LG UT8100 (IPS) vs TCL A400 PRO

The LG UT8100 television unfortunately does not meet expectations in the HDR effect category. A peak brightness of only 300 nits on the luminance chart is well below the required value to fully enjoy HDR effects. In practice, the image resembles SDR quality more than true HDR, which is particularly evident in demanding high-contrast scenes. The coverage of the DCI-P3 colour palette is only 82%, which further limits the ability to present vibrant and rich colours. Instead of impressive visual experiences, we receive a muted and washed-out image. For those looking for a television to fully utilise HDR content, the LG UT8100 model turns out to be quite disappointing.

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 Filmmaker Mode on LG UT8100, while theoretically the best for watching movies, has significant issues. The biggest problem is the white balance – drops in blue cause a noticeable yellowing of the image, visible in both HD and 4K content. These issues are confirmed by measurement results in the Colour Checker test, which indicate significant deviations in colour reproduction.

In terms of brightness characteristics, both HD and 4K content exhibit a large tonal boost. The gamma curve in both cases remains well below the reference value of 2.4, which leads to excessive brightening of darker elements of the image. A similar problem is evident in the EOTF curve – in the case of 4K content, the TV struggles to manage brightness correctly, resulting in issues with screen brightness. This means the factory settings of this model require significant adjustment to achieve better picture quality.

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.

After calibrating the Filmmaker Mode, the gamma has been aligned to practically perfect, reference values, which has significantly improved the overall tonal characteristics in HD content. 4K HDR content also looks better, although some issues are still visible at the extreme ends of the graph, where the curve deviates from the ideal. The EOTF curve performs worse since the TV struggles to maintain the correct brightness values. As a result, the image in some scenes may be too bright or slightly dim, which stems from the device’s design. Nevertheless, the calibration brought significant improvement, particularly for HD content, where the tonal balance and colour reproduction are now at a much higher level.

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.

The fluidity of tonal transitions is also correct, although the effect depends on the settings. The update improved the operation of the smooth gradation function, smoothing transitions better than before, but introduced minor issues with detail loss, e.g. on textures.

Image scaling on LG UT8100 performs very well. The image presents itself decently, with no major issues regarding edge aliasing. Details are preserved at a satisfactory level, making materials of lower resolution look really solid on this television. As a result, users can enjoy watching older content without any noticeable defects in quality.

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.

LG UT8100, equipped with a 60 Hz panel, is particularly suited for those watching movies. The television offers the TruMotion system with a de-judder effect adjustment, which allows users to tailor the smoothness of the picture – from more choppy to exceptionally smooth, resembling a soap opera effect, depending on user preferences.

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.

LG UT8100 offers basic features for gamers, such as ALLM and Game Bar, which makes it easier to access settings. The TV also supports HGiG, improving picture quality in HDR games. Unfortunately, the lack of support for Dolby Vision and VRR limits the device's capabilities, as does the 60 Hz panel, which excludes support for 120 Hz resolution. This model is more suited for less demanding gaming applications.

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.