TCL C855 vs Philips OLED820

The TCL C855 delivers a highly varied HDR effect. At times, the television truly excels, while at other moments, it appears reminiscent of a low-end model equipped with FALD backlighting. Inconsistency is frequently found with this brand, so it didn’t come as a surprise. The first and last scenes, which feature large light elements, are nothing short of spectacular, boasting brightness levels of 1470 and 1820 nits, respectively. Such brightness can make viewers squint their eyes, allowing them to feel the extraordinary dynamism of the scene. It genuinely immerses the audience, creating a sensation of being inside the movie itself. However, the situation shifts dramatically when small or subtle elements with high luminance appear against a dark background. In these instances, the TCL C855 significantly reduces brightness to levels as low as 240 nits to mitigate halo effects. This reduction is disappointing, as it can make the movie appear as if it was not filmed in HDR. Despite these shortcomings, the HDR effect on the TCL C855 enhances the viewing experience during dynamic scenes, making it feel more engaging and allowing the viewer to feel part of the action. Even with smaller high-luminance elements, the television retains details without excessive dimming. Additionally, the TCL C855 adjusts image brightness according to scenes with rich detail, further enhancing viewing comfort.

When it comes to HDR quality, the Philips OLED820 uses the same class of WOLED panel that we find in its biggest competitors – LG C5 or Samsung S90F. This means we can count on truly solid performance. This year, mid-range OLED panels are capable of exceeding the threshold of a thousand nits, and the model tested reaches around 1300 nits in some films. This is an outstanding result that allows for an extremely precise depiction of the director's vision, as contemporary productions are mastered in such brightness ranges. Of course, there are situations where even the OLED820 has to compromise. Full-screen scenes flooded with white, like those in the movie The Meg, can drop brightness to 400–500 nits, which clearly weakens the effect. This is a characteristic of OLED technology that has not yet been fully eliminated. Despite this limitation, it is hard not to appreciate the HDR in this model – high luminance and wide coverage of the DCI-P3 color gamut at 99% make the picture simply look great.

The best factory mode for the TCL C855 is the "Film" setting, and all our tests were conducted using this mode. However, like many predefined modes, it has flaws that should be addressed to achieve an image closer to the producer's original vision. In our examination of the colour characteristics for both SDR and HDR materials, issues were found.

Focusing first on SDR content, there is a noticeable dominance of green in the white balance, which leads to an unpleasant greenish tint across the entire image. The gamma chart, crucial for image contrast, shows a significant deviation from the reference line marked at 2.4. Initially, there is a pronounced spike in the measured value, resulting in an over-contrasted image where details can merge into a dark blob. This condition persists for nearly 20% of the chart before it dips below the reference line, causing the image to brighten and resulting in a substantial drop in contrast.

In HDR materials, the factory mode performs somewhat better; the white balance appears more balanced overall, although the green tint resurfaces in the latter half of the spectrum. When we look at the Electro-Optical Transfer Function (EOTF) curve—unlike gamma, which reflects contrast—we identify two main errors: the darkest scenes are too dark, while the brightest ones become overexposed. This discrepancy was evident in our review of the scene from the movie "Pan," further illustrating the TCL C855's HDR performance issues.

The color 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 color. The white balance was relatively accurate, though with a slight lack in the blue hue, which sometimes gave the image a slightly yellowish tint. However, this is not a flaw that particularly interferes with everyday viewing. A larger problem arose with the brightness characteristic. The gamma chart clearly deviated from the ideal, with the line being below the expected values, causing the image to be overly brightened, and the colors 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.

TCL, like most manufacturers, offers advanced calibration tools within its televisions. These include both 2-point and 20-point adjustments for grayscale, as well as a comprehensive colour management system. As a result, we achieved impressive results in SDR materials, bringing the image significantly closer to the reference standard. We successfully eliminated both the green tint and the gamma issue, although a slight "kink" at the very beginning of the gamma curve still persists.

In contrast, the situation with HDR materials was less favourable, as the TCL C855 did not allow for precise modelling. We were only able to make minor adjustments to the EOTF curve while significantly enhancing the overall colour accuracy. This limitation suggests that while calibration tools are effective, they may require further refinement for optimal HDR performance.

After calibration, both the Filmmaker mode and the game mode gained quite a lot. A slight adjustment of the white balance and an improvement in brightness characteristics resulted in excellent outcomes for SDR content – the image looked almost perfect, natural and very close to the reference. In the case of HDR materials, the situation was similar; the colors looked stunning and it was hard to find anything to criticize. However, we noticed a certain feature that we had already pointed out when comparing scenes from the movie Billy Lynn. An analysis of the EOTF curve revealed that the television has a slight tendency to dim details in the blacks, which means that the darkest sections are not always displayed exactly as the director intended. Nevertheless, the effect after calibration is remarkable, and the OLED820 stands out as one of the more interesting screens in its class. It just needs a little bit of fine-tuning, and there's really nothing to be afraid of.

