Philips OLED820 vs TCL A400 PRO

When it comes to HDR quality, the Philips OLED820 uses the same class of WOLED panel found in its biggest rivals – the LG C5 and Samsung S90F. This means we can expect really solid results. This year, mid-range OLED panels can exceed the threshold of a thousand nits, and the tested model reaches around 1300 nits in some films. This is an outstanding result, allowing the director's vision to be conveyed with immense precision, as this is the brightness range in which contemporary productions are mastered. Of course, there are situations where even the OLED820 has to compromise. Full-screen scenes filled with white, like those in the film The Meg, can drop brightness to 400–500 nits, which clearly weakens the effect. This is a characteristic of OLED technology that has yet to be fully eliminated. Despite this limitation, it is hard not to appreciate the HDR in this model – high luminance and a wide DCI-P3 colour gamut coverage of 99% make the image simply look fantastic.

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.

The colour reproduction in the factory settings really surprised us, and positively so. The Philips OLED820, switched to Filmmaker mode, immediately showed that it was quite well tuned in terms of colour. The white balance was relatively accurate, though there was a slight deficiency in the blue hue, which occasionally gave the image a slightly yellowish tint. However, this is not a flaw that particularly detracts from everyday viewing. A bigger issue arose with the brightness characteristics. The gamma curve clearly deviated from the ideal, with the line below the expected values, causing the image to be excessively brightened, and the colours looked as if they were covered with a light milky filter. This effect was also noticeable in tests using the Colour Checker pattern, where more pronounced errors appeared.

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.

After calibration, both the Filmmaker mode and the gaming mode gained a lot. A slight adjustment of the white balance and an improvement in brightness characteristics produced excellent results in SDR content – the image looked almost perfect, natural, and very close to reference. In the case of HDR materials, the situation was similar, the colours were presented wonderfully, and it was hard to find anything to criticise. However, we noticed a certain feature, which we already pointed out when comparing scenes from the film Billy Lynn. The analysis of the EOTF curve showed that the television has a slight tendency to dim details in the blacks, so the darkest parts are not always displayed exactly as intended by the director. Nevertheless, the effect after calibration is stunning, and the OLED820 is emerging as one of the more interesting screens in its class. It just needs a little pampering, and there really is nothing to worry about.

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.

Fortunately, the earlier effects of the mentioned posterisation can be quite effectively mitigated. The "distortion reduction" function set to a medium level deals with unwanted colour banding, improving the smoothness of tonal transitions. It does happen that it works a bit too aggressively and also smooths out some details – such as minor skin imperfections of the actors – but nevertheless, it can be considered worth using without substantial compromises. The upscaling in the OLED820 also performs quite well. The test image with the model is exceptionally soft, sometimes even too much so, although this can be rectified by slightly boosting the sharpness in the picture menu – this is really a matter of individual preference. The absence of overscan issues with very low-resolution content is also commendable, meaning we don't have to worry that the image will be unnecessarily cropped.

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 fluidity of motion is an area where OLEDs always shine, and the Philips OLED820 confirms this rule. The panel itself offers a refresh rate of 144 Hz, which primarily benefits PC gamers, but even with standard television sources or consoles, where it operates at 120 Hz, the motion is fast, sharp and simultaneously smooth, without signs of blurring. This is thanks to the remarkable response time between pixels, which maintains image clarity in every dynamic scene. The manufacturer has also added its own smoother called "Motion Style". In the menu, we find two sliders – the first, responsible for fluidity, allows adjustments to the number of artificially added frames in films. This way, we can choose a raw, cinematic character with a distinctly visible film frame or a more theatrical image with smooth motion. The second slider is for motion blur reduction, particularly useful in sports broadcasts. Here, we definitely recommend setting it to the maximum value, as the effect is truly excellent.

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.

The Philips OLED820 is one of the most complete televisions for gamers. On board, we find practically everything one could expect: two HDMI 2.1 ports with full bandwidth of 48 Gbps (it's a shame there aren't four), variable refresh rate VRR, automatic game mode ALLM, support for Dolby Vision in games, and a good implementation of the HGiG mode. The television handles lower resolutions at 120 Hz with ease, so one can count on considerable flexibility when choosing different picture modes on the console. Philips also includes a Game Bar – a panel that allows changing picture modes, adding a crosshair, or previewing parameters. Although it looks rather clunky and is less polished than that of the competition, it does its job. In practice, therefore, the OLED820, in addition to a full set of four HDMI 2.1 ports, offers nearly everything a gamer could need.

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.