TCL C855 vs Philips OLED950

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.

OLED950 is a phenomenal TV for consuming HDR content, which is primarily due to the use of innovative Tandem OLED technology. With this technology, the screen is capable of generating astronomical brightness values, reaching over 2000 nits in movie scenes (on test screens). This is an outstanding result, placing the OLED950 model among the very top displays available on the market. However, it should be noted that there is a specific characteristic of this solution – at moments when full-screen bursts of light appear on the screen, the brightness can drop by as much as half. Nevertheless, it is worth emphasizing that values above 1000 nits on a full screen are still an outstanding result. This allows for HDR images to be displayed exactly as filmmakers would wish, maintaining the dynamics and impact of light scenes.

The use of Tandem OLED technology has also brought measurable benefits in terms of color reproduction, improving elements where traditional WOLED panels have had difficulties compared to QD-OLED competitors. In the case of the OLED950, the color gamut coverage is broader than in classic WOLED panels, reaching nearly 100% of the DCI-P3 space and a solid 82% of the demanding BT.2020 palette. Although these results still do not match the high achievements of QD-OLED panels, the difference diminishes during real-world usage. We cannot deny that in the vast majority of films, colors look simply fantastic on this model – they are saturated, vibrant, and full of depth.

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.

We tested the OLED950 model in Movie mode. Although it is theoretically the best and most faithful preset on this television, in practice, it proved to be not without flaws. Interestingly, in the unit we tested, the biggest challenge wasn't the white balance itself – although it did have a slight tendency to give the image a pinkish tint. The main problem lay in the way the television managed brightness, both in everyday SDR content and in demanding HDR scenes. Analysis of the gamma chart and EOTF curve leads to one key conclusion: the television excessively highlights brightness in the lower registers. This results in the image appearing less contrasty than the panel technology would allow. Details in dark areas that should remain perfectly black (characteristic of "OLED black") are simply unnecessarily highlighted and brightened. Fortunately, these errors can be corrected using the appropriate tools, so – as always – we proceeded with professional calibration.

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.

As can be seen, the OLED950 transforms into an absolutely phenomenal display after a professional calibration process, which without a shadow of a doubt can be placed in the same category as the best televisions currently available in the world. This equipment only needed a professional touch to show its full potential and eliminate factory shortcomings. The minimal errors in reproduction in Color Checker tests and the fidelity of the color palette speak for themselves. We are dealing with an almost perfect device here. A true window to the world, offering top-notch image quality.

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.

Upscaling

In terms of image scaling, the proprietary P5 processor performs just as well as in most models from this manufacturer. Lower resolution content takes on a very soft and plastic character. Such a presentation will certainly appeal to many. However, if you prefer sharper contours, you can gently enhance them with the appropriate slider in the TV menu. In this aspect, it's really hard to pick on anything. The image simply looks very good and additionally there is no problem with the phenomenon of overscan.

Smoothing and Distortion Reduction

The tonal transition smoothing feature fares a bit worse. In the settings, we find an option called “Distortion Reduction.” This allows for three levels of processor intervention adjustment. Unfortunately, the Minimum setting works poorly and the smoothing effects are negligible. The Medium level gives a decent result, but it also starts to smooth out the skin details of actors. On the other hand, the Maximum setting works too aggressively. It removes definitely too many details from the face and background elements or can even take away the film grain. To achieve the optimal effect, it's worth playing around with these settings at home and adjusting them to your preferences. It might seem that the Medium option represents the best compromise here.

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.

The motion representation in the OLED950 model is virtually perfect. This is typical for screens of this type (OLED 120Hz+), as the matrix shows no blurring at all. Thanks to this, we can enjoy flawless sharpness in practically any conditions. A big part of this is not only due to the specifics of organic technology. Equally important work is done by the smoothing systems implemented by the manufacturer.

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.

OLED950 is almost the perfect TV for gamers. This is not only due to the unique atmosphere that the Ambilight system creates during gameplay. The most important aspect here is the solid hardware support. We find literally everything that one should expect from a modern gaming screen today. The manufacturer has implemented two HDMI 2.1 ports with full bandwidth of 48 Gb/s. This gives us access to gaming in 4K resolution at 120 frames per second. Of course, support for VRR technology and the ALLM automatic game mode is also included. The device handles any HDR signal effortlessly, whether we are using Dolby Vision or the HGiG standard.

Access to all settings is available from one place thanks to the special Game Bar overlay. Although this interface may not be the most graphically attractive on the market, it fully serves its purpose. It displays all the most important signal parameters and offers useful additions. Gamers can take advantage of the mini-map zoom function or add a permanent crosshair on the screen, which can be seen as a small aid in online competition. Adjusting the contrast range also proves useful. It allows for brightening shadows and achieving better visibility of enemies hidden in the dark corners of the map.