TCL C9K vs Philips OLED770

As we mentioned with black and contrast – the C9K can make a huge impression in synthetic tests. Our measurements showed that on a screen 10% filled with white, the television is capable of squeezing out… 4000 nits of brightness! It sounds astronomical, but – and here, unfortunately, the pattern repeats – the numbers say one thing, and practice says another. In real movie scenes, the situation looks different. At best, when the light effects occupy a large part of the image and the local dimming algorithm does not have to think too hard about what to do with thousands of zones – the effect is really good. At that point, the C9K can reach around 1500 nits, which provides a pleasant, intense flash and can indeed make a positive impression.

The problem starts with smaller elements – such as stars in the sky, the moon, or single reflections. That’s when the proverbial cat comes out of the bag: the algorithms are not yet refined, and brightness drops to even 400–500 nits. That’s a huge difference compared to the potential 4000 nits we saw in laboratory tests. Why does this happen? Most likely, the television is trying to protect the blacks in this way and minimize the halo effect around bright objects. Unfortunately, this comes at the cost of details – some details simply vanish, and the scene loses its nature.

The Philips OLED770 does not attempt to compete with the brightest OLEDs on the market, and it would actually be hard to expect that, as it is the lowest model in Philips's series for 2025. In our measurements, it achieved a maximum brightness of about 700 nits, which allows for enjoyment of HDR effects in scenes where light appears point-wise – for example, in the flash of headlights or a starry sky. In such moments, the picture can truly impress. However, it is different when there are more bright elements on the screen. The television, like many cheaper OLEDs, limits brightness in those cases, and the entire picture noticeably dims. This was best seen in a scene from the movie The Meg, where the sun rises behind an oil rig – at that point, the brightness dropped to about 250 nits, nearly three times less. The HDR effect remains visually pleasing, but it is worth being aware that this model performs best in scenes with less intense light. Fortunately, the OLED770 has an ace up its sleeve – the coverage of the DCI-P3 color palette is as high as 99%, so colors in movies and games are saturated and very close to what the creator intended to convey.

For color tests, as always, we reached for the Filmmaker mode – a new feature in TCL TVs for 2025. And while the direction itself is a step in the right direction, the execution leaves much to be desired. The white balance in SDR content turned out to be too warm – there was an excess of red. On the other hand, in HDR, it went in the opposite direction: the image became excessively blue. The Colour Checker test revealed quite a few color errors that were noticeable to the naked eye. An even bigger problem turned out to be what we mentioned above – brightness management. Regardless of whether we were watching SDR or HDR content, the image tended to blow out the entire scene, giving it an unnatural, even grotesque character. It's hard to call this a "director-created" mode – because the director has certainly never seen such an image.

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 shows a lack of blue, which gives the image a slightly yellowish tint. In practice, the white is not snow-white, but leans towards warmer hues – which some may even like, but from the accuracy perspective, this is a deviation from the norm. The gamma, on the other hand, tends to be on the darker side – the average value is about 2.6 instead of the reference 2.4. In the mid-tones, the image appears muted and more saturated, which may look too "filmic," but takes away some naturalness. However, the biggest issues can be seen in color reproduction. The average error is relatively high, and some colors – especially shades of gray – clearly deviate from what should be seen. In everyday viewing, this means that sometimes colors may look less natural than we would wish.

After calibration, we finally managed to tame the white balance – and it immediately translated into a more natural image. Colors finally started to look the way they should, and the overall presentation was incomparably better than in the factory settings. In other words – it’s worth taking a moment to improve this, as the gain is truly significant. The gamma responsible for managing brightness was also brought into order in SDR content, and the effect was more than satisfying. Unfortunately, when we turned on HDR materials, the situation quickly became complicated. No matter how we set the local dimming, the television had a tendency to do what it liked with the image – either it overexposed everything or dimmed the darkest parts too much. Exactly as we saw in the scene from the movie Billy Lynn. So, the color improvement after calibration makes a great impression, but brightness management in HDR remains the Achilles' heel of C9K and presents a certain technological limitation.

Philips OLED770 has shown signs from the beginning that it houses significant potential, but it was difficult to fully see this in the factory settings. The image was sometimes too warm, and some colors seemed to have lost their naturalness along the way. However, calibration revealed that it is a television very receptive to adjustments – it reacted to every correction and almost immediately unveiled another layer of its capabilities. The white balance was successfully set both in SDR and HDR, eliminating the yellowish glow and presenting a neutral, clear white. Gamma stabilized closer to perfection, allowing midtones to regain their naturalness, and shadows no longer appeared artificially darkened, possibly even with a slight brightening effect. The effect was obvious... Movies are watched with greater ease; the image has cinematic depth, but without the feeling that something is exaggeratedly darkened. However, the most interesting part was the work on colors. Out of the box, the errors were not dramatic but slightly noticeable – skin tones were sometimes too warm, and gray didn’t always have the shade we expected. After calibration, the error values dropped to around 2, and in many cases even below 1. This is a level significantly lower than the threshold of perception for the human eye. In other words, after correction, the colors finally “clicked” into place. Looking at the screen, we had the impression that the television had begun to speak with a full voice. Like an instrument that has finally been well-tuned.

