LG OLED C5 vs TCL C9K

LG C5 finally does what we have been waiting for years in the C series – it exceeds 1000 nits of brightness! This is a significant change compared to previous models in the series, and it is very important – because most HDR content on streaming platforms is now created around such luminance. The image finally has the proper "shine," and the details in the highlights look as they should even without the use of dynamic metadata. However, there are scenes where the C5, like most OLED televisions, has certain issues. Especially when the screen needs to light up completely. In our test sequences, such as the bright shot from the film The Meg, the brightness clearly drops. Don't get us wrong, this result is not bad; it's more a reminder that OLED technology still has its limitations. Year by year they are becoming smaller, but still.

As for the colours? They are very good. Although the C5 does not match OLEDs with QD-OLED or Tandem RGB panels, the DCI-P3 coverage of 97% and 73% BT.2020 will satisfy even the more demanding viewers. The colours are saturated, natural, and very consistent in HDR material.

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.

LG C5, like other televisions we have tested, has been checked in the best possible factory mode – which remains the Filmmaker Mode. And here we have good news: in SDR materials, LG has once again done a solid job. The white balance and colour reproduction right out of the box are at a very high level. Most errors – both in balance and in the colour test (Colour Checker) – did not exceed a ΔE value of 3, which is the threshold above which differences become visible to the naked eye. Such factory settings would be desirable in a significantly larger number of televisions!

However, the situation looks different for HDR content, which is precisely what the C series was created for. Here, the C5 performs somewhat worse. The excessive presence of blue in the white balance causes the image to appear distinctly cooler – which affects, for instance, unnaturally pale skin tones or a slightly shifted tone of the entire scene. Fortunately, LG provides very precise calibration tools, and we – as always – made use of them.

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.

We must honestly admit – in the case of the LG C5, very little was needed to achieve nearly perfect picture quality. After calibrating, we managed to reach compatibility with reference screens at a level that impresses even when compared to significantly more expensive models. The image after our adjustment looks exactly as filmmakers and series creators would want it – without colour distortions, with natural depth and subtle texture. LG has done a great job this year regarding factory settings and calibration potential. Chapeau bas!

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.

LG C5 handles lower quality materials really very well. One of the main problems older WOLEDs faced was posterisation – that is, unwanted “stair stepping” in colour transitions. The C5 utilises a system feature that smoothens these transitions, which works surprisingly effectively. The banding effect is nearly completely eliminated, and the picture gains in coherence. Compared to last year's model, we have the impression that this feature works slightly less effectively – but the good news is that it does not undermine the structure of the image. Film grain, textures, and details remain on the screen – nothing is unnaturally smoothed out.

The C5 also excels at enhancing the quality of older recordings. Thanks to the α9 Gen6 processor (8th gen), the "scaling to 4K" performs really solidly. The image is clear, the details are sharp, and the only minor downside might be slightly noticeable edge sharpening on some borders. However, there is no issue with overscan here – the image is neither artificially cropped nor shifted, which is a significant plus and still not a given.

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 LG C5 is equipped with a 144 Hz display, and this, combined with the virtually zero response time of the OLED pixels, makes it one of the best screens for watching dynamic content. It doesn't matter whether it's sports, fast-paced games, or just action – the image is razor-sharp.

And what about movies at 24 frames? LG thought of that too. The built-in "TruMotion" smoother allows you to adjust the picture to your own preferences. The "de-judder" slider increases fluidity in films, while "de-blur" gently reduces motion blur – though to be fair, it is nearly invisible here anyway.

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.

LG C5 is a television designed with gamers in mind – and there isn't a hint of exaggeration in that. It's hard to find anything to criticise here. We have a refresh rate of 144 Hz, full support for VRR, ALLM, and as many as four HDMI 2.1 ports with a full bandwidth of 48 Gb/s. For those who have an Xbox, PS5, Nintendo, and a gaming PC all in one room – there are no limitations, everything can be connected without any hassle.

The HDR configuration for games also poses no problems. The television correctly handles the HGiG mode, which allows for an image that matches the creators' intentions. For those interested, there is also Dolby Vision in Gaming mode, although we still recommend HGiG as the most predictable and "pure" version of HDR in games.

It also features Game Bar, which serves as a "command centre" for gamers. Everything important, from VRR settings, to picture modes, to frame rate information – is at our fingertips. The interface is simple and clear. It may look like it’s from a spaceship simulator, but it serves its purpose and just works; as it should.

C5 is truly a complete set for any gamer.

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.