TCL C855 vs Philips OLED770

TCL C855 delivers a highly varied HDR effect. On one hand, the television truly shines, while on the other, it resembles a lower model with FALD backlighting. Such a state of affairs is regularly observed with this brand, so it was not a surprise for us. The first and last scene, which has large light elements, looks phenomenal, "shining" with brightness levels of 1470 and 1820 nits respectively. Such effects will certainly make many people squint, while simultaneously feeling the extraordinary dynamism of the scene itself. You can truly feel as if you were inside the movie. The situation drastically changes when small or minor elements with high luminance surrounded by black appear on the screen. The TCL C855, to avoid the halo effect, significantly reduces brightness to a level of even 240 nits, which is a disappointing outcome, causing the film to not look like it was shot in HDR. The HDR effect in TCL C855 makes watching dynamic scenes more engaging, and the viewer can feel like they are part of the action. Even with smaller elements of high luminance, the television manages to maintain details without excessive dimming. Moreover, the TCL C855 test shows that the brightness of the image is adapted to scenes with a large amount of detail, increasing viewing comfort.

The Philips OLED770 doesn't try to compete with the brightest OLEDs on the market, and it's actually hard to expect that, as it's the entry-level model in Philips' range for 2025. In our measurements, it reached a maximum of around 700 nits, which allows for enjoyment of HDR effects in scenes where light appears in spots – for instance, in the flash of headlights or a starry sky. In such moments, the picture can truly amaze. However, it's different when there are more bright elements on the screen. The TV, like many cheaper OLEDs, restricts luminance at that point, and the entire image noticeably dims. This was best seen in a scene from the movie The Meg, where the sun rises behind an oil platform – the brightness dropped to around 250 nits, which is almost three times less. The HDR effect remains pleasing to the eye, but it's worth being aware that this model performs best in scenes with less intense light. Fortunately, the OLED770 also has an ace up its sleeve – the coverage of the DCI-P3 colour palette is as high as 99%, so colours in movies and games are vibrant and very close to what the creator intended.

The best factory mode for the TCL C855 is "Film," and it is on this mode that we conducted all our tests. However, like every mode predefined by the manufacturer, it had flaws that are worth correcting to achieve an image that is as close as possible to what the film producer intended. We will look at the colour characteristics in both SDR and HDR materials. Taking the former into account, we see a clear dominance of green in the white balance, which, as you might guess, gave an unpleasant greenish tint to the entire image. Examining a very important gamma chart, responsible for the contrast of the image, we see a significant deviation from the reference line marked at 2.4. From the left, we can observe a strong spike in the measured value, which at this point caused contrast exaggeration and blending of details into a dark blob. This state of affairs persisted for quite a while, up to 20% of the chart’s value, before then diving below the reference. This, in turn, meant that the image was brightened and contrast decreased significantly. The factory mode performed somewhat better in HDR materials, as the white balance looked quite good, except for the second half, where green again took over. Looking at the EOTF curve, which, unlike gamma, shows the rate of brightness increase, we see primarily two errors: the darkest scenes were too dark, and the brightest ones were overexposed. This, by the way, could be observed in the scene from the film "Pan" in the check paragraph for the TV's HDR.

The first measurements already show that the factory settings of the Philips OLED770 have a lot to improve, even in Filmmaker mode. The white balance chart clearly indicates a lack of blue, giving the image a slightly yellowish tint. In practice, white is not snow-like, but leans towards warmer hues – which some may even find appealing, but from a precision standpoint, this is a deviation from the norm. The gamma, on the other hand, tends to be on the darker side – the average value is around 2.6 instead of the reference 2.4. In mid-tones, the image appears muted and more saturated, which can look too "cinematic" but detracts a bit from the naturalness. However, the most significant issues are visible in colour reproduction. The average error is relatively high, and some colours – particularly shades of grey – deviate significantly from what should be seen. In everyday viewing, this means that sometimes colours may look less natural than we would wish.

TCL, just like the vast majority of manufacturers, provides advanced calibration tools in its televisions. Here we find 2- and 20-point grey scale adjustments as well as an advanced colour management system. The results, as you can see, are very good and in SDR materials we have significantly approached the reference image. We eliminated both the green tint and the gamma issue, although there is still a slight "kink" at the very beginning. It went a bit worse with HDR materials, which the television ChooseTV C855 did not allow us to model properly. We only managed to slightly adjust the EOTF curve and significantly improve the colours themselves.

Philips OLED770 had shown signs from the start that it harboured significant potential, but it was hard to fully appreciate this in its factory settings. The image was often too warm, and some colours appeared as if they had lost their naturalness along the way. Calibration revealed that this television was very amenable to work – it responded to every adjustment and almost immediately unveiled another layer of its capabilities. The white balance was set in both SDR and HDR so that the yellowish haze disappeared and a neutral, clear white emerged. Gamma stabilised closer to perfection, which helped restore the naturalness of mid-tones, while shadows ceased to be artificially darkened, perhaps even with a slight brightening effect. The result was obvious... Movies are watched with greater ease; the image has cinematic depth without the feeling that something is overly darkened. However, the most interesting aspect was working on the colours. Factory errors were not dramatic, but slightly noticeable – skin tones could be too warm, and grey wasn’t always the shade we expected. After calibration, the error values dropped to around 2, and in many cases even below 1. This is a level that is definitely lower than the threshold of discernibility for the human eye. In other words, after correction, the colours finally “clicked” into place. Looking at the screen, we felt like the television had begun to speak with a full voice. Like an instrument that had finally been properly tuned.

