LG OLED C4 vs TCL C9K

The results of HDR materials are definitely among the better ones. Practically every film significantly exceeds the 700 nits barrier, which allows for a very realistic image. Of course, none of them surpasses the magical thousand, however, the combination of such results along with unlimited contrast and black effectively boosts the visual outcome. The last of the scenes, featuring a fullscreen sun burst, is indeed less bright than the others, although it still represents a respectable level. It's also worth mentioning the excellent coverage of the DCI-P3 colour palette, which will enable the achievement of exceptionally vivid colours.

As we mentioned regarding black levels 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 can achieve... 4000 nits of brightness! It sounds out of this world, but – and here's where the pattern unfortunately repeats – the numbers say one thing, and the practical experience says another. In real movie scenes, the situation looks different. In the best-case scenario, when light effects occupy a large part of the image and the local dimming algorithm doesn't have to ponder too much about what to do with thousands of zones, the effect is really quite good. At that point, the C9K can hit around 1500 nits, which delivers a pleasant, intense burst and can indeed leave a positive impression.

The problem arises 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 to as low as 400–500 nits. That's a huge difference from the potential 4000 nits we saw in lab tests. Why does this happen? Most likely, the television is trying to protect the black levels in this way and minimize the halo effect around bright objects. Unfortunately, this comes at the expense of detail – some details simply vanish, and the scene loses its nature.

The best factory mode implemented in the tested television was "Filmmaker". That was the one we used during all tests. This mode, in terms of colour reproduction, turned out to be quite decent, although other flaws effectively detracted from the enjoyment of the viewing experience. Starting with the most basic one, which is white balance, it was easy to notice that this was marked by a dominance of red, which completely altered the characteristics of the picture. We could see a strong yellowing of the whites and a shift of all colours to warmer tones. The gamma, which is a graph as equally important, if not more so, was quite severely reduced, resulting in a significant drop in contrast, except for the start of the graph, where the television insidiously lost details. That’s all regarding SDR materials. Looking closely at films with a wide dynamic range, we can observe exactly the same phenomenon of white balance yellowing as in films with a standard colour palette. The EOTF curve, which replaces the gamma chart for us, is practically perfect and cannot be faulted.

For colour tests, we once again reached for the Filmmaker mode – a new feature in TCL televisions for 2025. While the direction is a step in the right way, the execution leaves a lot 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 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 – brightness management. Regardless of whether we were watching SDR or HDR content, the image tended to wash out the entire scene, giving it an unnatural, almost grotesque character. Therefore, it’s hard to call this a "director's mode" – because no director has ever seen such an image.

As we mentioned earlier, LG televisions are equipped with advanced tools for carrying out the calibration process. We used them to model the picture in line with what the director envisioned. And without modesty, we must admit that we achieved this phenomenally. Both SDR and HDR materials present a level that clearly indicates this is how a film should look. It's worth taking a look at the colour errors on the "ColorChecker" palette, where practically none of them exceed "1", except for two samples.

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 on 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 brightness management also managed to be brought into order in SDR content, and the effect was more than satisfactory. 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 darkened the darkest parts too much. Just like we saw in the scene from the movie Billy Lynn. Colour-wise, the improvement after calibration makes a great impression, but brightness management in HDR remains the Achilles' heel of the C9K and presents a certain technological limitation.

Once again, we will take a look at the feature responsible for gentle gradation, but we will also address the one that aims to enhance the quality of lower-quality materials. The default smoothing of tonal transitions, as we could see, was not the worst, but it can be improved further. The function has a slider that allows us to adjust its intensity. We recommend using the former, as it produces very good results and does not blur important details.

Image scaling on LG C4 is quite good, however, it cannot be said to be without flaws. The image is slightly sharper by default, although not in a very noticeable way. While jagged edges of trees can be seen, it is not a major issue when compared to other manufacturers.

Digital image processing on the TCL C9K is rather average. The smooth tone transition feature seems to be present, but activating it practically changes nothing – colour bands are still visible, and it can unintentionally highlight elements we’d rather keep hidden, such as object textures. Fortunately, it doesn’t remove film grain, but that’s poor consolation given that the effects are still meagre. It’s therefore hard to recommend using this option.

On the other hand, image scaling presents itself much better. Lower quality materials look quite decent – characters and backgrounds are rendered clearly, although of course, with sources like 576p, the laws of physics cannot be fooled. Occasionally, there’s characteristic edge distortion of objects, but that’s the fault of the source itself, not the algorithm. A plus for not having issues with overscan – the image isn't artificially cropped or enlarged.

The maximum refresh rate we can set on the LG G4 is 144 Hz. Naturally, this is only possible when connecting the 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 lot of motion dynamics. For those who require high fluidity of the image, the manufacturer has implemented a multi-level motion smoother called "TrueMotion". It has been divided into two separate sliders that adjust the sharpness of moving images (De-Blur) and judder (De-Judder). Both sliders can be set in the range of 0 to 10, with each degree affecting the level of smoothing, allowing everyone to find their sweet spot.

The panel of the LG OLED C4 features an average response time of less than 1 ms (which directly results from our measurements), enabling the achievement of an extremely clear image, unattainable for LCD TVs, which can have response times of up to several milliseconds. This is clearly evident in the images from the "UFO Test," which show no trailing blur behind the object.

Similar to the C8K, the C9K is also a really fast TV – both figuratively and literally. It features 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 image looks very smooth and clear. Additionally, in movies, we get an extra motion smoother called Motion Clarity, which allows you to adjust the smoothness to your own preferences – from cinematic "judder" to almost theatrical smoothness.

We can now say that LG C4, like practically every OLED television from the manufacturer, is exceptionally good in terms of cooperation with consoles and PCs. Thanks to the implementation of four full-bandwidth HDMI 2.1 ports at 48 Gbps, the manufacturer has embedded all the features that enhance gaming comfort, including simultaneous support for FreeSync and G-Sync technologies. With such a tandem, players with graphics cards from AMD or nVidia can safely choose C4. However, what should please gamers demanding the highest possible quality the most is the simultaneous implementation of HDR Dolby Vision and HGIG mode. The former is particularly important as it operates with extremely low input lag in all settings.

A standard feature in televisions from the Korean manufacturer is also the implementation of GameBar, allowing for quick adjustments of settings "on the fly," without the need to exit the game. It also allows for image adjustments for people with visual impairments, which is an incredibly nice touch. Another important piece of information is that when VRR technology is enabled, we won’t experience a drop in contrast. This is, of course, due to the design of the panel and the absence of conventional backlighting. It is, however, normal for shades of grey to flicker slightly, although this is a characteristic feature of this function regardless of the manufacturer and television.

In summary: LG C4, just like all the manufacturer's OLEDs equipped with high-refresh-rate panels and HDMI 2.1 connections, creates a harmonious whole with consoles. In practice, it is a complete television, and if we expect the highest possible efficiency in gaming, C4 will be an ideal choice.

From a gaming perspective, the TCL C9K is a complete tool. It features two (out of four) full bandwidth 48 Gbps HDMI 2.1 ports, 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 that allows you to quickly check the most important parameters and adjust settings without fumbling through menus. Also, TCL's policy is a plus – the TV isn’t 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 plenty of freedom.