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 also very important – because this is exactly the level of luminance around which most HDR content is now created on streaming platforms. The image finally has the right “glow,” and details in bright areas look as they should even without the use of dynamic metadata. However, there are scenes where the C5, like most OLED televisions, has some issues. Especially when the screen needs to illuminate fully. In our test sequences, such as the bright scene from the movie The Meg, brightness clearly decreases. Don’t get us wrong, this result isn’t bad; it’s more of a reminder that OLED technology still has its limitations. They are getting smaller year by year, but still.

Now, what about the colors? They are very good. Although the C5 does not match the OLEDs with QD-OLED or Tandem RGB panels, the DCI-P3 coverage at 97% and 73% BT.2020 will satisfy even the most demanding viewers. The colors are saturated, natural, and very consistent in HDR materials.

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.

LG C5, like other TVs we tested, was checked in the best possible factory mode – which remains Filmmaker Mode. And here we have good news: in SDR materials, LG once again did a solid job. The white balance and color reproduction straight out of the box are at a very high level. Most errors – both in balance and in the color 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 are something we would like to see in many more TVs!

However, the situation is different for HDR content, which is really what the C series was created for. Here the C5 performs weaker. The excessive presence of blue in the white balance causes the image to appear noticeably cooled – which affects, for instance, unnaturally pale skin tones and somewhat shifted tonality of the entire scene. Fortunately, LG provides very precise calibration tools, and we – as always – took advantage of them.

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.

We must honestly admit – in the case of the LG C5, it took really very little to achieve an almost perfect picture. After calibration, we managed to achieve compliance with reference screens at a level that impresses even compared to much more expensive models. The picture after our adjustment looks exactly as filmmakers and series creators would want it – without color distortions, with natural depth and subtle texture. LG has done a great job this year regarding factory settings and calibration potential. Hats off!

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.

LG C5 handles lower-quality materials really well. One of the main issues older WOLEDs faced was posterization – unwanted "steps" in color transitions. The C5 uses a system feature to smooth these transitions, which works surprisingly effectively. The banding effect is almost completely eliminated, and the image gains consistency. Compared to last year's model, we feel that this feature works slightly weaker – but the good news is that it does not compromise the structure of the image. Film grain, textures, and details remain on the screen – nothing is smoothed out forcefully.

The C5 also does a great job of enhancing the quality of older recordings. Thanks to the α9 Gen6 processor (8th gen), "scaling to 4K" performs really solidly. The image is clear, the details are sharp, and the only minor drawback might be slightly visible jaggedness on some edges. However, there is no issue with overscan here – the image is not artificially cropped or shifted, which is a significant plus and still isn’t a given.

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 LG C5 is equipped with a 144 Hz panel, and this, combined with the practically 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 as sharp as a razor.

And what about movies in 24 frames? LG thought of that too. The built-in "TruMotion" smoother allows you to adjust the image to your own preferences. The "de-judder" slider increases the smoothness in movies, while "de-blur" gently reduces blurring – although to be fair, it is almost imperceptible here anyway.

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.

LG C5 is a television designed with gamers in mind – and there’s not a hint of exaggeration in that. It's hard to find anything to criticize here. We have 144 Hz refresh rate, full support for VRR, ALLM, and up to four HDMI 2.1 ports with 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 limits, everything can be connected without any hassle.

The HDR configuration for gaming is also problem-free. The television properly supports the HGiG mode, which allows for an image consistent with the creators' intentions. For those interested, there’s also Dolby Vision in Gaming mode, though we still recommend HGiG as the most predictable and “pure” version of HDR for games.

The Game Bar is also included, which serves as the “command center” for the gamer. Everything that’s most important, from VRR settings, to picture modes, to frame rate information – is at our fingertips. The interface is simple and readable. It may look like something out of a space simulator, but it serves its purpose and just works; exactly as it should.

C5 is truly a complete package for every 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 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.