Once again, we will 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 TV programs or older films. We will focus on the function responsible for tonal transitions. Interestingly, just like in the scenes in the previous test, it performed splendidly and smoothed out practically all the choppiness, but here it had problems. Using the menu responsible for the operation of this function, we found that none - not even the strongest - setting helped.

The image scaling in TCL C855 is characterised 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 contours, and there is no white halo around figures, which is characteristic of weaker scaling systems.

The problem of the previously mentioned colour connections can largely be mitigated thanks to the "distortion reduction" function, which is an algorithm for smoothing tonal transitions in Philips. It works best at a low level – effectively eliminating unwanted colour bands while not introducing strange artifacts or losing image detail. This is one of those features that is truly worth keeping on.

The issue of upscaling is somewhat less impressive. Images from lower resolution can be too soft, while in some parts the characteristic "jaggies" appear. The impression is that the algorithm is trying to reconcile two contradictory directions – smoothing and sharpening – and ultimately fails to find the golden mean. As a consolation, it's worth noting that the television does not have problems with overscan, meaning it does not cut off the edges of the image, which can sometimes happen in other competing models.

The maximum refresh rate that we can set on TCL C855 is 144 Hz. Naturally, this is only possible when connecting the TCL C855 TV to a very powerful PC. Otherwise, we will operate at a maximum refresh rate of 120 Hz, which is recommended if we primarily want to watch sports or content with a high level of motion dynamics. For those who require high fluidity of image, the manufacturer has implemented a multi-level motion smoother. It has been divided into two separate sliders that adjust the sharpness of moving images (Blur Reduction) and judder (Judder Reduction). Both sliders can be set in the range of 0 to 10, with each level affecting the degree of smoothing, so everyone can find their sweet spot. We present a setting that allows for slight smoothness without the soap opera effect.

The panel of TCL C855 features a very good response time. This is especially important, as VA panels often have issues with so-called ghosting, which is the effect where a black halo can be noticed behind a fast-moving object.

The issue of the panel in the Philips OLED770 is not entirely straightforward. The manufacturer claims a 120 Hz panel, but our measurements showed that the screen can accept a 4K signal even at 144 Hz. This sounds like great news – because who wouldn't want an additional mode for PC gamers at this price? However, the reality turned out to be more complex. With 120 Hz content, the television behaves like most OLEDs – the image is absolutely clear, with no trace of blurring or smearing, ideal for both dynamic games and sports broadcasts. The problem only arises at 144 Hz. Unlike models with official support for this frequency, here we see the phenomenon of so-called frame skipping. This means that the television is unable to display all the frames – some of them are skipped, causing motion to lose smoothness and double outlines to appear on the screen. The effect resembles the operation of the BFI function, which Philips does not offer in this model anyway.

The TCL C855 television is equipped with full HDMI 2.1 ports with a bandwidth of 48 Gb/s. During our tests, we confirmed the seamless operation of all functions that come with this standard. As you can see, all the checkboxes light up green, which will certainly be appreciated by gamers, both console and those using the television 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. Users with very powerful setups can provide a 144 Hz signal to the C855, which the television handles effortlessly. It's also worth mentioning the implementation of the HGIG mode, which, due to the shortcomings of the "Game" mode, is overly bright, making it difficult to configure properly on-screen. Fortunately, the television performs excellently with the Dolby Vision format.

The TCL C855, as one of the first manufacturers, has equipped its televisions with a special GameBar feature that allows extensive setting changes on the fly, without the need to exit the game. It includes functions such as an additional crosshair grid, black level correction, and settings for individuals with disabilities. In the photo, we see the next generation of this solution.

In summary, the TCL C855 television will be an ideal solution for those looking for a screen for any kind of electronic gaming. With all the features supporting such entertainment, it is incredibly engaging. It should also be emphasized that it has very low input lag, regardless of the selected settings, including with the Dolby Vision HDR format.

If someone is looking for a TV for gaming, the Philips OLED770 is a candidate that's hard to overlook. The mere fact that this is an OLED gives it a great starting point – perfect blacks and infinite contrast make evening sessions in atmospheric games look like they've been taken straight out of a cinema. Added to that is the Ambilight system, which uses LEDs on the back of the TV to extend the image onto the wall behind the screen. The effect is such that even just playing FIFA can look like a small spectacle, and in horror games, the atmosphere becomes really thick. On the technical side, it's also quite decent. The Philips OLED770 supports variable refresh rate (VRR) up to 120 Hz, has an automatic mode for gamers (ALLM), and for those using an Xbox Series X, Dolby Vision support in games is also available. You just need to know that in this mode, the input lag is slightly higher than standard, although still at an acceptable level. As a bonus, we also get the 'Game Bar', which is a special tool strip for gamers. It's not the most conveniently designed solution, but it allows for a quick view of key parameters without exiting the game. Overall, this gives a picture of a TV that has all the most important gaming features on one hand, and on the other can add something unique – Ambilight. And it's this mix of technology and visual effect that makes the OLED770 one of the better screens for gaming in a home environment.