TCL C9K vs Hisense U7S / U77SE

As we mentioned with black and contrast – the C9K makes 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 cosmic, but – and here unfortunately the pattern repeats – the numbers say one thing, and practice another. In real film scenes, the situation looks different. In the best case, when the light effects occupy a large part of the image and the local dimming algorithm doesn't have to think too hard about what to do with thousands of zones – the result is really quite good. At that point, the C9K can reach about 1500 nits, which provides a pleasant, intense flash and can indeed make a positive impression.

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

The Hisense U7S has considerable potential for HDR display, but it cannot exploit that potential in every scene. On a test pattern it reaches around 1,100 nits, so the backlight itself is very strong. In our brighter film scenes we measured about 640 to 745 nits. That is still plenty for the sun or bright highlights to have a clear bloom and to show an advantage over SDR material. When the TV needs to brighten a larger portion of the image, it handles it fairly well.

The problem appears with small highlights on a dark background. Each of the 192 zones covers an area much larger than a tiny point on the screen. If the TV were to light that whole zone strongly, it would also brighten the area around the highlight. Hisense tries to avoid that and dims the entire zone. This makes blacks look better, but a small bright object that should attract the eye also loses intensity. That is why in two more demanding scenes we recorded only 297 and 154 nits. The difference is large: in one shot HDR can impress, and in the next small highlights are noticeably muted. The U7S therefore prioritises preserving deep blacks, even at the expense of bright details. With that number of zones it is an understandable compromise, but worth bearing in mind — the peak 1,100 nits tells us about the backlight’s capability, not how brightly the TV will show every element of a film.

Colours

Hisense describes the U7S as ULED, but that is a marketing name, and it is a PFS phosphor backlight that expands the colour palette here. In our measurements the TV covered about 91% of the DCI-P3 colour space and 71% of BT.2020. Those are good results, though they fall short of the best screens on the market. The largest shortfall is in green — the TV does not even reach the DCI-P3 boundary here, so the most intense shades will be less saturated than they should be. Most colours in HDR films and series still look suitably vibrant. A positive is the repeatability of the results. Gamut coverage on test patterns and in film scenes is practically identical.

For colour tests, we once again reached for the Filmmaker mode – a new feature in TCL televisions for 2025. And although 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. Conversely, in HDR, it swung in the opposite direction: the image became excessively blue. The Colour Checker test revealed quite a few colour inaccuracies that were noticeable to the naked eye. An even bigger problem turned out to be what we mentioned above – managing brightness. Regardless of whether we were watching SDR or HDR content, the image had a tendency to blow out the entire scene, giving it an unnatural, almost grotesque character. Therefore, it is hard to call this a 'director’s mode' – because the director surely has never seen such an image.

Out-of-the-box colours on the Hisense U7S are decent, but there are a few areas to improve. In SDR there is a red bias in the white balance, which makes the picture too warm and, in places, slightly pink. You can notice this on faces and on bright, neutral surfaces. The gamma also runs below the target, so the TV brightens the image, particularly in darker areas. That makes shadow detail easier to see, but the scene loses some of its depth.

In HDR the white balance is somewhat more even, but not entirely neutral, with a shortage of blue in the mid-tones and a lack of red in the brightest parts. A bigger issue is how brightness is rendered. The EOTF curve shows a large portion of the mid-tones being lifted, causing the picture to look brighter than the source intends. Color Checker measurements are also weaker than in SDR: many errors are around 3 to 4, and some reach as high as 8. Colours can therefore look attractive, but they are not always faithful to what we should see. There is room for improvement here and we will see how much can be corrected through calibration.

After calibration, we finally managed to tame the white balance – and it immediately translated into a more natural image. Colours finally started to look as they should, and the overall presentation was incomparably better than with the factory settings. In other words – it’s worth taking a moment to improve this, as the gain is really significant. The gamma responsible for managing brightness was also brought under control in SDR content, and the effect was more than satisfactory. Unfortunately, when we switched on the HDR material, the situation quickly became complicated. No matter how we set the local dimming, the television had a tendency to do what it pleased with the image – either overexposing the whole picture or dimming the darkest parts too much. Just like we saw in the scene from the film Billy Lynn. Colour-wise, the improvement after calibration makes a great impression, but managing brightness in HDR remains the Achilles' heel of the C9K and constitutes a technological limitation.

Calibration of the Hisense U7S brought the biggest improvements with SDR material. We managed to even out the white balance, so the previous warm tint has gone and whites and greys now look neutral. Gamma is also now very close to the reference, and the TV no longer brightens the picture unnecessarily, so darker scenes have regained depth. Color Checker measurements confirm the improvement: most errors are below 2. That means the picture is very well set up for watching regular TV and SDR films. It wasn't as smooth in HDR. There is no effective way to correct the EOTF curve, so the TV still interprets a film's brightness somewhat on its own. It brightens parts of the picture and can dim the brightest elements depending on the scene and the behaviour of the local dimming. Calibration could not eliminate this. This is also reflected in the Color Checker results, where many errors remain around 3–4 and a few exceed 7. So the result in SDR is really very good, but in HDR we must accept that the TV adds its own interpretation of brightness to the image.

