LG OLED G4 vs TCL C8L / QM8L

LG G4 guarantees an incredibly vivid HDR effect, placing the television among the very best. The equipment of the highest model in the producer's 2024 portfolio with the second generation of micro-lens technology (MLA) has achieved a maximum brightness level of 1474 nits in real scenes. The only area where the product from the Korean manufacturer may lag behind LCD televisions with Mini LED backlighting is during the full-screen scenes featuring a lot of white. If we disregard the latter type of scene, the average result would be even higher. It is also worth mentioning scenes with very fine details, where each one shines at full intensity, which is not as evident in non-OLED televisions. The combination of such brightness and wide coverage of the DCI-P3 palette makes HDR materials more engaging than ever before.

In terms of HDR, the TCL C8L turns out to be a hellishly bright television – quite literally. On a synthetic test pattern sized at 5%, our measurement equipment indicated a result exceeding 4500 nits. This is a truly astronomical result, considering that reference monitors used by directors, 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 quite. Dry synthetic tests are one thing, while real cinematic images are another. In real, varied scenes, the C8L peaks at around 1600 nits. This is still a very good result, ensuring a very high level of HDR dynamics, but it is also clearly lower than what the manufacturer boasts in the specifications. The problems begin with very small bursts of light – at that point, brightness can drastically drop to around 600 nits. The algorithm tries at all costs to maintain deep blacks and minimise the halo effect, but this comes at the expense of HDR impact. This is perfect evidence that laboratory test patterns rarely align with what we ultimately see on the screen.

However, huge praise is due for colour reproduction, thanks to the new generation of SQD (Super Quantum Dot) quantum dots. The DCI-P3 colour gamut coverage reaches 97%, but the truly jaw-dropping measurements come from the extremely demanding BT.2020 space. The C8L achieves an impressive 90% in this space, placing it alongside today's top screens equipped with RGB backlighting. Importantly, unlike some screens with Micro/Mini RGB backlighting, this effect is stable regardless of the scene displayed. Of course, it’s worth remembering that content mastered for such a wide gamut in films or series is still rare. However, the very fact that the panel has such a "colour reserve" deserves tremendous admiration.

The best factory mode in terms of colour reproduction was "Filmmaker". This was the one we used during our tests. Let's check how its characteristics looked before the calibration process. Looking closely at the white balance first, we can notice a significant dominance of red and green. As a result, the image had a warm yellowish hue. Such characteristics are typically observed in "Cinema", "Filmmaker" or similarly named modes. The effect of this colour balance was clearly visible in both SDR and HDR content, which after switching from "Standard" mode appeared distinctly yellow. Now, let's move on to two graphs that are responsible for the brightness characteristics and consequently the contrast of the image. The first one (Gamma), representing materials with a standard colour palette, performed decently. For most of the time, midtones and bright whites were reproduced very accurately; however, it noticeably lost the darkest details, which merged into a black blob. Conversely, HDR materials, represented by the EOTF curve graph, exhibited a significant drop in contrast due to a strong boost in brightness. The colours themselves also posed a problem, as can be seen on the "ColorChecker" graph, since they were noticeably under-saturated.

We tested the TCL C8L in the best factory mode available in the TV’s menu for image fidelity. That’s of course Filmmaker Mode, which only arrived in this brand’s software relatively recently (a year ago in the "K" series). It allows the average user to achieve quite decent colour reproduction straight out of the box, though it is certainly not perfectly tuned. Looking at the unit’s out-of-the-box white balance — in both SDR and HDR material — the red component was clearly lacking, which made the image noticeably cooler and slightly shift towards blue‑green tints. The issue of brightness management also looks ambiguous, as we mentioned earlier. While the gamma linearity in SDR content is really good and stays steadily at the reference value of 2.4, the situation in HDR is much worse. Tracking the EOTF curve clearly shows the TV has a noticeably boosted brightness across the entire range, so the final image can be excessively bright and inconsistent with the creators’ intent, and this is in a mode that by definition should avoid that. Of course, as with every sample in our lab, we subjected this one to professional calibration, and you can find the results below.

The manufacturer has implemented extensive support for the calibration process in its LG televisions for many years. We therefore used 2- and 20-point greyscale adjustments, as well as an advanced CMS (Colour Management System), and got to work. As you can see, thanks to the procedure carried out, each parameter has significantly improved. The use of tools allowed for the achievement of extremely beneficial effects, which include: studio colour reproduction, recovery of details in dark areas of the image, appropriate brightness characteristics, and suitable colour saturation. This brings us as close as possible to the reference image, which is what the film director saw on the preview monitor. It is worth noting that the LG G4 televisions alone allow for even deeper intervention in image quality thanks to the ability to calibrate with 3D LUTs. However, this is a solution recommended only for post-production or graphic studios.

