Philips OLED820 vs TCL C8L / QM8L

When it comes to HDR quality, the Philips OLED820 uses the same class of WOLED panel found in its biggest rivals – the LG C5 and Samsung S90F. This means we can expect really solid results. This year, mid-range OLED panels can exceed the threshold of a thousand nits, and the tested model reaches around 1300 nits in some films. This is an outstanding result, allowing the director's vision to be conveyed with immense precision, as this is the brightness range in which contemporary productions are mastered. Of course, there are situations where even the OLED820 has to compromise. Full-screen scenes filled with white, like those in the film The Meg, can drop brightness to 400–500 nits, which clearly weakens the effect. This is a characteristic of OLED technology that has yet to be fully eliminated. Despite this limitation, it is hard not to appreciate the HDR in this model – high luminance and a wide DCI-P3 colour gamut coverage of 99% make the image simply look fantastic.

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 colour reproduction in the factory settings really surprised us, and positively so. The Philips OLED820, switched to Filmmaker mode, immediately showed that it was quite well tuned in terms of colour. The white balance was relatively accurate, though there was a slight deficiency in the blue hue, which occasionally gave the image a slightly yellowish tint. However, this is not a flaw that particularly detracts from everyday viewing. A bigger issue arose with the brightness characteristics. The gamma curve clearly deviated from the ideal, with the line below the expected values, causing the image to be excessively brightened, and the colours looked as if they were covered with a light milky filter. This effect was also noticeable in tests using the Colour Checker pattern, where more pronounced errors appeared.

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.

After calibration, both the Filmmaker mode and the gaming mode gained a lot. A slight adjustment of the white balance and an improvement in brightness characteristics produced excellent results in SDR content – the image looked almost perfect, natural, and very close to reference. In the case of HDR materials, the situation was similar, the colours were presented wonderfully, and it was hard to find anything to criticise. However, we noticed a certain feature, which we already pointed out when comparing scenes from the film Billy Lynn. The analysis of the EOTF curve showed that the television has a slight tendency to dim details in the blacks, so the darkest parts are not always displayed exactly as intended by the director. Nevertheless, the effect after calibration is stunning, and the OLED820 is emerging as one of the more interesting screens in its class. It just needs a little pampering, and there really is nothing to worry about.

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.

Fortunately, the earlier effects of the mentioned posterisation can be quite effectively mitigated. The "distortion reduction" function set to a medium level deals with unwanted colour banding, improving the smoothness of tonal transitions. It does happen that it works a bit too aggressively and also smooths out some details – such as minor skin imperfections of the actors – but nevertheless, it can be considered worth using without substantial compromises. The upscaling in the OLED820 also performs quite well. The test image with the model is exceptionally soft, sometimes even too much so, although this can be rectified by slightly boosting the sharpness in the picture menu – this is really a matter of individual preference. The absence of overscan issues with very low-resolution content is also commendable, meaning we don't have to worry that the image will be unnecessarily cropped.

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 fluidity of motion is an area where OLEDs always shine, and the Philips OLED820 confirms this rule. The panel itself offers a refresh rate of 144 Hz, which primarily benefits PC gamers, but even with standard television sources or consoles, where it operates at 120 Hz, the motion is fast, sharp and simultaneously smooth, without signs of blurring. This is thanks to the remarkable response time between pixels, which maintains image clarity in every dynamic scene. The manufacturer has also added its own smoother called "Motion Style". In the menu, we find two sliders – the first, responsible for fluidity, allows adjustments to the number of artificially added frames in films. This way, we can choose a raw, cinematic character with a distinctly visible film frame or a more theatrical image with smooth motion. The second slider is for motion blur reduction, particularly useful in sports broadcasts. Here, we definitely recommend setting it to the maximum value, as the effect is truly excellent.

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 Philips OLED820 is one of the most complete televisions for gamers. On board, we find practically everything one could expect: two HDMI 2.1 ports with full bandwidth of 48 Gbps (it's a shame there aren't four), variable refresh rate VRR, automatic game mode ALLM, support for Dolby Vision in games, and a good implementation of the HGiG mode. The television handles lower resolutions at 120 Hz with ease, so one can count on considerable flexibility when choosing different picture modes on the console. Philips also includes a Game Bar – a panel that allows changing picture modes, adding a crosshair, or previewing parameters. Although it looks rather clunky and is less polished than that of the competition, it does its job. In practice, therefore, the OLED820, in addition to a full set of four HDMI 2.1 ports, offers nearly everything a gamer could need.

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.