. The sharpness of moving objects is really good, especially after properly configuring the motion smoothing. The "Motion Clarity" function is responsible for improving smoothness. Its settings include two sliders that let you tailor how the motion smoothing operates to your preferences, separately for lower and higher frame-rate material. This makes it possible to achieve both a more cinematic look and a noticeably smoother picture. Those who do not want to fiddle with manual configuration can use presets such as low, medium, high, cinema or nature.

Another major advantage of organic OLED panels is their excellent motion handling. Thanks to the pixels' virtually instantaneous response time, the Samsung S99H exhibits virtually no motion blur. Fast-moving objects do not produce visible halos or trailing outlines, so the television performs very well for both watching sport and gaming. One characteristic of OLED screens compared with LCDs, however, is the way they render low-frame-rate material. With very slow camera movement the image can appear noticeably more 'choppy'. This can, however, be fairly effectively mitigated using a frame-interpolation system. Samsung lets you adjust judder reduction and blur reduction separately, so it's easy to find a compromise between smoother motion and preserving the cinematic character of the content.

In terms of features for gamers the TCL A400 Pro performs brilliantly. The TV has practically everything you can 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-generation consoles and a PC. Another plus is the presence of the Game Bar, a special 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 also adjust the appearance and behaviour of some settings to suit your preferences. This solution 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 connectors out of the four available, and one of them also serves as eARC. In practice this means that if someone wants to connect two next-generation consoles and a soundbar, they may run into some limitations. In that scenario you will have to either swap devices or use additional equipment, such as an AV receiver or a soundbar with HDMI inputs. Even so, it is hard not to rate the A400 Pro very highly as a TV for gamers. The gaming feature set here is truly powerful.

The Samsung S99H is also a great TV for gamers. It offers almost every possible and useful feature... well, except for the obvious lack of Dolby Vision for the Xbox console. It's equipped with four full-bandwidth HDMI 2.1 ports that offer the full 48 Gbps. This lets you use VRR frame-rate synchronization and the automatic game mode (ALLM) without any problems. This year Samsung also has no issues properly supporting HGiG, so HDR setup on a console is quick and straightforward. Samsung's TVs are also known for interesting extras. In the Game Bar menu you'll find options to add an on-screen crosshair, enlarge the minimap or change the displayed image's aspect ratio (PC).

Particularly noteworthy is Samsung's Game Motion Plus feature. It's Samsung's proprietary motion-smoothing system that uses interpolation to increase smoothness in games. Input lag then rises to around 40 to 50 ms (depending on the strength of the setting), which is an excellent result compared with the competition. The system makes gameplay noticeably smoother. So if someone has their eye on a demanding game (e.g. GTA 6 😉) that runs on a console at only 30 frames per second, the S99H can display it much more smoothly than competing models.