TCL A400 PRO vs Philips OLED811

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.

Philips OLED811 uses the new generation WOLED EX panels, also found in models like the LG C6 and Samsung S90H. After calibration we measured about 1500 nits, which is a very good result for an OLED TV. You can see that clearly in films and series. Flashes of light have the right punch, especially when they appear on a dark background. In those scenes the OLED811 can deliver really impressive HDR. Of course this doesn't mean you'll see that level of brightness in every shot. When the screen is filled with a large area of white or a wide explosion, brightness falls to around 600 nits. That's still a good result, but such scenes don't have the same impact as small bright elements on a dark background. That's a known limitation of OLEDs and the OLED811 is no exception.

Colours

Aside from HDR brightness, colours also matter and here Philips also performs very well. It covers almost the entire DCI-P3 gamut, which contains most of the colours used in HDR films and series. So you get rich reds and lush greens, and while watching it's hard to fault it in that regard. It looks a bit worse with the much wider BT.2020 gamut — its most saturated shades are already beyond the reach of this panel. There's also the issue of the white subpixel that the WOLED panel uses to help boost brightness. With very bright colours you can see a certain "washout": the colour is bright but loses some of its intensity. It's in exactly these situations that Samsung Display's QD-OLED panels have the advantage. In most films and series, though, this won't be something that immediately jumps out at you.

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 film mode on the Philips OLED811 is sensibly set up straight out of the box. Most colour errors remain minor in both SDR and HDR, so you can comfortably sit down to watch without adjusting the settings first. There are no large inaccuracies that would immediately distract from the film.

It’s not quite perfect, though. The white balance shows a slight lack of red relative to green, so whites and greys can have a faint greenish tint. It’s not a strong colour cast, but measurements clearly show it. There are also small luminance deviations in SDR: some parts of the image are slightly brightened, and the deepest tones aren’t always reproduced evenly. In HDR the TV stays much closer to the reference, although it occasionally lifts detail from the shadows. These are generally things that can be refined. The factory film mode provides a good starting point, and calibration will reveal how much more you can get out of it.

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.

After calibration the Philips OLED811 delivers an image very close to the reference. We managed to even out the white balance and remove the slight colour cast visible in the factory settings. ColorChecker errors for SDR and HDR fell to around 1 to 2, with many samples even below 1. That's a level at which differences from the reference are hard to spot with the naked eye. We also improved the gamma, with only a slight lift remaining in the brightest whites. In HDR the EOTF curve also stays close to the reference, although the TV still tends to slightly boost the brightness of small details, such as stars or subtitles. That gives the picture a bit of extra brightness that shouldn't be there, but otherwise it's hard to find fault. It was already good out of the box, and calibration allowed us to iron out most of the remaining issues.

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.

The OLED811 handles processing lower-quality material reasonably well, though it's far from perfect. The "Banding reduction" function helps smooth tonal transitions and on the low setting gives a pretty good effect. It doesn't remove banding between shades as effectively as similar solutions from some competitors, but at least it doesn't introduce new artefacts. It's a sensible setting for everyday viewing. Still, there's a bit of a letdown, because the MediaTek Pentonic 800 chipset used here can, in other manufacturers' hands, deal with the effects of heavy compression more effectively even at similarly low settings. A lot therefore depends on how a given manufacturer uses its capabilities.

We have a few more comments about the upscaling to 4K. There's plenty of detail, but overall the image looks rather soft. Edges are heavily smoothed, so the picture lacks some sharpness and clarity. You can partially correct this with the sharpness slider in the menu, though that will be extra edge enhancement rather than recovering detail. On the plus side, there's no overscan, and even with an SD signal the TV doesn't crop the edges of the picture.

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 OLED811 performs superbly. At 120 Hz, which is useful for console gaming and watching sport, the image remains clear and moving objects don't leave noticeable trails. The OLED's fast pixel response helps here. You can see it clearly in the UFO test, even on a dark background. There are also controls for motion smoothing. In movies you can adjust the strength of smoothing to your taste, from preserving a cinematic feel to much smoother motion. A separate blur-reduction control is useful for fast-paced content like live sports broadcasts.

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.

The OLED811 has almost everything you’d expect from a TV for gaming. It supports 120 Hz at Full HD, 1440p and 4K, and when connected to a PC it can reach up to 165 Hz. It also offers VRR to help avoid screen tearing when frame rates fluctuate, and ALLM, which automatically switches to game mode. So you don’t have to go into the settings every time you start your console.

Another plus is the properly working HGiG, which ensures that once HDR is set on the console the TV doesn’t apply its own changes to image brightness. The Game Bar is also available, letting you check signal parameters and quickly change settings useful while gaming. The list even includes Dolby Vision for games, but there’s a significant catch here, which you’ll read about below.