LG OLED G4 vs TCL C9K

LG G4 guarantees an incredibly vibrant HDR effect, placing the television firmly at the top of the rankings. The highest model in the manufacturer's 2024 portfolio, equipped with the second generation of microlens technology (MLA), has achieved a maximum brightness level of 1474 nits in real scenes. The only area where the product of the Korean manufacturer may fall short compared to LCD televisions with Mini LED backlighting is during a full-screen scene featuring a lot of white. If we were to disregard the latter scene, the average result would be even higher. It's also worth mentioning scenes with very fine details, where each one shone at full intensity, which is not as evident in non-OLED televisions. The combination of such brightness and wide coverage of the DCI-P3 color space ensures that HDR materials are more engaging than ever before.

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 in terms of colour reproduction was "Filmmaker". This is the one we used during our tests. Let's check how its characteristics looked before the calibration process. Taking a closer look at the white balance first, we can notice a significant dominance of red and green colour. As a result, the image had a warm yellow tint. This is the kind of characteristic we usually observe in "Cinema", "Filmmaker", or similarly named modes. The effect of such a colour balance was clearly visible in both SDR and HDR content, which, after switching from "Standard" mode, was distinctly yellowed. Now let's move on to two graphs that are responsible for brightness characteristics, and consequently, image contrast. The first one (Gamma), representing materials with a standard colour palette, performed decently. For most of the time, the midtones and bright whites were represented very accurately, however, it noticeably lost the darkest details which blended into a black patch. On the other hand, HDR materials, represented by the EOTF curve graph, exhibited a significant drop in contrast due to a strong boost in brightness. There was also an issue with the colours themselves as seen on the "ColorChecker" graph since they were noticeably undersaturated.

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.

The manufacturer has been implementing extensive support for the calibration process in their LG televisions for many years. Therefore, we used 2- and 20-point grey scale adjustments along with an advanced CMS (Color Management System) and got to work. As you can see, thanks to the procedure carried out, each of the parameters has significantly improved. The use of tools has resulted in extremely beneficial effects, which include: studio colour reproduction, recovery of details in dark areas of the image, appropriate brightness characteristics, and proper colour saturation. Thus, we have maximised our approach to the reference image, or the one that the film director saw on the preview monitor. It is worth noting that the LG G4 televisions are the only ones that allow for even deeper intervention in image quality due to the capability to calibrate with 3D LUT matrices. However, this solution is recommended only for post-production or graphic studios.

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.

The tested television did not perform well with content rich in tonal transitions, resulting in a strong posterisation effect. However, there is a partial remedy for this ailment. The manufacturer has equipped the LG G4 with a smoothing system called "Gentle Gradation," which we can apply at three levels: Low, Medium, and High. Each of these options guarantees quite high smoothing effectiveness on bright colours, though low on darker ones. We recommend primarily using the first one due to the fact that the other two interfere with directorial intentions, removing film grain.

When watching lower-quality content, the efficiency of the television during upscaling is extremely important. The image from the tested television is sharp and clear. However, attention should be paid to the jagged edges of fine details and minor issues around characters, such as the creation of a halo effect, which occurs due to the sharpening imposed by the LG G4 even when the slider is set to the lowest value, which is 0. It is worth noting that this is a change in relation to the LG G3, which did not impose such strong image sharpening, even when the appropriate slider was set to position 0.

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 that we can set on the LG G4 is 144 Hz. Naturally, this is only possible by connecting the LG G4 to a very powerful PC. Otherwise, we will be operating at a maximum refresh rate of 120 Hz, which is recommended if we primarily want to watch sports or content with high motion dynamics. For those who require high fluidity of 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 from 0 to 10, with each increment affecting the degree of smoothing, so everyone can find their sweet spot.

The LG OLED G4 panel features an average response time of 0.78 ms (which directly results from our measurements), allowing for an incredibly clear image, unattainable by LCD televisions, which have response times of even several milliseconds. This is clearly visible in the "UFO Test" images, showing the absence of any trailing blur behind the object. Furthermore, the LG OLED G4 test showed that the television offers the ability to precisely adjust motion smoothing functionality, allowing users to choose the ideal level of image interpolation. We particularly appreciated this during fast-paced action in video games, where the LG G4 performed exceptionally well, minimising any blurriness. Thanks to OLED technology, this model eliminates so-called ghosting, ensuring that the image remains sharp even in the most dynamic sports or movie scenes.

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.

The LG G4 television supports all features that make up the HDMI 2.1 standard. During testing, each feature activated without any issues, which allows us to consider the television as designed for gaming. Its performance will certainly be appreciated by both console users and those connecting the LG G4 to a computer. It’s also worth mentioning the proper implementation of the HGIG (HDR Gaming Interest Group) mode, which ensures that games mastered to brightness levels beyond the maximum luminance of the LG G4 will correctly map tones, keeping the game image true to the original.

A nice touch is the presence of a special GameBar that we can bring up at any moment to check game parameters, but most importantly, to change them quickly. More importantly, turning on VRR technology does not degrade contrast, which is often a problem in televisions with local dimming or Mini LED backlighting. Of course, this is thanks to the OLED panel itself, characterised by pixel self-emissiveness. As a journalistic note, we will only mention a slight grey flicker, which, however, is somewhat normal when VRR is enabled.

In summary, the LG G4, like practically all OLED televisions, is an ideal product for all kinds of gaming and online competitions. With full HDMI 2.1 ports with a complete bandwidth of 48 Gbit, features such as VRR, ALLM, G-Sync, FreeSync, or HDR Dolby Vision gameplay will bring a lot of joy.

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.