Digital image processing in TCL C9K is quite mediocre. The tonal smoothing feature seems to be present, but turning it on practically changes nothing – color bands are still visible, and it can unintentionally highlight elements we would prefer to hide, such as textures of objects. Fortunately, it doesn’t remove film grain, but that’s small comfort since the effects are still poor. Therefore, it's hard to recommend using this option.

On the other hand, image scaling performs much better. Lower quality materials look quite decent – characters and backgrounds are presented clearly, although, of course, with sources at 576p, physics cannot be fooled. Sometimes, characteristic aliasing on objects appears, but that’s the fault of the source itself, not the algorithm. A plus for not having issues with overscan – the image is not artificially cropped or enlarged.

The problem of the previously mentioned color connections can largely be mitigated by the "distortion reduction" feature, which is an algorithm for smoothing tonal transitions in Philips TVs. It works best at a low setting—effectively eliminating unwanted color bands while not introducing strange artifacts or losing image detail. It's one of those features that is truly worth keeping switched on.

The issue with upscaling is somewhat less favorable. The image from a lower resolution can be too soft, while at the same time, distinctive "jaggies" appear in certain areas. The impression is that the algorithm is trying to reconcile two contradictory directions—smoothing and sharpening—and ultimately hasn't found the golden mean. As a consolation, it's worth noting that the television has no issues with overscan, meaning it doesn't cut off the edges of the image, which sometimes happens with other competing models.

Like the C8K, the C9K is also a really fast television – both figuratively and literally. It features a 4K panel with a refresh rate of 144 Hz, and at lower resolutions, the display can even ramp up to 288 Hz. This speed translates into practice – when watching sports or playing games, the image looks very smooth and clear. Additionally, in films, we get an extra motion smoother called Motion Clarity, which allows us to adjust the fluidity to our own preferences – from the cinematic "judder" frame to almost theatrical smoothness.

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 extra mode for PC gaming at this price? However, the reality turned out to be more complex. With 120 Hz materials, the television behaves like most OLEDs – the picture is absolutely clear, with no trace of ghosting or blurring, making it ideal for both fast-paced games and sports broadcasts. The problem arises only at 144 Hz. Unlike models with official support for that frequency, here we observe the phenomenon of so-called frame skipping. This means that the television is unable to display all frames – some of them are skipped, causing the motion to lose fluidity, and double outlines appear on the screen. The effect resembles the operation of the BFI function, which Philips does not offer in this model anyway.

For gaming, the TCL C9K is a complete tool. Here we have two (out of four) HDMI 2.1 ports with full bandwidth of 48 Gbps, so all key technologies work: VRR (variable refresh rate) and ALLM (automatic low latency mode). Additionally, the manufacturer added a really intuitive Game Bar, which allows you to quickly preview the most important parameters and adjust settings without digging through the menu. Also, TCL's policy is a plus – the TV is not afraid of any HDR formats, even in game mode. Whether it's HGiG or Dolby Vision for the Xbox Series S/X console – everything works as it should, giving the player wide freedom.

If someone is looking for a gaming TV, the Philips OLED770 is a candidate that's hard to ignore. The mere fact that we have an OLED here provides a great starting point – perfect blacks and infinite contrast make evening sessions in atmospheric games look like they’ve been pulled straight from the cinema. On top of that, there’s the Ambilight system, which features LEDs on the back of the TV that extend the image onto the wall behind the screen. The effect is such that even regular gameplay in FIFA can look like a small spectacle, and in horror games, the atmosphere becomes really intense. On the technical side, it’s pretty good as well. The Philips OLED770 supports Variable Refresh Rate (VRR) up to 120 Hz, has an automatic low latency mode for gamers (ALLM), and if someone is using an Xbox Series X, they can also count on Dolby Vision support in games. You just need to know that in this mode, input lag is slightly higher than standard, although still at an acceptable level. As a bonus, we get the “Game Bar” panel, which is a special tool strip for gamers. It's not the most conveniently designed solution, but it allows you to check key parameters without leaving the game. In total, this presents a picture of a TV that on one hand has all the most important gaming features, 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.