TCL C8L / QM8L vs TCL A400 PRO

In terms of HDR, the TCL C8L turns out to be a hellishly bright television – and I mean literally. On a synthetic chart of 5%, our measuring equipment indicated a result exceeding 4500 nits. This is a result that is downright cosmic, considering that reference director monitors, which we often refer to in our materials, typically operate around 4000 nits. Does this mean that the C8L breaks barriers and climbs to the technological peak of Mini-LED? Not exactly. Dry synthetic tests are one thing, and real movie images are another. In real, varied scenes, the C8L achieves a peak of around 1600 nits. This is still a very good result, ensuring a very high level of HDR dynamics, but also clearly lower than what the manufacturer boasts in the specifications. The trouble starts with very small flashes of light – then brightness can drastically drop to around 600 nits. The algorithm tries at all costs to maintain deep black and minimize halo effect, but it does so at the expense of HDR impact. This is perfect evidence that laboratory charts rarely correspond to what we ultimately see on the screen.

Huge applause is due for color reproduction, all thanks to the new generation of SQD (Super Quantum Dot) quantum dots. The coverage of the DCI-P3 palette reaches 97%, but the true jaw-dropper is the measurement of the extremely demanding BT.2020 space. The C8L achieves as much as 90% in it, placing it alongside today's top screens that boast RGB backlighting. Importantly, unlike some screens with Micro/Mini RGB backlighting, this effect is stable regardless of the scene displayed. Of course, one must remember that content mastered for such a wide gamut in films or series is still a rarity. However, the mere fact that the panel has such a "color reserve" deserves immense admiration.

The TCL A400 Pro is a moderately bright TV. Its peak brightness reaches about 600 nits. That level already allows for a real HDR effect and in many movies it does produce a noticeably more attractive picture than SDR. However, it is not a level that overwhelms by brightness alone. The A400 Pro is not one of those TVs that "attack" the viewer with a powerful flash in every dramatic scene. The biggest limitation is visible with small bright elements on a dark background. Due to rather aggressive control of the dimming zones, 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. That said, this is not done without reason. The A400 Pro does this to keep blacks as deep as possible and to limit haloing around bright objects. It's a deliberate compromise: the TV more often chooses deeper blacks over maximally bright, point-like highlights. On one hand this is understandable, especially with a limited number of dimming zones, but on the other hand you should be aware that the HDR effect will not always be as strong as the peak brightness alone would suggest.

On the plus side, the colors are worth noting. The PFS LED filter used here, marketed by the manufacturer as QLED, produces suitably saturated colors. Our measurements showed about 94% coverage of the DCI-P3 gamut and about 74% of BT.2020, which is a solid result for this class.

We tested the TCL C8L in the best factory picture mode available in this TV’s menu for image fidelity. That, of course, is Filmmaker Mode, which appeared in this brand’s software relatively recently (a year ago in the "K" series). Thanks to it, an average user can get a pretty good color reproduction straight out of the box, although it is certainly not a perfectly tuned mode. Looking at the factory white balance of our unit, both in SDR and HDR material, the red component was clearly lacking, which made the image noticeably cooler and caused a slight shift toward bluish-green tints. The issue of brightness management is also ambiguous, as we mentioned earlier. While for SDR content the gamma linearity is actually correct and holds steadily at the reference value of 2.4, in HDR things look much worse. Tracking the EOTF curve clearly shows the TV has a significantly boosted brightness across the range, which can make the final image overly bright and inconsistent with the creators’ intent, and that in a mode that by definition should avoid that. Of course, like every sample in our lab, this one also underwent professional calibration, and its results are shown below.

As standard, we carried out color measurements in the best-calibrated mode, Filmmaker Mode, the one that is supposed to be closest to the creators’ intent. The A400 Pro, of course, also offers other picture modes, but in practice they suffer from much larger color errors and alter the image character more strongly. We won’t go into those modes in detail in this part of the test. So how does the factory color reproduction perform? In short: really very well. In fact, looking at our measurement results, it’s excellent. Both the white balance and the luminance response were set surprisingly precisely. The errors were so small that during testing we genuinely rubbed our eyes in disbelief. Such good out-of-the-box settings don’t happen often, even in TVs operating in Filmmaker Mode. All the more reason to praise TCL, because the A400 Pro right out of the box can produce an image very close to how the source material should look. The results were so good that you could easily think someone had already paid extra attention to that unit and tried to calibrate it.

Our nitpicking really comes down to just one thing. In SDR content the image was slightly brighter than the reference for a dark room, because the factory gamma was set closer to 2.3 than to 2.4. It’s not a big error and most viewers probably won’t even notice it.

However, it should be noted that we’re talking about our specific review sample. With factory colors there can always be some variation between units, production batches, or screen sizes. So we don’t assume that every A400 Pro will look identical straight out of the box.

As you can see, the results of a professional calibration of the TCL C8L are really promising, thanks to the extensive adjustment tools the manufacturer put at our disposal in the menu. Above all, we were able to completely correct the white balance — we eliminated the red deficiency, so the image finally stopped drifting toward unwanted cool tones. After that adjustment, errors in the ColorChecker test fell to near-reference levels, regularly landing below a Delta E of 2, which is below the threshold of human perception.

If the test patterns look this perfect, you might ask: why then the lower final score in this category? The answer lies in the brightness management discussed earlier. Although the menu includes sliders that let you precisely straighten the EOTF curve on synthetic signals, when confronted with actual movie material (I recommend enabling the EOTF filter when watching movies), you can see that in most scenarios the TV still reacts to HDR metadata its own way. As a result, the picture can be slightly over-brightened and not faithful to the creators' intent, and it was precisely this lack of consistency with real films that cost the C8L a few points.