Once again, we will take a look at the function of smoothing tonal transitions, but this time also image scaling. The latter is particularly important when watching materials of lower quality, such as some television programs or older films. We will focus on the function responsible for tonal transitions. Interestingly, just like in the scenes from the previous test where it performed excellently and smoothed out practically all the inconsistencies, here it had issues. Using the menu responsible for the operation of this function, we found that no setting—even the strongest—was helpful.

Image scaling in TCL C855 is defined as one of the best we have had the opportunity to test so far. The image is sharp, but in a way that could be described as natural to our eye. Even small, fine branches do not have jagged edges, and there is no white halo around figures, a characteristic of weaker scaling systems.

Fortunately, the earlier effects of the aforementioned posterization can be quite effectively mitigated. The "distortion reduction" feature set to medium handles unwanted color banding, improving the smoothness of tonal transitions. It does happen, however, that it works a bit too aggressively and smooths out some details – such as minor skin imperfections of the actors – but despite this, it can be considered worth using without major compromises. The upscaling in the OLED820 also performs well. The test image with the model is exceptionally soft, sometimes even too much so, although this can be alleviated by slightly increasing the sharpness in the picture menu – it’s a matter of personal preference. The lack 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.

The maximum refresh rate you can set on the TCL C855 is 144 Hz. Naturally, this is only possible after connecting the TCL C855 TV to a very powerful PC. Otherwise, we will be operating at a maximum refresh rate of 120 Hz, which is recommended if we want to watch primarily sports or materials with a lot of motion dynamics. For those who require high image fluidity, the manufacturer has implemented a multi-stage motion smoother. It is divided into two separate sliders which control the sharpness of moving images (Motion Blur Reduction) and flicker (Flicker Reduction). Both sliders can be adjusted from 0 to 10, with each level affecting the degree of fluidity, so everyone can find their sweet spot. We present a setting that allows for slight smoothing without the soap opera effect. The matrix of the TCL C855 features a very good response time. This is particularly important since VA panels often struggle with the so-called ghosting effect, where a black halo can be observed behind a fast-moving object. where a black halo can be observed behind a fast-moving object.

Motion fluidity 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 will mainly benefit PC gamers, but even with standard television sources or consoles, where 120 Hz is used, the motion is fast, sharp, and simultaneously smooth, without traces of ghosting. This is thanks to the outstanding response time between pixels, which ensures the image retains clarity in every dynamic scene. The manufacturer has also added its own smoothing feature called "Motion Style." In the menu, we find two sliders – the first, responsible for fluidity, allows us to adjust the amount of artificially added frames in movies. This way, we can choose a raw, cinematic character with a clearly visible film frame or a more theatrical image with smooth motion. The second slider is for reducing blurring, especially useful in sports broadcasts. Here, we definitely recommend setting it to the maximum value, as the effect is truly excellent.

The TCL C855 TV has fully-featured HDMI 2.1 ports, boasting a full bandwidth of 48 Gb/s. During our testing, we confirmed the seamless operation of all functions included in this connection standard. As highlighted, all checkboxes are illuminated in green, a feature that will undoubtedly be appreciated by gamers, whether on consoles or those using the TV as a computer monitor. Additionally, the TCL C855 supports both AMD FreeSync and NVIDIA's G-Sync, which can be easily activated in the graphics card settings. Those with powerful configurations can feed a 144 Hz signal to the C855, which handles this effortlessly. It is also worth noting the implementation of the HGIG mode, which can be excessively bright due to the shortcomings of the "Game" mode, making proper configuration on the screen challenging. Fortunately, the TV excels with the Dolby Vision format.

TCL, as one of the pioneering manufacturers, has equipped its televisions with a special GameBar, allowing for extensive adjustment of settings "on the fly" without the need to exit the game. This feature includes options like an additional crosshair grid, black level correction, and settings designed for individuals with disabilities. The image showcases the next generation of this solution.

In summary, the TCL C855 TV is an ideal choice for those seeking a screen for all forms of electronic gaming. With comprehensive features supporting such entertainment, it provides an extremely engaging experience. It is also important to emphasise that it maintains very low input lag, regardless of the selected settings, including when using the Dolby Vision HDR format.

Philips OLED820 is one of the most complete televisions for gamers. It practically has everything you could expect: two HDMI 2.1 ports with full bandwidth of 48 Gbps (too bad 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 also handles lower resolutions at 120 Hz without any issues, so you can count on great flexibility when choosing different picture modes on the console. Philips also adds Game Bar – a panel that allows you to change picture modes, add a crosshair, or view parameters. Although it looks quite clunky and is less polished than that of the competition, it serves its purpose. In practice, therefore, the OLED820, besides having a full set of four HDMI 2.1 ports, offers almost everything a gamer might need.