LG OLED G4 vs TCL C8L / QM8L

The LG G4 excels in delivering an incredibly vivid HDR experience, positioning it as one of the best models in its class. Equipped with second-generation Micro Lens Array (MLA) technology, it achieves a remarkable peak brightness of 1474 nits in real-world scenes. While it may not match Mini LED-backlit LCD TVs in full-screen white scenes, the overall performance is outstanding. The fine details in HDR content shine brightly, a distinct advantage of OLED technology over non-OLED displays. With this impressive brightness and wide DCI-P3 colour gamut coverage, HDR content is brought to life with unmatched engagement and immersion.

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.

Before calibration, the "Filmmaker" mode on the TV had a noticeable red and green colour dominance, resulting in a warm-yellow hue across both SDR and HDR content. This warm tone, typical of modes like "Cinema" and "Filmmaker," led to a yellowish cast that was evident when switching from the "Standard" mode.

Looking at the brightness characteristics, the Gamma chart showed decent performance for mid-tones and bright whites, but it struggled with the darkest details, which tended to merge into a black blob. HDR content, as represented by the EOTF curve chart, displayed a drop in contrast due to excessive brightness, which overshadowed fine details and negatively affected the overall image quality. Additionally, the "ColourChecker" chart revealed that colours were under-saturated, contributing to a less accurate and vibrant visual experience.

This provided a good foundation to build on, but calibration was needed to bring out the full potential of the "Filmmaker" mode and address these issues.

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.

The manufacturer has been offering extensive support for the calibration process in its LG televisions for many years. Therefore, we used 2- and 20-point grayscale adjustments along with an advanced CMS (Colour Management System) to optimise the display. As shown, the calibration procedure greatly improved each parameter. The results included studio-quality colour reproduction, enhanced detail in dark areas, corrected brightness characteristics, and accurate colour saturation. This led to a near-perfect match with the reference image—the one the film director saw on the preview monitor. It’s also worth mentioning that LG G4 televisions are unique in offering even deeper image adjustments through 3D LUT matrices, a feature primarily suited for post-production or graphics studios.

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.

The LG G4 does not perform well with materials rich in tonal transitions, leading to a pronounced posterization effect. However, the manufacturer has included a smoothing system called "Gentle Gradation," with three levels: Low, Medium, and High. These settings are effective at smoothing bright colours, though less so for darker tones. It is recommended to use the Low setting, as the higher levels can distort the director's intentions by removing film grain.

When it comes to upscaling lower-quality material, the television's performance is quite good, delivering a sharp and clear image. However, attention should be paid to the jagged edges of fine details and the occasional halo effect around figures. This occurs due to the sharpening imposed by the LG G4, even when the lowest setting is selected (0). This is a noticeable change from the LG G3, which did not apply such strong sharpening, even at setting 0.

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.

The LG G4 offers a maximum refresh rate of 144 Hz, achievable when connected to a powerful PC. For most users, however, the TV operates at a maximum of 120 Hz, ideal for watching sports or other content with fast motion. To improve image fluidity, the television includes the "TrueMotion" motion smoothing system, which features two separate sliders: De-Blur (for the sharpness of moving images) and De-Judder (for judder reduction). These sliders allow users to adjust the level of smoothing between 0 and 10, ensuring everyone can find the ideal setting.

With a response time of 0.78 ms, the LG G4 delivers exceptionally clear images, outperforming LCD televisions, which can have much slower response times. This results in no trailing blur behind moving objects, as shown in the "UFO Test." The TV also provides precise control over motion smoothing, which is especially beneficial during fast-paced video game sequences. Thanks to OLED technology, the G4 eliminates ghosting, ensuring a crisp and clear image even during the most dynamic sports or action scenes.

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 LG G4 TV supports all the features encompassed by the HDMI 2.1 standard, making it a gaming powerhouse. During testing, every feature activated seamlessly, ensuring a smooth experience for both console gamers and PC users. Notably, the HGIG mode (HDR Gaming Interest Group) is implemented correctly, allowing games mastered to brightness levels higher than the TV’s maximum luminance to map tones accurately, preserving the game’s original visual integrity.

A notable highlight is the dedicated GameBar, which can be accessed at any time to quickly check or adjust game settings. More importantly, enabling VRR (Variable Refresh Rate) does not compromise contrast—a common issue in TVs with local dimming or Mini LED backlighting. This is thanks to the OLED panel’s self-emissive pixels, which maintain consistent contrast. However, a slight grey flicker may appear when VRR is enabled, though this is standard across OLEDs.

In summary, the LG G4, like most OLED TVs, is ideal for gaming and online competitions. Its HDMI 2.1 ports offer a full 48 Gbps bandwidth, supporting features such as VRR, ALLM (Auto Low Latency Mode), G-Sync, FreeSync, and HDR Dolby Vision gameplay, ensuring an exceptional gaming experience.

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.