Despite its excellent factory tuning, we couldn't resist checking how the TCL A400 Pro would respond to a professional calibration. Since the starting point was so good, we were even more curious whether we could squeeze even more out of this TV. And here we have to boast: we managed to bring our unit to absurdly low color errors. Results below 1 are something you don't see every day, even on very good TVs. Such results are more often associated with professional reference monitors than with a lifestyle TV for the living room. In terms of white balance and color reproduction, the A400 Pro after calibration simply performed outstandingly. The only thing we can pick at after a deeper analysis concerns the brightness behavior. The TV can manipulate luminance levels depending on the content being displayed, and quite often the image is a bit darker than it should be according to the standard. This most likely stems from the way the Mini-LED backlight and local dimming algorithms work in this model. However, that doesn't spoil the overall impression, because in terms of color precision alone the A400 Pro after calibration reached a level we really didn't expect.

This year the C8 series and higher models received probably the biggest and most anticipated upgrade in TCL’s history, and it specifically concerns digital image processing. The C8L is the lowest-end model in the manufacturer's lineup to be equipped with the latest flagship chip, the MediaTek Pentonic 800 (listed in the menu as MT9655). Thanks to its processing power, the feature called "Gradual Smoothing" finally works as it should. The algorithm effectively eliminates unwanted posterization (ugly tonal transitions/color banding), doing so intelligently enough that it does not degrade the sharpness of other details.

The processor also handles upscaling lower-resolution content to 4K very well. Although evaluating this element can be mostly academic, because the differences between today's TVs in this class are very subtle. The most important takeaway is that TCL finally has nothing to be ashamed of compared to the competition.

Digital video processing is unfortunately one of the weaker points of the TCL A400 Pro. That doesn't mean the TV performs badly, but it's hard to call it anything clearly above standard. The upscaling itself is adequate: edges are smoothed fairly well, the image doesn't look overly sharp or pixelated, and lower-quality content can be watched without major discomfort. At the same time the overall look is slightly soft and it lacks the precision that the best image processors in more expensive TVs can deliver.

Much worse, however, is its handling of tonal transitions caused by heavy compression. TCL equipped the A400 Pro with a "Gradual Smoothing" feature that in theory should reduce visible color banding and artifacts in lower-quality content. In practice 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's best to leave this feature off. The A400 Pro handles basic image scaling decently, but if you often watch heavily compressed content with visible posterization, this model won't be one of the best choices.

The TCL C8L is equipped with a fast panel that has a native 144 Hz refresh rate. That spec will be most appreciated by demanding PC gamers, while most users, who rely on consoles or TV broadcasts, will use a steady 120 Hz. It is at 120 Hz that motion processing algorithms handle image rendering for movies, series, and sports. In the TV’s menu you’ll find a "Motion Clarity" option that lets you adjust the motion smoothing to your preferences. The algorithms handle cinematic material at 24 or 30 frames per second (fps) as well as dynamic sports broadcasts at 50 or 60 fps, maintaining appropriate smoothness.

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 used by most consoles today, as well as many sports broadcasts and high-frame-rate content. In this range the TV performs quite well. Motion clarity is really good, especially after properly configuring the motion smoothing. The "Motion Clarity" feature improves smoothness. Its settings include two sliders that let you tailor the motion smoothing to your preferences — separately for lower- and higher-frame-rate material. That way you can achieve either a more cinematic look or a noticeably smoother picture. If you don't want to tweak settings manually, you can use presets such as low, medium, high, cinema, or nature.

For gamers – especially for those with powerful PCs and several consoles at the same time – the TCL C8L is a true beast. It’s the first model in the manufacturer’s lineup equipped with four full HDMI 2.1 ports with a maximum bandwidth of 48 Gbps. This is directly thanks to the new Pentonic 800 processor we wrote about earlier. Additionally, the TV seamlessly supports virtually every gaming feature. It has an automatic game mode (ALLM) that reduces latency to minimal levels and full frame synchronization (VRR) operating in an impressive range of up to 288 Hz. We’re also talking about standards like G-Sync or FreeSync from Nvidia and AMD. When it comes to image display standards, there are also no compromises: the C8L offers complete support for HDR formats in games, including gaming Dolby Vision and the HGiG profile. All of these features can be conveniently managed from a very readable game bar (Game Bar), which we can customize according to our preferences. From a purely gaming perspective, there really isn’t anything to complain about in the C8L – well, maybe aside from the previously mentioned slight ghosting. But other than that? It’s an unflawed machine for gamers.

When it comes to features for gamers, the TCL A400 Pro performs excellently. The TV has practically everything you can expect from a gaming TV today: 4K support at high refresh rates, VRR, ALLM, correct implementation of HDR formats in games, including Dolby Vision, and HGiG. Because of that it works well with both next-gen consoles and PCs. Another plus is the inclusion of a Game Bar, a special panel with the most important settings for gamers. From it you can quickly check basic signal information, refresh rate, and active features, and also adjust the look and behavior of some settings to your own preferences. This is 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 complain about 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 functions as eARC. In practice this means that if someone wants to connect two next-gen consoles and a soundbar, they may hit some limitations. In that scenario you'll have to either swap devices or use extra equipment, for example an AV receiver or a soundbar with HDMI inputs. Despite this, it's hard not to rate the A400 Pro very highly as a gaming TV. The gaming feature set here is really powerful.