TCL C8L / QM8L vs LG OLED B6

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 LG B6 is a moderately bright OLED. After calibration it reaches about 800 nits, roughly 200 nits more than last year’s B5. That’s thanks to the new budget OLED SE panel from LG Display. In practice it simply gives a bit more headroom and makes HDR in many scenes look fuller than on last year’s lower-tier OLEDs. That doesn’t mean the B6 has no limits. In very bright shots, when a large part of the screen is strongly lit, brightness can drop below 400 nits. This behavior is typical for OLED TVs (especially those from this segment) and that’s when you see the biggest difference versus more expensive models. All things considered, we rate the B6’s results as really solid. It’s still not a TV for breaking brightness records, but the HDR effect is strong enough that you can really feel the step up from ordinary SDR in films.

Color gamut

Using the OLED SE panel has slightly affected wide color gamut coverage. Compared with last year’s model, results fell by a few percentage points. DCI-P3 reaches about 96%, and BT.2020 around 71%. That doesn’t mean the colors on the LG B6 are weak. In most movies and series they look lively, well saturated and simply pleasing to the eye. You only notice a difference in very bright, highly colorful scenes. Then colors lose some intensity compared with QD-OLED panels. This comes from the WOLED panel construction. Besides red, green and blue subpixels it also uses a white subpixel that helps boost brightness. It comes at a cost: at very high luminance some color is effectively “diluted” by the white light, so saturation of some colors can be slightly lower. In everyday use this isn’t a big issue, but you can notice it in the most demanding scenes.

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.

We tested the LG B6 in Filmmaker Mode, which is the best picture setting available right out of the box. ISF modes deliver very similar results, but in our tests we always stick to Filmmaker Mode for better comparison with other TVs. Each of those modes is, after all, a much better starting point than Vivid or Eco mode, where the picture is heavily boosted and noticeably less natural. With SDR content, the factory settings perform really well. Color errors are small, gamma behaves properly, and the image looks natural during ordinary viewing and does not seem overly "pumped up." It's a bit worse with HDR. When you play that kind of content you can quickly see that the white balance hasn't been set perfectly. Too much blue and red causes the image to shift toward a slightly pink tint. This is also confirmed by measurements of the color gamut and the ColorChecker, where samples clearly drift in that direction. It's not a flaw that completely ruins the picture, but you can notice it in HDR films. So people who care about the most faithful image should consider the calibration we describe later in the review.

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.

During calibration we focused primarily on HDR content, because that's where the factory settings required the biggest corrections. We didn't neglect SDR mode, though, which after adjustment was brought almost to perfection. Colors are very accurate and brightness is handled as it should be. The biggest improvement in HDR came from correcting the white balance. After removing the excess red and blue, the pinkish tint disappeared and the image became much more natural. Skin tones, whites and all colors that had been shifting toward magenta improved. After calibration most errors fell below a Delta E of 2–3, the threshold at which the average viewer stops noticing differences with the naked eye. The LG B6 can therefore deliver a very accurate image, especially for the manufacturer's entry-level OLED model.

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 B6 handles lower-quality sources very well. Much of the credit goes to effective digital image processing, which can mask some source imperfections without overly smoothing the whole scene. The feature "Smooth Gradation" proves particularly useful. It can significantly reduce posterization, which we mentioned earlier, especially in darker areas of the image. The safest choice remains Low or Medium. The function still effectively smooths harsh tonal transitions, but does not yet interfere too much with fine details. The most dedicated purists can, of course, leave it off. Upscaling to 4K also performs very well. Full HD and 720p content retain a good amount of detail, and the image is neither overly sharpened nor excessively blurred. Some limitations become noticeable only with very poor sources below 720p, where the smallest subtitles and fine elements are not always perfectly sharp, but this is true for almost every other TV on the market.

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.

One of the biggest advantages of OLED panels is their very fast pixel response time. This keeps the image sharp and prevents the visible smearing that often appears on LCD TVs. However, there is a downside. During slow camera pans, motion can look more choppy than on LCD screens, where the slower panel naturally masks some of that effect. Fortunately, on the LG B6 you can easily soften this with TruMotion. With the motion smoothing properly adjusted, you can achieve smoother motion without giving the picture an excessive soap-opera effect.

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.

LG OLED B6 offers a powerful set of advantages for gamers; it's simply a complete platform for PS5, Xbox Series X/S, or a solid PC. It has four full-size HDMI 2.1 ports with 48 Gbps bandwidth, so you can skip the annoying cable swapping when you want to connect several newer devices at once. We get the full suite of sync technologies – from classic VRR to G-Sync and FreeSync. The screen seamlessly matches the refresh rate to the frame output produced by the console or graphics card. Of course ALLM is included: the B6 automatically detects a running game and immediately cuts input lag to a minimum. HDR handling is also excellent. The TV supports Dolby Vision, and a properly implemented HGiG standard means that after an initial calibration in the console settings the picture won’t suffer from blown-out highlights or lost detail in bright areas. The cherry on top is the Game Bar. Instead of digging through the full menu during gameplay, one click lets you adjust shadow visibility, tweak selected settings, or simply check the display’s current operating mode. All of this makes the LG B6 a great choice for gamers.