LG OLED G4 vs TCL A400 PRO

LG G4 guarantees an incredibly vibrant HDR effect, placing the television firmly at the top of the rankings. The highest model in the manufacturer's 2024 portfolio, equipped with the second generation of microlens technology (MLA), has achieved a maximum brightness level of 1474 nits in real scenes. The only area where the product of the Korean manufacturer may fall short compared to LCD televisions with Mini LED backlighting is during a full-screen scene featuring a lot of white. If we were to disregard the latter scene, the average result would be even higher. It's also worth mentioning scenes with very fine details, where each one shone at full intensity, which is not as evident in non-OLED televisions. The combination of such brightness and wide coverage of the DCI-P3 color space ensures that HDR materials are more engaging than ever before.

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 best factory mode in terms of colour reproduction was "Filmmaker". This is the one we used during our tests. Let's check how its characteristics looked before the calibration process. Taking a closer look at the white balance first, we can notice a significant dominance of red and green colour. As a result, the image had a warm yellow tint. This is the kind of characteristic we usually observe in "Cinema", "Filmmaker", or similarly named modes. The effect of such a colour balance was clearly visible in both SDR and HDR content, which, after switching from "Standard" mode, was distinctly yellowed. Now let's move on to two graphs that are responsible for brightness characteristics, and consequently, image contrast. The first one (Gamma), representing materials with a standard colour palette, performed decently. For most of the time, the midtones and bright whites were represented very accurately, however, it noticeably lost the darkest details which blended into a black patch. On the other hand, HDR materials, represented by the EOTF curve graph, exhibited a significant drop in contrast due to a strong boost in brightness. There was also an issue with the colours themselves as seen on the "ColorChecker" graph since they were noticeably undersaturated.

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 manufacturer has been implementing extensive support for the calibration process in their LG televisions for many years. Therefore, we used 2- and 20-point grey scale adjustments along with an advanced CMS (Color Management System) and got to work. As you can see, thanks to the procedure carried out, each of the parameters has significantly improved. The use of tools has resulted in extremely beneficial effects, which include: studio colour reproduction, recovery of details in dark areas of the image, appropriate brightness characteristics, and proper colour saturation. Thus, we have maximised our approach to the reference image, or the one that the film director saw on the preview monitor. It is worth noting that the LG G4 televisions are the only ones that allow for even deeper intervention in image quality due to the capability to calibrate with 3D LUT matrices. However, this solution is recommended only for post-production or graphic studios.

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 tested television did not perform well with content rich in tonal transitions, resulting in a strong posterisation effect. However, there is a partial remedy for this ailment. The manufacturer has equipped the LG G4 with a smoothing system called "Gentle Gradation," which we can apply at three levels: Low, Medium, and High. Each of these options guarantees quite high smoothing effectiveness on bright colours, though low on darker ones. We recommend primarily using the first one due to the fact that the other two interfere with directorial intentions, removing film grain.

When watching lower-quality content, the efficiency of the television during upscaling is extremely important. The image from the tested television is sharp and clear. However, attention should be paid to the jagged edges of fine details and minor issues around characters, such as the creation of a halo effect, which occurs due to the sharpening imposed by the LG G4 even when the slider is set to the lowest value, which is 0. It is worth noting that this is a change in relation to the LG G3, which did not impose such strong image sharpening, even when the appropriate slider was set to position 0.

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 maximum refresh rate that we can set on the LG G4 is 144 Hz. Naturally, this is only possible by connecting the LG G4 to a very powerful PC. Otherwise, we will be operating at a maximum refresh rate of 120 Hz, which is recommended if we primarily want to watch sports or content with high motion dynamics. For those who require high fluidity of image, the manufacturer has implemented a multi-level motion smoother called "TrueMotion". It has been divided into two separate sliders that adjust the sharpness of moving images (De-Blur) and judder (De-Judder). Both sliders can be set in the range from 0 to 10, with each increment affecting the degree of smoothing, so everyone can find their sweet spot.

The LG OLED G4 panel features an average response time of 0.78 ms (which directly results from our measurements), allowing for an incredibly clear image, unattainable by LCD televisions, which have response times of even several milliseconds. This is clearly visible in the "UFO Test" images, showing the absence of any trailing blur behind the object. Furthermore, the LG OLED G4 test showed that the television offers the ability to precisely adjust motion smoothing functionality, allowing users to choose the ideal level of image interpolation. We particularly appreciated this during fast-paced action in video games, where the LG G4 performed exceptionally well, minimising any blurriness. Thanks to OLED technology, this model eliminates so-called ghosting, ensuring that the image remains sharp even in the most dynamic sports or movie scenes.

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.

The LG G4 television supports all features that make up the HDMI 2.1 standard. During testing, each feature activated without any issues, which allows us to consider the television as designed for gaming. Its performance will certainly be appreciated by both console users and those connecting the LG G4 to a computer. It’s also worth mentioning the proper implementation of the HGIG (HDR Gaming Interest Group) mode, which ensures that games mastered to brightness levels beyond the maximum luminance of the LG G4 will correctly map tones, keeping the game image true to the original.

A nice touch is the presence of a special GameBar that we can bring up at any moment to check game parameters, but most importantly, to change them quickly. More importantly, turning on VRR technology does not degrade contrast, which is often a problem in televisions with local dimming or Mini LED backlighting. Of course, this is thanks to the OLED panel itself, characterised by pixel self-emissiveness. As a journalistic note, we will only mention a slight grey flicker, which, however, is somewhat normal when VRR is enabled.

In summary, the LG G4, like practically all OLED televisions, is an ideal product for all kinds of gaming and online competitions. With full HDMI 2.1 ports with a complete bandwidth of 48 Gbit, features such as VRR, ALLM, G-Sync, FreeSync, or HDR Dolby Vision gameplay will bring a lot of joy.

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.