As you can see, the results of a professional calibration of the TCL C8L are truly promising, thanks to the comprehensive calibration controls the manufacturer has provided in the menu. Above all, we managed to fully correct the white balance, eliminating the red deficiency, so the image finally stopped drifting into unwanted cool tones. After that adjustment, the errors in the ColorChecker test fell to near-reference values, consistently sitting below a Delta E threshold of 2, i.e. below the visibility threshold for the human eye.

If test patterns look so perfect, you may ask us why the final score in this category is lower. The answer lies in the brightness management described earlier. Although the menu includes sliders that let you precisely straighten the EOTF curve on synthetic signals, when faced with real film material (I recommend enabling the EOTF filter when watching films), it becomes clear that the TV, in most scenarios, still responds to HDR metadata in its own way. As a result, the picture can be slightly over-bright and not faithful to the filmmakers' intent, and it is precisely for this lack of consistency with real films that we had to take a few points off the C8L's score.

The tested television did not perform particularly well with materials rich in tonal transitions, as a result of which we could observe a strong posterisation effect. However, there is a partial remedy for this issue. 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 a high effectiveness of smoothing on light colours, although it is low on darker ones. We recommend primarily using the first one, as the other two interfere with the director's intentions by removing film grain.

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

This year the C8 series and the higher-end models have probably received the biggest and most eagerly awaited upgrade in TCL’s history, and it concerns digital picture processing. The C8L is the entry-level model in the manufacturer's line-up that has been equipped with the latest flagship chip MediaTek Pentonic 800 (listed in the menu as MT9655). It is thanks to its computing power that the feature called "Gradual Smoothing" finally works as it should. The algorithm effectively removes unwanted posterization (ugly tonal transitions / colour banding) from the image, 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 assessing this element can be largely 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 with the competition.

The maximum refresh rate that we can set on the LG G4 is 144 Hz. Naturally, this is only possible when the LG G4 is connected to a very powerful PC. Otherwise, we will operate 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 requiring high image fluidity, the manufacturer has implemented a multi-level motion smoother called "TrueMotion". This 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 level affecting the degree of smoothness, allowing everyone to find their golden mean.

The LG OLED G4 panel features an average response time of 0.78 ms (as directly derived from our measurements), enabling an incredibly clear image, unattainable by LCD televisions, which can have response times of several milliseconds. This is perfectly illustrated by the images from the "UFO Test", which show no trailing blur behind the object. Moreover, the LG OLED G4 test revealed that the television offers the ability to precisely adjust the motion smoothing function, allowing users to select the ideal level of image interpolation. We particularly appreciated this during fast-paced actions in video games, where the LG G4 performed exceptionally well, minimising any blurring. Thanks to OLED technology, this model eliminates so-called ghosting, ensuring that the image remains sharp even in the most dynamic sporting or cinematic scenes.

The TCL C8L is equipped with a fast panel with a native refresh rate of 144 Hz. This specification will be most appreciated by demanding PC gamers, while most users, who rely on consoles or TV broadcasts, will make use of a stable 120 Hz. It is at 120 Hz that the motion-processing algorithms take care of image processing (in films, series and sports). In the TV menu you'll find a "Motion Clarity" tab that allows you to tailor the motion smoothing to your own preferences. The algorithms cope well with both cinematic productions at 24 or 30 frames per second and with fast-paced sports broadcasts at 50 or 60 frames per second, ensuring appropriate smoothness.

The LG G4 television supports all the features that make up the HDMI 2.1 standard. During testing, each of them activated without the slightest problem, which allows us to consider the television as designed for gaming. Their functionality will surely be appreciated by both console users and those connecting the LG G4 to a computer. It is also worth mentioning the correct implementation of the HGIG (HDR Gaming Interest Group) mode, which ensures that games mastered to brightness levels exceeding the maximum luminance of the LG G4 will correctly map tones, and the game's visuals will remain true to the original.

A nice touch is the existence of a special GameBar, which we can call up at any moment to check game parameters, but most importantly, to change them quickly. More importantly, enabling VRR technology does not degrade contrast, which is very common in televisions that feature local dimming or Mini LED backlighting. Of course, this is thanks to the OLED panel itself, characterised by pixel self-emission. As a matter of editorial obligation, we will only mention a slight grey flicker, which is somewhat normal after enabling VRR.

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

For gamers – and especially for owners of powerful PCs and several consoles simultaneously – the TCL C8L is a true monster. It is the first model in this manufacturer's lineup to feature as many as four full HDMI 2.1 ports with a maximum bandwidth of 48 Gbps. This is directly attributable to the use of the new Pentonic 800 processor, which we discussed earlier. Additionally, the television seamlessly supports practically every gaming feature. We have 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. There's also talk of standards such as G-Sync or FreeSync from Nvidia and AMD. When it comes to display standards, there are no compromises either: the C8L offers complete support for HDR formats in games, including gaming Dolby Vision and the HGiG profile. We can conveniently manage all of these features from a very readable player bar (Game Bar), which we can personalise to our own preferences. From a purely gaming perspective, there's really nothing to fault the C8L on – well, maybe aside from the previously mentioned slight blurring. But other than that? It's a no-nonsense machine for gamers.