The digital image processing in TCL C9K is rather mediocre. The tone transition smoothing feature is supposedly present, but activating it hardly makes any difference – colour banding is still visible, and it can inadvertently highlight elements we would prefer to hide, such as textures of objects. Fortunately, it does not remove film grain, but that's scant consolation considering the effects are still poor. Thus, it's hard to recommend using this option.

On the other hand, image scaling performs significantly better. Lower quality materials look quite decent – characters and backgrounds are represented clearly, although of course, with sources like 576p, the limitations of the physics cannot be disguised. Sometimes, there's characteristic aliasing of objects, but that's due to the source itself, not the algorithm. A plus for the fact that there are no overscan issues – the image is neither artificially cropped nor enlarged.

The handling of lower-quality material is fairly mediocre on the Hisense U7S. The Pentonic 700 chipset used here does not cope particularly well with strong compression artefacts. The menu includes a "Smooth and Gradient Image" function, but its performance leaves much to be desired. At the low setting tonal transitions show little improvement, although at least the image does not suffer. The medium and high settings still do not remove obvious banding between shades, and they begin to blur details; in our test material even parts of characters' faces disappeared. Interestingly, film grain remains untouched at every level. If you do use this feature, stick to the low setting. Its current behaviour needs refinement, but that is mainly down to the chipset used here.

Upscaling to 4K performs much better. Lower-resolution content gains in legibility, edges are well reproduced, and fine elements look sharp. That does not mean it recovers details that were never in the recording, but the TV makes good use of what it receives from the source. Another plus is that it does not crop the image edges, even with an SD signal.

Similar to the C8K, the C9K is also a really fast television – both figuratively and literally. On board, we have a 4K panel with a refresh rate of 144 Hz, and at lower resolutions, the panel can even ramp up to 288 Hz. Such speed translates into practice – while watching sports or playing games, the picture looks very smooth and clear. Additionally, in films, we get an extra motion smoothing feature called Motion Clarity, which allows you to adjust the smoothness to your own preferences – from the cinematic "stuttering" of frames to nearly theatrical smoothness.

Motion handling on the Hisense U7S is decent thanks to the 144 Hz refresh rate. For films there is also a motion smoother with adjustable judder and blur reduction. You can therefore keep a more cinematic motion or increase smoothness if jerky camera pans bother you. The high refresh rate is also useful for sports and gaming, but unfortunately it does not solve the panel's biggest problem.

That problem is pixel response time. Fast-moving objects leave long, clearly visible trails, as our UFO test shows. It looks worst on dark backgrounds, where the trail behind the object is particularly pronounced. So motion can be smooth, but the moving object itself loses sharpness, and that difference on the U7S is fairly easy to notice.

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 the key technologies work: VRR (Variable Refresh Rate) and ALLM (Auto Low Latency Mode). Additionally, the manufacturer has included a really intuitive Game Bar, which allows you to quickly check the most important parameters and adjust settings without rummaging through the menu. Also worth noting is TCL's policy – the television does not shy away from 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 a wide range of freedom.

The Hisense U7S has a lot to offer gamers. You get two HDMI 2.1 ports and support for 120 Hz at Full HD, 1440p, and 4K, so modern consoles’ capabilities are well used. When connected to a PC you can use 144 Hz at 4K or switch the resolution to Full HD and run 240 Hz. So there’s a wide choice, although it’s worth remembering the motion smearing mentioned earlier, which the high refresh rate does not eliminate. VRR and ALLM are also present. The first helps prevent tearing when frame rates in a game change. The second automatically switches the TV into game mode, so you don’t have to dig through the menu each time. VRR works from 48 to 240 Hz, with the highest refresh rate available in Full HD. Xbox users can also play in Dolby Vision, including at 120 Hz. Importantly, this format does not introduce significant input lag here. The Game Bar also looks very good. It’s easy to read, visually appealing, and lets you quickly check what signal the TV is receiving. There are also handy gaming settings at your fingertips, including shadow brightening. If it’s hard to spot an opponent in a dark game, you can improve visibility without digging through the entire menu.

Our biggest complaints concern HGiG. Hisense continues to do its own tone mapping, which makes setting HDR on the console confusing. You adjust a checkerboard test pattern and the TV continuously adapts how it looks. As a result, the moment the pattern disappears does not correctly indicate the screen’s brightness limit, and it’s easy to set the value too high. For this model it’s better to set the target HDR peak brightness on the console to about 900 to 1000 nits, rather than relying on the configurator.